Provided by: graphicsmagick_1.4+really1.3.38-1ubuntu0.1_amd64 bug

SYNOPSIS

       gm animate [ options ... ] file [ [ options ... ] file ... ]

       gm batch [ options ... ] [ script ]

       gm benchmark [ options ... ] subcommand

       gm compare [ options ... ] reference-image [ options ... ] compare-image [ options ... ]

       gm composite [ options ... ] change-image base-image [ mask-image ] output-image

       gm conjure [ options ] script.msl [ [ options ] script.msl ]

       gm convert [ [ options ... ] [ input-file ...  ] [ options ... ] ] output-file

       gm display [ options ... ] file ...  [ [options ... ]file ... ]

       gm identify file [ file ... ]

       gm import [ options ... ] file

       gm mogrify [ options ... ] file ...

       gm montage [ options ... ] file [ [ options ... ] file ... ] output-file

       gm time subcommand

       gm version

DESCRIPTION

       GraphicsMagick's  gm  provides  a  suite of utilities for creating, comparing, converting,
       editing, and displaying images.  All of the utilities are provided as  sub-commands  of  a
       single gm executable.  The gm executable returns the exit code 0 to indicate success, or 1
       to indicate failure:

       animate displays an animation (e.g. a GIF file) on any workstation display  running  an  X
       server.

       batch  executes an arbitary number of the utility commands (e.g. convert) in the form of a
       simple linear batch script in order to improve execution efficiency, and/or to  allow  use
       as a subordinate co-process under the control of an arbitrary script or program.

       benchmark executes one of the other utility commands (e.g. convert) for a specified number
       of iterations,  or  execution  time,  and  reports  execution  time  and  other  profiling
       information  such as CPU utilization. Benchmark provides various operating modes including
       executing the command with a varying number of threads, and  alternate  reporting  formats
       such as comma-separated value (CSV).

       compare  compares  two  images  and  reports  difference statistics according to specified
       metrics and/or outputs an image with a visual representation of the differences.   It  may
       also be used to test if images are similar within a particular range and specified metric,
       returning a truth value to the executing environment.

       composite composites images (blends or merges images together) to create new images.

       conjure interprets and executes scripts in the Magick Scripting Language (MSL).

       convert converts an input file using one image format to an output file with the  same  or
       differing image format while applying an arbitrary number of image transformations.

       display  is  a  machine architecture independent image processing and display facility. It
       can display an image on any workstation display running an X server.

       identify describes the format and characteristics of one or more image files. It will also
       report if an image is incomplete or corrupt.

       import  reads  an  image from any visible window on an X server and outputs it as an image
       file. You can capture a single window, the entire screen, or any  rectangular  portion  of
       the screen.

       mogrify  transforms  an  image  or  a  sequence  of images. These transforms include image
       scaling, image rotation, color reduction, and others. The transmogrified image  overwrites
       the original image.

       montage  creates a composite by combining several separate images. The images are tiled on
       the composite image with the name  of  the  image  optionally  appearing  just  below  the
       individual tile.

       time  executes  a  subcommand  and  reports  the  user,  system,  and total execution time
       consumed.

       version reports  the  GraphicsMagick  release  version,  maximum  sample-depth,  copyright
       notice, supported features, and the options used while building the software.

       The GraphicsMagick utilities recognize the following image formats:

       Name  Mode Description
        o  3FR       r-- Hasselblad Photo RAW
        o  8BIM      rw- Photoshop resource format
        o  8BIMTEXT  rw- Photoshop resource text format
        o  8BIMWTEXT rw- Photoshop resource wide text format
        o  APP1      rw- Raw application information
        o  APP1JPEG  rw- Raw JPEG binary data
        o  ART       r-- PF1: 1st Publisher
        o  ARW       r-- Sony Alpha DSLR RAW
        o  AVS       rw+ AVS X image
        o  BIE       rw- Joint Bi-level Image experts Group
                         interchange format
        o  BMP       rw+ Microsoft Windows bitmap image
        o  BMP2      -w- Microsoft Windows bitmap image v2
        o  BMP3      -w- Microsoft Windows bitmap image v3
        o  CACHE     --- Magick Persistent Cache image format
        o  CALS      rw- Continuous Acquisition and Life-cycle
                         Support Type 1 image
        o  CAPTION   r-- Caption (requires separate size info)
        o  CIN       rw- Kodak Cineon Format
        o  CMYK      rw- Raw cyan, magenta, yellow, and black
                         samples (8 or 16 bits, depending on
                         the image depth)
        o  CMYKA     rw- Raw cyan, magenta, yellow, black, and
                         matte samples (8 or 16 bits, depending
                         on the image depth)
        o  CR2       r-- Canon Photo RAW
        o  CRW       r-- Canon Photo RAW
        o  CUR       r-- Microsoft Cursor Icon
        o  CUT       r-- DR Halo
        o  DCM       r-- Digital Imaging and Communications in
                         Medicine image
        o  DCR       r-- Kodak Photo RAW
        o  DCX       rw+ ZSoft IBM PC multi-page Paintbrush
        o  DNG       r-- Adobe Digital Negative
        o  DPS       r-- Display PostScript Interpreter
        o  DPX       rw- Digital Moving Picture Exchange
        o  EPDF      rw- Encapsulated Portable Document Format
        o  EPI       rw- Adobe Encapsulated PostScript
                         Interchange format
        o  EPS       rw- Adobe Encapsulated PostScript
        o  EPS2      -w- Adobe Level II Encapsulated PostScript
        o  EPS3      -w- Adobe Level III Encapsulated PostScript
        o  EPSF      rw- Adobe Encapsulated PostScript
        o  EPSI      rw- Adobe Encapsulated PostScript
                         Interchange format
        o  EPT       rw- Adobe Encapsulated PostScript with MS-DOS
                         TIFF preview
        o  EPT2      rw- Adobe Level II Encapsulated PostScript
                         with MS-DOS TIFF preview
        o  EPT3      rw- Adobe Level III Encapsulated PostScript
                         with MS-DOS TIFF preview
        o  EXIF      rw- Exif digital camera binary data
        o  FAX       rw+ Group 3 FAX (Not TIFF Group3 FAX!)
        o  FITS      rw- Flexible Image Transport System
        o  FRACTAL   r-- Plasma fractal image
        o  FPX       rw- FlashPix Format
        o  GIF       rw+ CompuServe graphics interchange format
        o  GIF87     rw- CompuServe graphics interchange format
                         (version 87a)
        o  GRADIENT  r-- Gradual passing from one shade to
                         another
        o  GRAY      rw+ Raw gray samples (8/16/32 bits,
                         depending on the image depth)
        o  HISTOGRAM -w- Histogram of the image
        o  HRZ       r-- HRZ: Slow scan TV
        o  HTML      -w- Hypertext Markup Language and a
                         client-side image map
        o  ICB       rw+ Truevision Targa image
        o  ICC       rw- ICC Color Profile
        o  ICM       rw- ICC Color Profile
        o  ICO       r-- Microsoft icon
        o  ICON      r-- Microsoft icon
        o  IDENTITY  r-- Hald CLUT identity image
        o  IMAGE     r-- GraphicsMagick Embedded Image
        o  INFO      -w+ Image descriptive information and
                          statistics
        o  IPTC      rw- IPTC Newsphoto
        o  IPTCTEXT  rw- IPTC Newsphoto text format
        o  IPTCWTEXT rw- IPTC Newsphoto wide text format
        o  JBG       rw+ Joint Bi-level Image experts Group
                         interchange format
        o  JBIG      rw+ Joint Bi-level Image experts Group
                         interchange format
        o  JNG       rw- JPEG Network Graphics
        o  JP2       rw- JPEG-2000 JP2 File Format Syntax
        o  JPC       rw- JPEG-2000 Code Stream Syntax
        o  JPEG      rw- Joint Photographic Experts Group
                         JFIF format
        o  JPG       rw- Joint Photographic Experts Group
                         JFIF format
        o  K25       r-- Kodak Photo RAW
        o  KDC       r-- Kodak Photo RAW
        o  LABEL     r-- Text image format
        o  M2V       rw+ MPEG-2 Video Stream
        o  MAP       rw- Colormap intensities and indices
        o  MAT       r-- MATLAB image format
        o  MATTE     -w+ MATTE format
        o  MIFF      rw+ Magick Image File Format
        o  MNG       rw+ Multiple-image Network Graphics
        o  MONO      rw- Bi-level bitmap in least-significant-
                         -byte-first order
        o  MPC       rw+ Magick Persistent Cache image format
        o  MPEG      rw+ MPEG-1 Video Stream
        o  MPG       rw+ MPEG-1 Video Stream
        o  MRW       r-- Minolta Photo Raw
        o  MSL       r-- Magick Scripting Language
        o  MTV       rw+ MTV Raytracing image format
        o  MVG       rw- Magick Vector Graphics
        o  NEF       r-- Nikon Electronic Format
        o  NULL      r-- Constant image of uniform color
        o  OTB       rw- On-the-air bitmap
        o  P7        rw+ Xv thumbnail format
        o  PAL       rw- 16bit/pixel interleaved YUV
        o  PALM      rw- Palm Pixmap
        o  PBM       rw+ Portable bitmap format (black and white)
        o  PCD       rw- Photo CD
        o  PCDS      rw- Photo CD
        o  PCL       -w- Page Control Language
        o  PCT       rw- Apple Macintosh QuickDraw/PICT
        o  PCX       rw- ZSoft IBM PC Paintbrush
        o  PDB       rw+ Palm Database ImageViewer Format
        o  PDF       rw+ Portable Document Format
        o  PEF       r-- Pentax Electronic File
        o  PFA       r-- TrueType font
        o  PFB       r-- TrueType font
        o  PGM       rw+ Portable graymap format (gray scale)
        o  PGX       r-- JPEG-2000 VM Format
        o  PICON     rw- Personal Icon
        o  PICT      rw- Apple Macintosh QuickDraw/PICT
        o  PIX       r-- Alias/Wavefront RLE image format
        o  PLASMA    r-- Plasma fractal image
        o  PNG       rw- Portable Network Graphics
        o  PNG24     rw- Portable Network Graphics, 24 bit RGB
                         opaque only
        o  PNG32     rw- Portable Network Graphics, 32 bit RGBA
                         semitransparency OK
        o  PNG8      rw- Portable Network Graphics, 8-bit
                         indexed, binary transparency only
        o  PNM       rw+ Portable anymap
        o  PPM       rw+ Portable pixmap format (color)
        o  PREVIEW   -w- Show a preview an image enhancement,
                         effect, or f/x
        o  PS        rw+ Adobe PostScript
        o  PS2       -w+ Adobe Level II PostScript
        o  PS3       -w+ Adobe Level III PostScript
        o  PSD       rw- Adobe Photoshop bitmap
        o  PTIF      rw- Pyramid encoded TIFF
        o  PWP       r-- Seattle Film Works
        o  RAF       r-- Fuji Photo RAW
        o  RAS       rw+ SUN Rasterfile
        o  RGB       rw+ Raw red, green, and blue samples
        o  RGBA      rw+ Raw red, green, blue, and matte samples
        o  RLA       r-- Alias/Wavefront image
        o  RLE       r-- Utah Run length encoded image
        o  SCT       r-- Scitex HandShake
        o  SFW       r-- Seattle Film Works
        o  SGI       rw+ Irix RGB image
        o  SHTML     -w- Hypertext Markup Language and a
                         client-side image map
        o  STEGANO   r-- Steganographic image
        o  SUN       rw+ SUN Rasterfile
        o  SVG       rw+ Scalable Vector Gaphics
        o  TEXT      rw+ Raw text
        o  TGA       rw+ Truevision Targa image
        o  TIFF      rw+ Tagged Image File Format
        o  TILE      r-- Tile image with a texture
        o  TIM       r-- PSX TIM
        o  TOPOL     r-- TOPOL X Image
        o  TTF       r-- TrueType font
        o  TXT       rw+ Raw text
        o  UIL       -w- X-Motif UIL table
        o  UYVY      rw- 16bit/pixel interleaved YUV
        o  VDA       rw+ Truevision Targa image
        o  VICAR     rw- VICAR rasterfile format
        o  VID       rw+ Visual Image Directory
        o  VIFF      rw+ Khoros Visualization image
        o  VST       rw+ Truevision Targa image
        o  WBMP      rw- Wireless Bitmap (level 0) image
        o  WMF       r-- Windows Metafile
        o  WPG       r-- Word Perfect Graphics
        o  X         rw- X Image
        o  X3F       r-- Foveon X3 (Sigma/Polaroid) RAW
        o  XBM       rw- X Windows system bitmap (black
                         and white)
        o  XC        r-- Constant image uniform color
        o  XCF       r-- GIMP image
        o  XMP       rw- Adobe XML metadata
        o  XPM       rw- X Windows system pixmap (color)
        o  XV        rw+ Khoros Visualization image
        o  XWD       rw- X Windows system window dump (color)
        o  YUV       rw- CCIR 601 4:1:1 or 4:2:2 (8-bit only)

           Modes:
                     r   Read
                     w   Write
                     +   Multi-image

       Support for some of these formats require additional programs or libraries.  See README in
       the source package for where to find optional additional software.

       Note, a format delineated with + means that if more than one image  is  specified,  frames
       are  combined  into  a  single  multi-image  file.  Use +adjoin if you want a single image
       produced for each frame.

       Your installation might not support all of the formats in the list.  To  get  an  accurate
       listing  of  the formats supported by your particular configuration, run "gm convert -list
       format".

       Raw images are expected to have one byte per pixel unless gm is compiled in 16-bit quantum
       mode  or  in  32-bit quantum mode. Here, the raw data is expected to be stored two or four
       bytes per pixel, respectively, in most-significant-byte-first order.  For example, you can
       tell  if  gm  was  compiled in 16-bit mode by typing "gm version" without any options, and
       looking for "Q:16" in the first line of output.

FILES AND FORMATS

       By default, the image format is determined by its magic number, i.e., the first few  bytes
       of  the  file.  To  specify  a particular image format, precede the filename with an image
       format name and a colon (i.e.ps:image) or specify the image type as  the  filename  suffix
       (i.e.image.ps).  The magic number takes precedence over the filename suffix and the prefix
       takes precedence over the magic number and the suffix in input  files.   When  a  file  is
       read,  its  magic  number  is  stored in the "image->magick" string.  In output files, the
       prefix takes precedence over the filename suffix, and the filename suffix takes precedence
       over the "image->magick" string.

       To read the "built-in" formats (GRANITE, H, LOGO, NETSCAPE, PLASMA, and ROSE) use a prefix
       (including the colon) without a filename or suffix.  To read the  XC  format,  follow  the
       colon  with  a  color  specification.  To read the CAPTION format, follow the colon with a
       text string or with a filename prefixed with the at symbol (@).

       When you specify X as your image type, the filename has special meaning. It specifies an X
       window  by  id,  name,  or  root.  If  no filename is specified, the window is selected by
       clicking the mouse in the desired window.

       Specify input_file as - for standard input, output_file as  -  for  standard  output.   If
       input_file has the extension .Z or .gz, the file is uncompressed with uncompress or gunzip
       respectively.  If output_file has the extension .Z or .gz, the file  is  compressed  using
       with compress or gzip respectively.

       Use  an  optional index enclosed in brackets after an input file name to specify a desired
       subimage of a multi-resolution image format like Photo CD  (e.g.  "img0001.pcd[4]")  or  a
       range  for MPEG images (e.g. "video.mpg[50-75]"). A subimage specification can be disjoint
       (e.g. "image.tiff[2,7,4]"). For raw images, specify a subimage with a geometry (e.g. -size
       640x512  "image.rgb[320x256+50+50]").   Surround  the  image  name with quotation marks to
       prevent your shell from interpreting the square brackets. Single images are  written  with
       the  filename  you  specify.  However,  multi-part  images  (e.g., a multi-page PostScript
       document with +adjoin specified) may be written with the scene number included as part  of
       the  filename.  In  order  to include the scene number in the filename, it is necessary to
       include a printf-style %d format specification in  the  file  name  and  use  the  +adjoin
       option. For example,

           image%02d.miff

       writes  files  image00.miff,  image01.miff,  etc.  Only  a single specification is allowed
       within an output filename. If more than one specification is present, it will be  ignored.
       It  is  best  to  embed  the  scene  number  in the base part of the file name, not in the
       extension, because the extension will not be a recognizeable image type.

       When running a commandline utility, you can prepend an at sign @ to a filename to  read  a
       list  of image filenames from that file. This is convenient in the event you have too many
       image filenames to fit on the command line.

OPTIONS

       Options are processed in command line order. Any option you specify on  the  command  line
       remains  in  effect for the set of images that follows, until the set is terminated by the
       appearance of any option or -noop.  Some options only affect the decoding  of  images  and
       others only the encoding.  The latter can appear after the final group of input images.

       This  is  a combined list of the command-line options used by the GraphicsMagick utilities
       (animate, compare, composite, convert, display, identify, import, mogrify and montage).

       In this document, angle brackets  ("<>")  enclose  variables  and  curly  brackets  ("{}")
       enclose  optional  parameters.  For  example,  "-fuzz <distance>{%}" means you can use the
       option "-fuzz 10" or "-fuzz 2%".

       -adjoin
              join images into a single multi-image file

              By default, all images of an image sequence are stored in the same  file.  However,
              some  formats  (e.g.  JPEG) do not support storing more than one image per file and
              only the first frame in an image sequence will be saved unless the result is  saved
              to separate files. Use +adjoin to force saving multiple frames to multiple numbered
              files. If +adjoin is used, then the output filename must  include  a  printf  style
              formatting specification for the numeric part of the filename.  For example,

                  image%02d.miff

       -affine <matrix>
              drawing transform matrix

              This  option  provides a transform matrix {sx,rx,ry,sy,tx,ty} for use by subsequent
              -draw or -transform options.

       -antialias
              remove pixel aliasing

              By default antialiasing algorithms are used when drawing objects  (e.g.  lines)  or
              rendering  vector  formats (e.g. WMF and Postscript). Use +antialias to disable use
              of antialiasing  algorithms.  Reasons  to  disable  antialiasing  include  avoiding
              increasing colors in the image, or improving rendering speed.

       -append
              append a set of images

              This option creates a single image where the images in the original set are stacked
              top-to-bottom.  If they are not of the  same  width,  any  narrow  images  will  be
              expanded  to  fit using the background color.  Use +append to stack images left-to-
              right.  The set of images is terminated by the appearance of any  option.   If  the
              -append option appears after all of the input images, all images are appended.

       -asc-cdl <spec>
              apply ASC CDL color transform

              Applies  ("bakes  in")  the  ASC  CDL,  which is a format for the exchange of basic
              primary color grading information between equipment  and  software  from  different
              manufacturers.  The  format defines the math for three functions: slope, offset and
              power. Each function uses a number for the red, green, and blue color channels  for
              a  total  of  nine  numbers  comprising  a  single color decision. The tenth number
              (optional) is for chromiance (saturation) as specified by ASC CDL 1.2.

              The argument string is comma delimited and is in the following  form  (but  without
              invervening spaces or line breaks)

                  redslope,redoffset,redpower:
                  greenslope,greenoffset,greenpower:
                  blueslope,blueoffset,bluepower:
                  saturation

              with the unity (no change) specification being:

                  "1.0,0.0,1.0:1.0,0.0,1.0:1.0,0.0,1.0:1.0"

       -authenticate <string>
              decrypt image with this password

              Use  this option to supply a password for decrypting an image or an image sequence,
              if it is being read from a format such as PDF that supports encryption.  Encrypting
              images being written is not supported.

       -auto-orient
              orient (rotate) image so it is upright

              Adjusts  the  image  orienation  so  that  it  is  suitable  for viewing.  Uses the
              orientation tag obtained from the image file or as supplied by the -orient option.

       -average
              average a set of images

              The set of images is terminated by the appearance of any option.  If  the  -average
              option appears after all of the input images, all images are averaged.

       -backdrop
              display the image centered on a backdrop.

              This backdrop covers the entire workstation screen and is useful for hiding other X
              window activity while viewing the image. The color of the backdrop is specified  as
              the  foreground  color  (X11 default is black).  Refer to "X Resources", below, for
              details.

       -background <color>
              the background color

              The color is specified using the format described under the -fill option.

       -black-threshold red[,green][,blue][,opacity]
              pixels below the threshold become black

              Use -black-threshold to set pixels with values below  the  specified  threshold  to
              minimum  value  (black). If only one value is supplied, or the red, green, and blue
              values are identical, then intensity thresholding is used. If the  color  threshold
              values  are  not  identical  then  channel-based  thresholding  is  used, and color
              distortion will occur. Specify a negative value (e.g. -1) if you want a channel  to
              be  ignored  but you do want to threshold a channel later in the list. If a percent
              (%) symbol is appended, then the values are treated  as  a  percentage  of  maximum
              range.

       -blue-primary <x>,<y>
              blue chromaticity primary point

       -blur <radius>{x<sigma>}
              blur the image with a Gaussian operator

              Blur with the given radius and standard deviation (sigma).

       -border <width>x<height>
              surround the image with a border of color

              See -geometry for details about the geometry specification.

       -bordercolor <color>
              the border color

              The color is specified using the format described under the -fill option.

       -borderwidth <geometry>
              the border width

       -box <color>
              set the color of the annotation bounding box

              The color is specified using the format described under the -fill option.

              See -draw for further details.

       -channel <type>
              the type of channel

              Choose  from:  Red,  Green,  Blue, Opacity, Matte, Cyan, Magenta, Yellow, Black, or
              Gray.

              Use this option to extract a particular  channel  from  the  image.   Opacity,  for
              example, is useful for extracting the opacity values from an image.

       -charcoal <factor>
              simulate a charcoal drawing

       -chop <width>x<height>{+-}<x>{+-}<y>{%}
              remove pixels from the interior of an image

              Width  and  height  give  the number of columns and rows to remove, and x and y are
              offsets that give the location of the leftmost column and topmost row to remove.

              The x offset normally specifies the leftmost column to  remove.   If  the  -gravity
              option is present with NorthEast, East, or SouthEast gravity, it gives the distance
              leftward from the right edge of the  image  to  the  rightmost  column  to  remove.
              Similarly,  the  y  offset normally specifies the topmost row to remove, but if the
              -gravity option  is  present  with  SouthWest,  South,  or  SouthEast  gravity,  it
              specifies  the  distance upward from the bottom edge of the image to the bottom row
              to remove.

              The -chop option removes entire rows and columns, and moves  the  remaining  corner
              blocks leftward and upward to close the gaps.

       -clip  apply the clipping path, if one is present

              If a clipping path is present, it will be applied to subsequent operations.

              For example, if you type the following command:

                  gm convert -clip -negate cockatoo.tif negated.tif

              only the pixels within the clipping path are negated.

              The -clip feature requires the XML library.  If the XML library is not present, the
              option is ignored.

       -coalesce
              merge a sequence of images

              Each image N in the sequence after Image 0 is replaced with the  image  created  by
              flattening images 0 through N.

              The  set of images is terminated by the appearance of any option.  If the -coalesce
              option appears after all of the input images, all images are coalesced.

       -colorize <value>
              colorize the image with the pen color

              Specify the amount  of  colorization  as  a  percentage.  You  can  apply  separate
              colorization  values  to  the  red,  green,  and  blue channels of the image with a
              colorization value list delimited with slashes (e.g. 0/0/50).

              The -colorize option may be used in conjunction with -modulate to  produce  a  nice
              sepia toned image like:

                  gm convert input.ppm -modulate 115,0,100 \
                            -colorize 7,21,50 output.ppm.

       -colormap <type>
              define the colormap type

              Choose between shared or private.

              This  option  only  applies  when  the  default  X  server visual is PseudoColor or
              GRAYScale. Refer to -visual for more details. By  default,  a  shared  colormap  is
              allocated.  The  image shares colors with other X clients.  Some image colors could
              be approximated, therefore your image may look very different than intended. Choose
              Private  and  the  image  colors appear exactly as they are defined. However, other
              clients may go technicolor when the image colormap is installed.

       -colors <value>
              preferred number of colors in the image

              The actual number of colors in the image may be less than your request,  but  never
              more.  Note,  this is a color reduction option. Images with less unique colors than
              specified with this option will have any duplicate or unused  colors  removed.  The
              ordering of an existing color palette may be altered. When converting an image from
              color to grayscale, convert the image to the gray colorspace  before  reducing  the
              number   of   colors   since   doing   so   is   most   efficient.   Refer   to  <a
              href="quantize.html">quantize for more details.

              Note, options -dither, -colorspace,  and  -treedepth  affect  the  color  reduction
              algorithm.

       -colorspace <value>
              the type of colorspace

              Choices  are:  CineonLog,  CMYK, GRAY, HSL, HWB, OHTA, RGB, Rec601Luma, Rec709Luma,
              Rec601YCbCr, Rec709YCbCr, Transparent, XYZ, YCbCr, YIQ, YPbPr, or YUV.

              Color reduction, by default, takes place in the RGB color space. Empirical evidence
              suggests that distances in color spaces such as YUV or YIQ correspond to perceptual
              color differences more closely than do distances in RGB space.  These color  spaces
              may  give  better results when color reducing an image.  Refer to quantize for more
              details.  Two gray colorspaces are supported. The Rec601Luma space is based on  the
              recommendations  for legacy NTSC television (ITU-R BT.601-5).  The Rec709Luma space
              is based on the recommendations for HDTV (Rec. ITU-R BT.709-5) and is suitable  for
              use  with computer graphics, and for contemporary CRT displays. The GRAY colorspace
              currently selects the Rec601Luma colorspace by  default  for  backwards  compatibly
              reasons. This default may be re-considered in the future.

              Two  YCbCr  colorspaces  are  supported.  The  Rec601YCbCr  space  is  based on the
              recommendations for legacy NTSC television (ITU-R BT.601-5). The  Rec709CbCr  space
              is based on the recommendations for HDTV (Rec.  ITU-R BT.709-5) and is suitable for
              suitable for use with computer graphics, and for  contemporary  CRT  displays.  The
              YCbCr colorspace specification is equivalent toRec601YCbCr.

              The Transparent color space behaves uniquely in that it preserves the matte channel
              of the image if it exists.

              The -colors or -monochrome option, or saving to a file format which requires  color
              reduction, is required for this option to take effect.

       -comment <string>
              annotate an image with a comment

              Use this option to assign a specific comment to the image, when writing to an image
              format that supports comments. You can include the  image  filename,  type,  width,
              height,  or  other  image  attribute  by embedding special format characters listed
              under the -format option.  The comment is not drawn on the image, but  is  embedded
              in  the image datastream via a "Comment" tag or similar mechanism.  If you want the
              comment to be visible on the image itself, use the -draw option instead.

              For example,

                   -comment "%m:%f %wx%h"

              produces an image comment of MIFF:bird.miff 512x480 for an image  titled  bird.miff
              and whose width is 512 and height is 480.

              If the first character of string is @, the image comment is read from a file titled
              by the remaining characters in the string.  Please note that if  the  string  comes
              from an untrusted source that it should be sanitized before use since otherwise the
              content of an arbitrary readable file could be incorporated in  a  comment  in  the
              output file (a security risk).

              If the -comment option appears multiple times, only the last comment is stored.

              In  PNG  images,  the  comment  is  stored in a tEXt or zTXt chunk with the keyword
              "comment".

       -compose <operator>
              the type of image composition

              The description of composition uses abstract terminology in order to allow the  the
              description  to be more clear, while avoiding constant values which are specific to
              a particular build configuration. Each image pixel is represented  by  red,  green,
              and  blue levels (which are equal for a gray pixel). MaxRGB is the maximum integral
              value which may be stored in the red, green, or blue channels of  the  image.  Each
              image  pixel  may  also  optionally (if the image matte channel is enabled) have an
              associated level of opacity (ranging from opaque to transparent), which may be used
              to  determine  the  influence  of  the  pixel color when compositing the pixel with
              another image pixel. If the image matte channel is disabled, then all pixels in the
              image  are  treated as opaque.  The color of an opaque pixel is fully visible while
              the color of a transparent pixel color is entirely absent (pixel color is ignored).

              By definition, raster images have a rectangular shape. All image rows are of  equal
              length, and all image columns have the same number of rows. By treating the opacity
              channel as a visual "mask" the rectangular image may be given a "shape" by treating
              the  opacity  channel as a cookie-cutter for the image. Pixels within the shape are
              opaque, while pixels outside the shape are transparent. Pixels on the  boundary  of
              the  shape  may  be between opaque and transparent in order to provide antialiasing
              (visually smooth edges). The description of  the  composition  operators  use  this
              concept  of  image "shape" in order to make the description of the operators easier
              to understand. While it is  convenient  to  describe  the  operators  in  terms  of
              "shapes" they are by no means limited to mask-style operations since they are based
              on continuous floating-point mathematics rather than simple boolean operations.

              By default, the Over composite operator is used. The following composite  operators
              are available:

                   Over
                   In
                   Out
                   Atop
                   Xor
                   Plus
                   Minus
                   Add
                   Subtract
                   Difference
                   Divide
                   Multiply
                   Bumpmap
                   Copy
                   CopyRed
                   CopyGreen
                   CopyBlue
                   CopyOpacity
                   CopyCyan
                   CopyMagenta
                   CopyYellow
                   CopyBlack

              The behavior of each operator is described below.

               Over

                    The  result  will  be the union of the two image shapes, with opaque areas of
                    change-image obscuring base-image in the region of overlap.

               In

                    The result is simply change-image cut by the shape of base-image. None of the
                    image data of base-image will be in the result.

               Out

                    The resulting image is change-image with the shape of base-image cut out.

               Atop

                    The result is the same shape as base-image, with change-image obscuring base-
                    image where the image shapes overlap. Note this differs from over because the
                    portion  of  change-image  outside  base-image's shape does not appear in the
                    result.

               Xor

                    The result is the image data from both change-image and  base-image  that  is
                    outside the overlap region. The overlap region will be blank.

               Plus

                    The  result  is  just the sum of the image data. Output values are cropped to
                    MaxRGB (no overflow). This operation is independent of the matte channels.

               Minus

                    The result of change-image - base-image, with underflow cropped to zero.  The
                    matte channel is ignored (set to opaque, full coverage).

               Add

                    The  result  of change-image + base-image, with overflow wrapping around (mod
                    MaxRGB+1).

               Subtract

                    The result of change-image - base-image, with underflow wrapping around  (mod
                    MaxRGB+1).  The  add and subtract operators can be used to perform reversible
                    transformations.

               Difference

                    The result of abs(change-image - base-image). This is  useful  for  comparing
                    two very similar images.

               Divide

                    The  result  of  change-image  / base-image. This is useful for improving the
                    readability of text on unevenly  illuminated  photos  (by  using  a  gaussian
                    blurred copy of change-image as base-image).

               Multiply

                    The  result  of change-image * base-image. This is useful for the creation of
                    drop-shadows.

               Bumpmap

                    The result base-image shaded by change-image.

               Copy

                    The resulting image is base-image replaced with change-image. Here the  matte
                    information is ignored.

               CopyRed

                    The  resulting  image  is the red channel in base-image replaced with the red
                    channel in change-image. The other channels are copied untouched.

               CopyGreen

                    The resulting image is the green channel  in  base-image  replaced  with  the
                    green channel in change-image. The other channels are copied untouched.

               CopyBlue

                    The  resulting image is the blue channel in base-image replaced with the blue
                    channel in change-image. The other channels are copied untouched.

               CopyOpacity

                    The resulting image is the opacity channel in base-image  replaced  with  the
                    opacity channel in change-image. The other channels are copied untouched.

               CopyCyan

                    The  resulting image is the cyan channel in base-image replaced with the cyan
                    channel in change-image. The other channels are copied untouched. Use of this
                    operator requires that base-image be in CMYK(A) colorspace.

               CopyMagenta

                    The  resulting  image  is the magenta channel in base-image replaced with the
                    magenta channel in change-image. The other channels are copied untouched. Use
                    of this operator requires that base-image be in CMYK(A) colorspace.

               CopyYellow

                    The  resulting  image  is  the yellow channel in base-image replaced with the
                    yellow channel in change-image. The other channels are copied untouched.  Use
                    of this operator requires that base-image be in CMYK(A) colorspace.

               CopyBlack

                    The  resulting  image  is  the  black channel in base-image replaced with the
                    black channel in change-image. The other channels are copied  untouched.  Use
                    of  this  operator  requires  that  base-image  be  in CMYK(A) colorspace. If
                    change-image is not in CMYK space, then the  change-image  pixel  intensities
                    are used.

       -compress <type>
              the type of image compression

              Choices  are: None, BZip, Fax, Group3, Group4, JPEG, Lossless, LZW, RLE, Zip, LZMA,
              JPEG2000, JPEG2000, JBIG, JBIG2, WebP, or ZSTD.

              Specify +compress to store the binary image in an uncompressed format.  The default
              is the compression type of the specified image file.

              "Lossless" refers to lossless JPEG, which is only available if the JPEG library has
              been patched to support it. Use of lossless JPEG is generally not recommended.

              Use the -quality option to set the compression  level  to  be  used  by  the  JPEG,
              JPEG-2000,  PNG,  MIFF, MPEG, and TIFF encoders. Use the -sampling-factor option to
              set the sampling factor to be used by the DPX, JPEG, MPEG,  and  YUV  encoders  for
              downsampling the chroma channels.

       -contrast
              enhance or reduce the image contrast

              This  option  enhances  the  intensity  differences  between the lighter and darker
              elements of the image. Use -contrast to enhance the image or  +contrast  to  reduce
              the image contrast.

              For a more pronounced effect you can repeat the option:

                  gm convert rose: -contrast -contrast rose_c2.png

       -convolve <kernel>
              convolve image with the specified convolution kernel

              The kernel is specified as a comma-separated list of floating point values, ordered
              left-to right, starting with the top row. The order of the kernel is determined  by
              the  square  root  of  the  number  of  entries.  Presently only square kernels are
              supported.

       -create-directories
              create output directory if required

              Use this option with -output-directory if the input  paths  contain  subdirectories
              and  it  is  desired  to  create  similar  subdirectories  in the output directory.
              Without this option, mogrify will fail if the required output  directory  does  not
              exist.

       -crop <width>x<height>{+-}<x>{+-}<y>{%}
              preferred size and location of the cropped image

              See -geometry for details about the geometry specification.

              The  width and height give the size of the image that remains after cropping, and x
              and y are offsets that give the location of the top  left  corner  of  the  cropped
              image with respect to the original image.  To specify the amount to be removed, use
              -shave instead.

              If the x and y offsets are present, a single image is generated, consisting of  the
              pixels  from  the  cropping  region.  The offsets specify the location of the upper
              left corner of the cropping region measured downward and rightward with respect  to
              the  upper  left  corner  of  the  image.   If  the -gravity option is present with
              NorthEast, East, or SouthEast gravity, it gives  the  distance  leftward  from  the
              right  edge  of  the image to the right edge of the cropping region.  Similarly, if
              the -gravity option is present with SouthWest, South,  or  SouthEast  gravity,  the
              distance is measured upward between the bottom edges.

              If  the  x  and  y  offsets  are omitted, a set of tiles of the specified geometry,
              covering the entire input image, is generated.  The rightmost tiles and the  bottom
              tiles  are  smaller  if the specified geometry extends beyond the dimensions of the
              input image.

       -cycle <amount>
              displace image colormap by amount

              Amount defines the number of positions each colormap entry isshifted.

       -debug <events>
              enable debug printout

              The events parameter specifies which events are to be logged.   It  can  be  either
              None,  All,  or  a  comma-separated list consisting of one or more of the following
              domains: Annotate, Blob, Cache,  Coder,  Configure,  Deprecate,  Error,  Exception,
              FatalError,   Information,   Locale,   Option,   Render,  Resource,  TemporaryFile,
              Transform, User.  Warning, or X11, For example, to log cache and blob events, use

                  gm convert -debug "Cache,Blob" rose: rose.png

              The "User" domain is normally empty, but developers can log "User" events in  their
              private copy of GraphicsMagick.

              Use the -log option to specify the format for debugging output.

              Use +debug to turn off all logging.

              An alternative to using -debug is to use the MAGICK_DEBUG environment variable. The
              allowed values for the MAGICK_DEBUG environment variable are the same  as  for  the
              -debug option.

       -deconstruct
              break down an image sequence into constituent parts

              This option compares each image with the next in a sequence and returns the maximum
              bounding region of any pixel differences it discovers.   This  method  can  undo  a
              coalesced  sequence  returned  by  the -coalesce option, and is useful for removing
              redundant information from a GIF or MNG animation.

              The sequence of images is terminated by the  appearance  of  any  option.   If  the
              -deconstruct  option  appears  after  all  of  the  input  images,  all  images are
              deconstructed.

       -define <key>{=<value>},...
              add coder/decoder specific options This option creates one or more definitions  for
              coders and decoders to use while reading and writing image data. Definitions may be
              passed to coders and decoders to control options that are specific to certain image
              formats. If value is missing for a definition, an empty-valued definition of a flag
              will be created with that name. This is used to control on/off options. Use +define
              <key>,...  to  remove definitions previously created. Use +define "*" to remove all
              existing definitions.

              The following definitions may be created:

               cineon:colorspace={rgb|cineonlog}

                    Use the cineon:colorspace option when reading a Cineon file  to  specify  the
                    colorspace  the  Cineon file uses. This overrides the colorspace type implied
                    by the DPX header (if any).

               dpx:bits-per-sample=<value>

                    If the dpx:bits-per-sample key is  defined,  GraphicsMagick  will  write  DPX
                    images  with  the  specified  bits  per sample, overriding any existing depth
                    value. If this option is not specified,  then  the  value  is  based  on  the
                    existing  image  depth  value  from the original image file. The DPX standard
                    supports bits per sample values of 1, 8, 10, 12, and  16.  Many  DPX  readers
                    demand a sample size of 10 bits with type A padding (see below).

               dpx:colorspace={rgb|cineonlog}

                    Use  the  dpx:colorspace  option  when  reading  a  DPX  file  to specify the
                    colorspace the DPX file uses. This overrides the colorspace type  implied  by
                    the DPX header (if any).

               dpx:packing-method={packed|a|b|lsbpad|msbpad}

                    DPX  samples  are output within 32-bit words. They may be tightly packed end-
                    to-end within the words ("packed"), padded with null bits to the right of the
                    sample  ("a" or "lsbpad"), or padded with null bits to the left of the sample
                    ("b" or "msbpad"). This option only has an effect for sample sizes of  10  or
                    12  bits.  If  samples  are  not  packed,  the DPX standard recommends type A
                    padding. Many DPX readers demand a  sample  size  of  10  bits  with  type  A
                    padding.

               dpx:pixel-endian={lsb|msb}

                    Allows  the  user  to  specify the endian order of the pixels when reading or
                    writing the DPX files. Sometimes this is useful if the file is (or  must  be)
                    written  incorrectly  so  that  the  file header and the pixels use different
                    endianness.

               dpx:swap-samples={true|false}

               dpx:swap-samples-read={true|false}

               dpx:swap-samples-write={true|false}

                    GraphicsMagick strives to adhere to the DPX standard but certain  aspects  of
                    the  standard can be quite confusing. As a result, some 10-bit DPX files have
                    Red and Blue interchanged, or Cb and Cr  interchanged  due  to  an  different
                    interpretation  of  the  standard,  or  getting  the wires crossed. The swap-
                    samples option may be supplied when reading or writing in order  to  read  or
                    write  using the necessary sample order.  Use swap-samples-read when swapping
                    should only occur in the reader, or swap-samples-write when  swapping  should
                    only occur in the writer.

               gradient:direction={South|North|West|East|NorthWest|NorthEast|SouthWest|SouthEast}

                    By  default,  the  gradient  coder  produces  a  gradient  from top to bottom
                    ("South").  Since  GraphicsMagick  1.3.35,  the  gradient  direction  may  be
                    specified   to   produce   gradient   vectors  according  to  a  gravity-like
                    specification.  The arguments are South (Top to  Bottom),  North  (Bottom  to
                    Top),  West (Right to Left), East (Left to Right), NorthWest (Bottom-Right to
                    Top-Left), NorthEast (Bottom-Left to Top-Right), SouthWest (Top-Right Bottom-
                    Left), and SouthEast (Top-Left to Bottom-Right).

               jp2:rate=<value>

                    Specify  the  compression  factor  to  use while writing JPEG-2000 files. The
                    compression factor is the reciprocal of  the  compression  ratio.  The  valid
                    range  is  0.0  to 1.0, with 1.0 indicating lossless compression. If defined,
                    this value overrides the -quality setting. The default quality setting of  75
                    results in a rate value of 0.06641.

               jpeg:block-smoothing={true|false}

                    Enables  or  disables  block  smoothing  when  reading  a  JPEG file (default
                    enabled).

               jpeg:dct-method=<value>

                    Selects the  IJG  JPEG  library  DCT  implementation  to  use.  The  encoding
                    implementations  vary  in speed and encoding error. The available choices for
                    value are islow, ifast, float, default and fastest. Note that  fastest  might
                    not  necessarily  be  fastest on your CPU, depending on the choices made when
                    the JPEG library was built and how your CPU behaves.

               jpeg:fancy-upsampling={true|false}

                    Enables or disables fancy  upsampling  when  reading  a  JPEG  file  (default
                    enabled).

               jpeg:max-scan-number=<value>

                    Specifies  an  integer  value  for  the  maximum  number of progressive scans
                    allowed in a JPEG file.  The default maximum is 100  scans.   This  limit  is
                    imposed  due to a weakness in the JPEG standard which allows small JPEG files
                    to take many minutes or hours to be read.

               jpeg:max-warnings=<value>

                    Specifies an integer value for how many warnings are allowed  for  any  given
                    error  type  before  being  promoted  to  a hard error.  JPEG files producing
                    excessive warnings indicate a problem with the file.

               jpeg:optimize-coding={true|false}

                    Selects if huffman encoding should be used. Huffman encoding  is  enabled  by
                    default, but may be disabled for very large images since it encoding requires
                    that the entire image  be  buffered  in  memory.  Huffman  encoding  produces
                    smaller  JPEG  files  at  the  expense  of  added compression time and memory
                    consumption.

               jpeg:preserve-settings

                    If the jpeg:preserve-settings flag is defined, the JPEG encoder will use  the
                    same  "quality"  and  "sampling-factor" settings that were found in the input
                    file, if the input was in JPEG format. These settings are also  preserved  if
                    the  input is a JPEG file and the output is a JNG file.  If the colorspace of
                    the output file differs from that of the input file, the quality  setting  is
                    preserved but the sampling-factors are not.

               pcl:fit-to-page

                    If  the  pcl:fit-to-page  flag  is  defined, then the printer is requested to
                    scale the image to fit the page size (width and/or height).
               png:chunk-malloc-max=<value>

                    png:chunk-malloc-max specifies the maximum chunk size  that  libpng  will  be
                    allowed  to read.  Libpng's default is normally 8,000,000 bytes. Very rarely,
                    a valid PNG file may be encountered where the error is reported  "chunk  data
                    is  too  large".  In this case, the limit may be increased using this option.
                    Take care when increasing this limit since an excessively large  limit  could
                    allow untrusted files to use excessive memory.

               mng:maximum-loops=<value>

                    mng:maximum-loops  specifies  the  maximum  number  of  loops  allowed  to be
                    specified by a MNG LOOP chunk. Without an imposed limit,  a  MNG  file  could
                    request  up  to  2147483647 loops, which could run for a very long time.  The
                    current default limit is 512 loops.

               pdf:use-cropbox={true|false}

                    If the pdf:use-cropbox flag is set to true, then Ghostscript is requested  to
                    apply the PDF crop box.

               pdf:stop-on-error={true|false}

                    If  the  pdf:stop-on-error flag is set to true, then Ghostscript is requested
                    to stop processing the PDF when the first error is encountered.  Otherwise it
                    will attempt to process all requested pages.

               ps:imagemask

                    If  the  ps:imagemask  flag  is  defined, the PS3 and EPS3 coders will create
                    Postscript files that render bilevel images  with  the  Postscript  imagemask
                    operator instead of the image operator.

               ptif:minimum-geometry=<geometry>

                    If  the  ptif:minimum-geometry  key is defined, GraphicsMagick will use it to
                    determine the minimum frame size to output when writing a pyramid  TIFF  file
                    (a TIFF file containing a succession of reduced versions of the first frame).
                    The default minimum geometry is 32x32.

               tiff:alpha={unspecified|associated|unassociated}

                    Specify the TIFF alpha channel type  when  reading  or  writing  TIFF  files,
                    overriding  the normal value. The default alpha channel type for new files is
                    unspecified alpha. Existing alpha settings are preserved when converting from
                    one  TIFF  file to another. When a TIFF file uses associated alpha, the image
                    pixels are pre-multiplied (i.e. altered) with the alpha channel.  Files  with
                    "associated"  alpha  appear  as  if  they  were  alpha  composited on a black
                    background when the matte channel is disabled. If the unassociated alpha type
                    is  selected,  then  the  alpha channel is saved without altering the pixels.
                    Photoshop recognizes associated alpha as  transparency  information,  if  the
                    file  is saved with unassociated alpha, the alpha information is loaded as an
                    independent  channel.   Note   that   for   many   years,   ImageMagick   and
                    GraphicsMagick  marked TIFF files as using associated alpha, without properly
                    pre-multiplying the pixels.

               tiff:fill-order={msb2lsb|lsb2msb}

                    If the  tiff:fill-order  key  is  defined,  GraphicsMagick  will  use  it  to
                    determine  the  bit  fill  order  used  while  writing TIFF files. The normal
                    default is "msb2lsb", which matches the native bit order of all modern  CPUs.
                    The  only  exception  to  this  is  when  Group3 or Group4 FAX compression is
                    requested since FAX machines send data in bit-reversed  order  and  therefore
                    RFC 2301 recommends using reverse order.

               tiff:group-three-options=<value>

                    If the tiff:group-three-options key is defined, GraphicsMagick will use it to
                    set the group3 options tag when writing group3-compressed TIFF.   Please  see
                    the TIFF specification for the usage of this tag.  The default value is 4.

               tiff:ignore-tags=<tags>

                    If  the  tiff:ignore-tags key is defined, then it is used as a list of comma-
                    delimited integer TIFF tag values to ignore  while  reading  the  TIFF  file.
                    This  is  useful in order to be able to read files which which otherwise fail
                    to read due to problems with  TIFF  tags.   Note  that  some  TIFF  tags  are
                    required in order to be able to read the image data at all.

               tiff:report-warnings={false|true}

                    If  the  tiff:report-warnings  key  is  defined  and  set  to true, then TIFF
                    warnings are reported as a warning exception  rather  than  as  a  coder  log
                    message.   Such  warnings  are  reported  after  the  image  has been read or
                    written.  Most TIFF warnings are benign but sometimes they  may  help  deduce
                    problems  with  the  TIFF  file, or help detect that the TIFF file requires a
                    special application to read successfully due to the  use  of  proprietary  or
                    specialized extensions.

               tiff:sample-format={unsigned|ieeefp}

                    If  the  tiff:sample-format  key  is  defined,  GraphicsMagick will use it to
                    determine the sample format used while writing TIFF  files.  The  default  is
                    "unsigned". Specify "ieeefp" in order to write floating-point TIFF files with
                    float (32-bit) or double (64-bit) values. Use the tiff:bits-per-sample define
                    to determine the type of floating-point value to use.

               tiff:max-sample-value=<value>

                    If  the  tiff:max-sample-value  key  is  defined, GraphicsMagick will use the
                    assigned value as the maximum floating point value while reading  or  writing
                    IEEE  floating  point  TIFFs. Otherwise the maximum value is 1.0 or the value
                    obtained from the file's SMaxSampleValue tag (if present). The floating point
                    data  is  currently not scanned in advance to determine a best maximum sample
                    value so if the range is not 1.0, or the SMaxSampleValue tag is not  present,
                    it  may be necessary to (intelligently) use this parameter to properly read a
                    file.

               tiff:min-sample-value=<value>

                    If the tiff:min-sample-value key is  defined,  GraphicsMagick  will  use  the
                    assigned  value  as the minimum floating point value while reading or writing
                    IEEE floating point TIFFs. Otherwise the minimum value is 0.0  or  the  value
                    obtained from the file's SMinSampleValue tag (if present).

               tiff:bits-per-sample=<value>

                    If  the tiff:bits-per-sample key is defined, GraphicsMagick will write images
                    with the specified bits per sample,  overriding  any  existing  depth  value.
                    Value  may  be any in the range of 1 to 32, or 64 when the default ´unsigned'
                    format is written, or 16/32/24/64 if IEEEFP format is written.   Please  note
                    that  the  baseline  TIFF  6.0  specification only requires readers to handle
                    certain powers of two, and the values to be handled depend on the  nature  of
                    the image (e.g. colormapped, grayscale, RGB, CMYK).

               tiff:samples-per-pixel=<value>

                    If  the tiff:samples-per-pixel key is defined to a value, the TIFF coder will
                    write TIFF images with the defined samples per pixel,  overriding  any  value
                    stored in the image. This option should not normally be used.

               tiff:rows-per-strip=<value>

                    Allows  the user to specify the number of rows per TIFF strip.  Rounded up to
                    a multiple of 16 when using JPEG compression. Ignored when using tiles.

               tiff:strip-per-page=true

                    Requests that the image is written in a single TIFF strip. This  is  normally
                    the  default when group3 or group4 compression is requested within reasonable
                    limits. Requesting a single strip for large images may result in failure  due
                    to resource consumption in the writer or reader.

               tiff:tile

                    Enable writing tiled TIFF (rather than stripped) using the default tile size.
                    Tiled TIFF organizes the image as an array of smaller images (tiles) in order
                    to enable random access.

               tiff:tile-geometry=<width>x<height>

                    Specify  the  tile  size  to  use  while writing tiled TIFF. Width and height
                    should be a multiple of 16. If the value is not a multiple  of  16,  then  it
                    will  be rounded down. Enables tiled TIFF if it has not already been enabled.
                    GraphicsMagick does not use tiled storage internally  so  tiles  need  to  be
                    converted back and forth from the internal scanline-oriented storage to tile-
                    oriented storage. Testing with typical RGB images shows  that  useful  square
                    tile  size values range from 128x128 to 1024x1024. Large images which require
                    using a disk-based pixel cache benefit from large  tile  sizes  while  images
                    which fit in memory work well with smaller tile sizes.

               tiff:tile-width=<width>

                    Specify  the  tile  width to use while writing tiled TIFF. The tile height is
                    then defaulted to an appropriate size. Width should be a multiple of  16.  If
                    the  value  is  not  a multiple of 16, then it will be rounded down.  Enables
                    tiled TIFF if it has not already been enabled.

               tiff:tile-height=<height>

                    Specify the tile height to use while writing tiled TIFF. The  tile  width  is
                    then  defaulted to an appropriate size. Height should be a multiple of 16. If
                    the value is not a multiple of 16, then it will  be  rounded  down.   Enables
                    tiled TIFF if it has not already been enabled.

               tiff:webp-lossless={TRUE|FALSE}

                    Specify a value of TRUE to enable lossless mode while writing WebP-compressed
                    TIFF files. The WebP webp:lossless option may  also  be  used.   The  quality
                    factor  set  by  the  -quality  option  may be used to influence the level of
                    effort expended while compressing.

               tiff:zstd-compress-level=<value>

                    Specify the compression level  to  use  while  writing  Zstd-compressed  TIFF
                    files.  The valid range is 1 to 22. If this define is not specified, then the
                    'quality' value is used such that  the  default  quality  setting  of  75  is
                    translated to a compress level of 9 such that ´quality' has a useful range of
                    10-184 if used for this purpose.

               webp:lossless={true|false}

                    Enable lossless encoding.

               webp:method={0-6}

                    Quality/speed trade-off.

               webp:image-hint={default,graph,photo,picture}

                    Hint for image type.

               webp:target-size=<integer>

                    Target size in bytes.

               webp:target-psnr=<float>

                    Minimal distortion to try to achieve.

               webp:segments={1-4}

                    Maximum number of segments to use.

               webp:sns-strength={0-100}

                    Spatial Noise Shaping.

               webp:filter-strength={0-100}

                    Filter strength.

               webp:filter-sharpness={0-7}

                    Filter sharpness.

               webp:filter-type={0,1}

                    Filtering type. 0 = simple, 1 = strong (only used if filter-strength >  0  or
                    autofilter is enabled).

               webp:auto-filter={true|false}

                    Auto adjust filter's strength.

               webp:alpha-compression=<integer>

                    Algorithm  for  encoding  the alpha plane (0 = none, 1 = compressed with WebP
                    lossless). Default is 1.

               webp:alpha-filtering=<integer>

                    Predictive filtering method for alpha plane.  0:  none,  1:  fast,  2:  best.
                    Default is 1.

               webp:alpha-quality={0-100}

                    Between 0 (smallest size) and 100 (lossless). Default is 100.

               webp:pass=[1..10]

                    Number of entropy-analysis passes.

               webp:show-compressed={true|false}

                    Export the compressed picture back.  In-loop filtering is not applied.

               webp:preprocessing=[0,1,2]

                    0=none, 1=segment-smooth, 2=pseudo-random dithering

               webp:partitions=[0-3]

                    log2(number  of  token  partitions)  in  [0..3].   Default  is  0  for easier
                    progressive decoding.

               webp:partition-limit={0-100}

                    Quality degradation allowed to fit the 512k limit on prediction modes  coding
                    (0: no degradation, 100: maximum possible degradation).

               webp:emulate-jpeg-size={true|false}

                    If true, compression parameters will be remapped to better match the expected
                    output size from JPEG compression. Generally, the output size will be similar
                    but the degradation will be lower.

               webp:thread-level=<integer>

                    If non-zero, try and use multi-threaded encoding.

               webp:low-memory={true|false}

                    If set, reduce memory usage (but increase CPU use)

               webp:use-sharp-yuv={true|false}

                    If set, if needed, use sharp (and slow) RGB->YUV conversion

               For example, to create a postscript file that will render only the black pixels of
               a bilevel image, use:

                   gm convert bilevel.tif -define ps:imagemask eps3:stencil.ps

       -delay <1/100ths of a second>
              display the next image after pausing

              This option is useful for regulating the animation  of  image  sequences  Delay/100
              seconds  must  expire before the display of the next image. The default is no delay
              between each showing of the image sequence. The maximum delay is 65535.

              You can specify a delay range (e.g. -delay  10-500)  which  sets  the  minimum  and
              maximum delay.

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image This option specifies the
              image resolution to store while encoding a raster image or  the  canvas  resolution
              while rendering (reading) vector formats such as Postscript, PDF, WMF, and SVG into
              a raster image. Image resolution  provides  the  unit  of  measure  to  apply  when
              rendering  to  an  output device or raster image. The default unit of measure is in
              dots per inch (DPI). The -units option may be used to select  dots  per  centimeter
              instead.
               The  default  resolution is 72 dots per inch, which is equivalent to one point per
              pixel (Macintosh and Postscript standard). Computer screens are normally 72  or  96
              dots  per  inch  while  printers  typically support 150, 300, 600, or 1200 dots per
              inch. To determine the resolution of your display, use a ruler to measure the width
              of  your screen in inches, and divide by the number of horizontal pixels (1024 on a
              1024x768 display).  If the file format supports it, this  option  may  be  used  to
              update  the  stored  image resolution. Note that Photoshop stores and obtains image
              resolution from a proprietary embedded profile. If this  profile  is  not  stripped
              from  the  image,  then Photoshop will continue to treat the image using its former
              resolution, ignoring the image resolution specified in the  standard  file  header.
              The  density option is an attribute and does not alter the underlying raster image.
              It may be used to adjust the rendered  size  for  desktop  publishing  purposes  by
              adjusting  the  scale  applied to the pixels. To resize the image so that it is the
              same size at a different resolution, use the -resample option.

       -depth <value>
              depth of the image

              This is the number of bits of color to preserve in the image. Any value  between  1
              and  QuantumDepth  (build  option)  may be specified, although 8 or 16 are the most
              common values. Use this option to specify the depth of raw images  whose  depth  is
              unknown  such  as  GRAY, RGB, or CMYK, or to change the depth of any image after it
              has been read.  The depth option is applied to the pixels immediately so it may  be
              used  as  a  form  of  simple compression by discarding the least significant bits.
              Reducing the depth in advance may speed up  color  quantization,  and  help  create
              smaller file sizes when using a compression algorithm like LZW or ZIP.

       -descend
              obtain image by descending window hierarchy

       -despeckle
              reduce the speckles within an image

       -displace <horizontal scale>x<vertical scale>
              shift image pixels as defined by a displacement map

              With this option, composite image is used as a displacement map.  Black, within the
              displacement map, is a maximum positive displacement.  White is a maximum  negative
              displacement  and  middle gray is neutral.  The displacement is scaled to determine
              the pixel shift.  By default, the displacement applies in both the  horizontal  and
              vertical  directions.   However,  if  you  specify  mask,  composite  image  is the
              horizontal X displacement and mask the vertical Y displacement.

       -display <host:display[.screen]>
              specifies the X server to contact

              This option is used with convert for obtaining image or font from  this  X  server.
              See X(1).

       -dispose <method>
              GIF disposal method

              The  Disposal  Method indicates the way in which the graphic is to be treated after
              being displayed.

              Here are the valid methods:

                  Undefined       No disposal specified.
                  None            Do not dispose between frames.
                  Background      Overwrite the image area with
                                  the background color.
                  Previous        Overwrite the image area with
                                  what was there prior to rendering
                                  the image.

       -dissolve <percent>
              dissolve an image into another by the given percent

              The opacity of the composite image is multiplied by the given percent, then  it  is
              composited over the main image.

       -dither
              apply Floyd/Steinberg error diffusion to the image

              The  basic  strategy  of  dithering  is  to  trade intensity resolution for spatial
              resolution by averaging the intensities  of  several  neighboring  pixels.   Images
              which  suffer from severe contouring when reducing colors can be improved with this
              option.

              The -colors or -monochrome option is required for this option to take effect.

              Use +dither to turn off dithering and to render PostScript without text or  graphic
              aliasing.  Disabling dithering often (but not always) leads to decreased processing
              time.

       -draw <string>
              annotate an image with one or more graphic primitives

              Use this option to annotate an image with one  or  more  graphic  primitives.   The
              primitives  include shapes, text, transformations, and pixel operations.  The shape
              primitives are

                   point           x,y
                   line            x0,y0 x1,y1
                   rectangle       x0,y0 x1,y1
                   roundRectangle  x0,y0 x1,y1 wc,hc
                   arc             x0,y0 x1,y1 a0,a1
                   ellipse         x0,y0 rx,ry a0,a1
                   circle          x0,y0 x1,y1
                   polyline        x0,y0  ...  xn,yn
                   polygon         x0,y0  ...  xn,yn
                   Bezier          x0,y0  ...  xn,yn
                   path            path specification
                   image           operator x0,y0 w,h filename

              The text primitive is

                   text            x0,y0 string

              The text gravity primitive is

                   gravity         NorthWest, North, NorthEast, West, Center,
                                   East, SouthWest, South, or SouthEast

              The text gravity primitive only affects the placement of text and does not interact
              with  the  other  primitives.   It  is equivalent to using the -gravity commandline
              option, except that it is limited in scope to the -draw option in which it appears.

              The transformation primitives are

                   rotate          degrees
                   translate       dx,dy
                   scale           sx,sy
                   skewX           degrees
                   skewY           degrees

              The pixel operation primitives are

                   color           x0,y0 method
                   matte           x0,y0 method

              The shape primitives are drawn in the color  specified  in  the  preceding  -stroke
              option.  Except  for  the line and point primitives, they are filled with the color
              specified in the preceding -fill option.  For unfilled shapes, use -fill none.

              Point requires a single coordinate.

              Line requires a start and end coordinate.

              Rectangle expects an upper left and lower right coordinate.

              RoundRectangle has the upper left and lower right coordinates  and  the  width  and
              height of the corners.

              Circle has a center coordinate and a coordinate for the outer edge.

              Use Arc to inscribe an elliptical arc within a rectangle.  Arcs require a start and
              end point as well as the degree of rotation (e.g. 130,30 200,100 45,90).

              Use Ellipse to draw a partial ellipse centered at the given point with  the  x-axis
              and y-axis radius and start and end of arc in degrees (e.g. 100,100 100,150 0,360).

              Finally,  polyline  and  polygon  require  three  or more coordinates to define its
              boundaries.  Coordinates are integers separated by an optional comma.  For example,
              to define a circle centered at 100,100 that extends to 150,150 use:

                   -draw 'circle 100,100 150,150'

              Paths  (See  Paths)  represent an outline of an object which is defined in terms of
              moveto (set a new current point), lineto (draw a straight line),  curveto  (draw  a
              curve  using a cubic Bezier), arc (elliptical or circular arc) and closepath (close
              the current shape by drawing a line to the last moveto)  elements.  Compound  paths
              (i.e.,  a path with subpaths, each consisting of a single moveto followed by one or
              more line or curve operations) are possible to allow effects such as "donut  holes"
              in objects.

              Use  image  to composite an image with another image. Follow the image keyword with
              the composite operator, image location, image size, and filename:

                   -draw 'image Over 100,100 225,225 image.jpg'

              You can use 0,0 for the image size, which means to use the actual dimensions  found
              in  the  image  header.  Otherwise, it will be scaled to the given dimensions.  See
              -compose for a description of the composite operators.

              Use text to annotate an image with text. Follow the text coordinates with a string.
              If  the  string  has  embedded  spaces,  enclose  it  in  single  or double quotes.
              Optionally you can include the image filename, type, width, height, or other  image
              attribute by embedding special format character. See -comment for details.

              For example,

                   -draw 'text 100,100 "%m:%f %wx%h"'

              annotates the image with MIFF:bird.miff 512x480 for an image titled
              bird.miff
              and whose width is 512 and height is 480.

              If the first character of string is @, the text is read
              from a file titled by the remaining characters in the string.  Please
              note that if the string comes from an untrusted source that it should
              be sanitized before use (a security risk).

              Rotate rotates subsequent shape primitives and text primitives about
              the origin of the main image. If the -region option precedes the
              -draw option, the origin for transformations is the upper left
              corner of the region.

              Translate translates them.

              Scale scales them.

              SkewX and SkewY skew them with respect to the origin of
              the main image or the region.

              The transformations modify the current affine matrix, which is initialized
              from the initial affine matrix defined by the -affine option.
              Transformations are cumulative within the -draw option.
              The initial affine matrix is not affected; that matrix is only changed by the
              appearance of another -affine option.  If another -draw
              option appears, the current affine matrix is reinitialized from
              the initial affine matrix.

              Use color to change the color of a pixel to the fill color (see
              -fill). Follow the pixel coordinate
              with a method:

                   point
                   replace
                   floodfill
                   filltoborder
                   reset

              Consider  the  target  pixel as that specified by your coordinate. The point method
              recolors the target pixel. The replace method recolors any pixel that  matches  the
              color  of the target pixel.  Floodfill recolors any pixel that matches the color of
              the target pixel and is a neighbor,  whereas  filltoborder  recolors  any  neighbor
              pixel that is not the border color. Finally, reset recolors all pixels.

              Use  matte  to  the  change  the pixel matte value to transparent. Follow the pixel
              coordinate with a method (see the color primitive for a  description  of  methods).
              The  point  method  changes the matte value of the target pixel. The replace method
              changes the matte value of any pixel that matches the color of  the  target  pixel.
              Floodfill changes the matte value of any pixel that matches the color of the target
              pixel and is a neighbor, whereas  filltoborder  changes  the  matte  value  of  any
              neighbor  pixel that is not the border color (-bordercolor).  Finally reset changes
              the matte value of all pixels.

              You can set the primitive color, font, and font  bounding  box  color  with  -fill,
              -font,  and  -box  respectively.  Options are processed in command line order so be
              sure to use these options before the -draw option.

       -edge <radius>
              detect edges within an image

       -emboss <radius>
              emboss an image

       -encoding <type>
              specify the text encoding

              Choose from AdobeCustom,  AdobeExpert,  AdobeStandard,  AppleRoman,  BIG5,  GB2312,
              Latin 2, None, SJIScode, Symbol, Unicode, Wansung.

       -endian <type>
              specify endianness (MSB, LSB, or Native) of image

              MSB  indicates  big-endian  (e.g.  SPARC, Motorola 68K) while LSB indicates little-
              endian (e.g. Intel 'x86, VAX) byte ordering.  Native indicates to  use  the  normal
              ordering for the current CPU.  This option currently only influences the CMYK, DPX,
              GRAY, RGB, and TIFF, formats.

              Use +endian to revert to unspecified endianness.

       -enhance
              apply a digital filter to enhance a noisy image

       -equalize
              perform histogram equalization to the image

       -extent <width>x<height>{+-}<x>{+-}<y>
              composite image on background color canvas image

              This option composites the image on a new  background  color  (-background)  canvas
              image  of  size  <width>x<height>.  The existing image content is composited at the
              position specified by geometry x and y offset  and/or  desired  gravity  (-gravity)
              using  the  current  image  compose  (-compose)  method.  Image content which falls
              outside the bounds of the new image dimensions is discarded.

              For example, this command creates a thumbnail of an image, and centers it on a  red
              color  backdrop image, offsetting the canvas ten pixels to the left and five pixels
              up, with respect to the thumbnail:

                  gm convert infile.jpg -thumbnail 120x80 -background red -gravity center \
                            -extent 140x100-10-5 outfile.jpg

              This command reduces or expands a JPEG image to fit on an 800x600 display:

                  gm convert -size 800x600 input.jpg \
                            -resize 800x600 -background black \
                            -compose Copy -gravity center \
                            -extent 800x600 \
                            -quality 92 output.jpg

              If the aspect ratio of the input  image  isn't  exactly  4:3,  then  the  image  is
              centered on an 800x600 black canvas.

       -file <filename>
              write annotated difference image to file

              If  -file is specified, then an annotated difference image is generated and written
              to the specified file. Pixels which differ between the reference and compare images
              are modified from those in the compare image so that the changed pixels become more
              obvious.  Some images may require  use  of  an  alternative  highlight  style  (see
              -highlight-style)  or highlight color (see -highlight-color) before the changes are
              obvious.

       -fill <color>
              color to use when filling a graphic primitive

              Colors are represented in GraphicsMagick in the same form  used  by  SVG.  Use  "gm
              convert -list color" to list named colors:

                  name               (named color)
                  #RGB               (hex numbers, 4 bits each)
                  #RRGGBB            (8 bits each)
                  #RRRGGGBBB         (12 bits each)
                  #RRRRGGGGBBBB      (16 bits each)
                  #RGBA              (4 bits each)
                  #RRGGBBAA          (8 bits each)
                  #RRRGGGBBBAAA      (12 bits each)
                  #RRRRGGGGBBBBAAAA  (16 bits each)
                  rgb(r,g,b)         (r,g,b are decimal numbers)
                  rgba(r,g,b,a)      (r,g,b,a are decimal numbers)

              Enclose  the  color  specification  in  quotation  marks  to prevent the "#" or the
              parentheses from being interpreted by your shell.

              For example,

                  gm convert -fill blue ...
                  gm convert -fill "#ddddff" ...
                  gm convert -fill "rgb(65000,65000,65535)" ...

              The shorter forms are scaled up, if necessary by replication.  For  example,  #3af,
              #33aaff, and #3333aaaaffff are all equivalent.

              See -draw for further details.

       -filter <type>
              use this type of filter when resizing an image

              Use  this  option  to  affect  the  resizing operation of an image (see -geometry).
              Choose from these filters (ordered by approximate increasing CPU time):

                   Point
                   Box
                   Triangle
                   Hermite
                   Hanning
                   Hamming
                   Blackman
                   Gaussian
                   Quadratic
                   Cubic
                   Catrom
                   Mitchell
                   Lanczos
                   Bessel
                   Sinc

              The default filter is automatically selected to  provide  the  best  quality  while
              consuming  a  reasonable  amount  of time. The Mitchell filter is used if the image
              supports a palette, supports a matte channel, or is being enlarged,  otherwise  the
              Lanczos filter is used.

       -flatten
              flatten a sequence of images

              In  some  file  formats (e.g. Photoshop's PSD) complex images may be represented by
              "layers" (independent images) which must be composited in order to obtain the final
              rendition.   The  -flatten  option  accomplishes this composition.  The sequence of
              images is replaced by a single image created by compositing  each  image  in  turn,
              while  respecting  composition  operators  and  page  offsets.   While  -flatten is
              immediately useful for eliminating layers, it is also useful as  a  general-purpose
              composition tool.

              The  sequence  of  images  is  terminated  by the appearance of any option.  If the
              -flatten option appears after all of the input images, all  images  are  flattened.
              Also  see -mosaic which is similar to -flatten except that it adds a suitably-sized
              canvas base image.

              For example, this composites an image on top of a 640x400 transparent black  canvas
              image:

                  gm convert -size 640x300 xc:transparent \
                            -compose over -page +0-100 \
                            frame.png -flatten output.png

              and this flattens a Photoshop PSD file:

                  gm convert input.psd -flatten output.png

       -flip  create a "mirror image"

              reflect the scanlines in the vertical direction.

       -flop  create a "mirror image"

              reflect the scanlines in the horizontal direction.

       -font <name>
              use this font when annotating the image with text

              You  can  tag  a font to specify whether it is a PostScript, TrueType, or X11 font.
              For example, Arial.ttf is a TrueType font, ps:helvetica is PostScript, and  x:fixed
              is X11.

       -foreground <color>
              define the foreground color

              The color is specified using the format described under the -fill option.

       -format <type>
              the image format type

              When used with the mogrify utility, this option will convert any image to the image
              format you specify.  See  GraphicsMagick(1)  for  a  list  of  image  format  types
              supported by GraphicsMagick, or see the output of 'gm -list format'.

              By  default  the  file  is  written to its original name.  However, if the filename
              extension matches a supported format, the extension  is  replaced  with  the  image
              format type specified with -format.  For example, if you specify tiff as the format
              type and the input image filename is image.gif, the output image  filename  becomes
              image.tiff.

       -format <string>
              output formatted image characteristics

              When  used with the identify utility, or the convert utility with output written to
              the 'info:-' file specification, use this option to  print  information  about  the
              image  in  a  format  of  your choosing.  You can include the image filename, type,
              width, height, Exif data, or other image attributes  by  embedding  special  format
              characters:

                   %b   file size
                   %c   comment
                   %d   directory
                   %e   filename extension
                   %f   filename
                   %g   page dimensions and offsets
                   %h   height
                   %i   input filename
                   %k   number of unique colors
                   %l   label
                   %m   magick
                   %n   number of scenes
                   %o   output filename
                   %p   page number
                   %q   image bit depth
                   %r   image type description
                   %s   scene number
                   %t   top of filename
                   %u   unique temporary filename
                   %w   width
                   %x   horizontal resolution
                   %y   vertical resolution
                   %A   transparency supported
                   %C   compression type
                   %D   GIF disposal method
                   %G   Original width and height
                   %H   page height
                   %M   original filename specification
                   %O   page offset (x,y)
                   %P   page dimensions (width,height)
                   %Q   compression quality
                   %T   time delay (in centi-seconds)
                   %U   resolution units
                   %W   page width
                   %X   page horizontal offset (x)
                   %Y   page vertical offset (y)
                   %@   trim bounding box
                   %#   signature
                   \n   newline
                   \r   carriage return
                   %%   %

              For example,

                   -format "%m:%f %wx%h"

              displays  MIFF:bird.miff  512x480  for an image titled bird.miff and whose width is
              512 and height is 480.

              If the first character of string is @, the format is read from a file titled by the
              remaining  characters  in the string.  Please note that if the string comes from an
              untrusted source that it should be sanitized before use since this may be  used  to
              incorporate any readable file on the system (a security risk).

              The values of image type (%r) which may be returned include:

                   Bilevel
                   Grayscale
                   GrayscaleMatte
                   Palette
                   PaletteMatte
                   TrueColor
                   TrueColorMatte
                   ColorSeparation
                   ColorSeparationMatte
                   Optimize

              You  can also use the following special formatting syntax to print Exif information
              contained in the file:

                   %[EXIF:<tag>]

              Where "<tag>" may be one of the following:

                   *  (print all Exif tags, in keyword=data format)
                   !  (print all Exif tags, in tag_number format)
                   #hhhh (print data for Exif tag #hhhh)
                   ImageWidth
                   ImageLength
                   BitsPerSample
                   Compression
                   PhotometricInterpretation
                   FillOrder
                   DocumentName
                   ImageDescription
                   Make
                   Model
                   StripOffsets
                   Orientation
                   SamplesPerPixel
                   RowsPerStrip
                   StripByteCounts
                   XResolution
                   YResolution
                   PlanarConfiguration
                   ResolutionUnit
                   TransferFunction
                   Software
                   DateTime
                   Artist
                   WhitePoint
                   PrimaryChromaticities
                   TransferRange
                   JPEGProc
                   JPEGInterchangeFormat
                   JPEGInterchangeFormatLength
                   YCbCrCoefficients
                   YCbCrSubSampling
                   YCbCrPositioning
                   ReferenceBlackWhite
                   CFARepeatPatternDim
                   CFAPattern
                   BatteryLevel
                   Copyright
                   ExposureTime
                   FNumber
                   IPTC/NAA
                   ExifOffset
                   InterColorProfile
                   ExposureProgram
                   SpectralSensitivity
                   GPSInfo
                   ISOSpeedRatings
                   OECF
                   ExifVersion
                   DateTimeOriginal
                   DateTimeDigitized
                   ComponentsConfiguration
                   CompressedBitsPerPixel
                   ShutterSpeedValue
                   ApertureValue
                   BrightnessValue
                   ExposureBiasValue
                   MaxApertureValue
                   SubjectDistance
                   MeteringMode
                   LightSource
                   Flash
                   FocalLength
                   MakerNote
                   UserComment
                   SubSecTime
                   SubSecTimeOriginal
                   SubSecTimeDigitized
                   FlashPixVersion
                   ColorSpace
                   ExifImageWidth
                   ExifImageLength
                   InteroperabilityOffset
                   FlashEnergy
                   SpatialFrequencyResponse
                   FocalPlaneXResolution
                   FocalPlaneYResolution
                   FocalPlaneResolutionUnit
                   SubjectLocation
                   ExposureIndex
                   SensingMethod
                   FileSource
                   SceneType

              JPEG specific information (from reading a JPEG file) may be obtained like this:

                   %[JPEG-<tag>]

              Where "<tag>" may be one of the following:

                   *                 (all JPEG-related tags, in
                                      keyword=data format)
                   Quality           IJG JPEG "quality" estimate
                   Colorspace        JPEG colorspace numeric ID
                   Colorspace-Name   JPEG colorspace name
                   Sampling-factors  JPEG sampling factors

              Please note that JPEG has no notion of "quality" and that the quality  metric  used
              by, and estimated by the software is based on the quality metric established by IJG
              JPEG 6b.  Other encoders (e.g. that used by Adobe Photoshop) use different encoding
              metrics.

              Surround  the  format specification with quotation marks to prevent your shell from
              misinterpreting any spaces and square brackets.

       -frame <width>x<height>+<outer bevel width>+<inner bevel width>
              surround the image with an ornamental border

              See -geometry for details about the geometry specification.  The -frame  option  is
              not affected by the -gravity option.

              The color of the border is specified with the -mattecolor command line option.

       -frame include the X window frame in the imported image

       -fuzz <distance>{%}
              colors within this Euclidean distance are considered equal

              A  number  of  algorithms  search  for a target color. By default the color must be
              exact. Use this option to match colors that are close (in  Euclidean  distance)  to
              the  target  color  in RGB 3D space. For example, if you want to automatically trim
              the edges of an image  with  -trim  but  the  image  was  scanned  and  the  target
              background  color  may  differ by a small amount. This option can account for these
              differences.

              The distance can be in  absolute  intensity  units  or,  by  appending  "%",  as  a
              percentage of the maximum possible intensity (255, 65535, or 4294967295).

       -gamma <value>
              level of gamma correction

              The same color image displayed on two different workstations may look different due
              to differences in the display monitor. Use gamma  correction  to  adjust  for  this
              color  difference.  Reasonable  values  extend from 0.8 to 2.3. Gamma less than 1.0
              darkens the image and gamma greater than 1.0  lightens  it.  Large  adjustments  to
              image  gamma  may result in the loss of some image information if the pixel quantum
              size is only eight bits (quantum range 0 to 255).

              You can apply separate gamma values to the red, green, and  blue  channels  of  the
              image with a gamma value list delimited with slashes (e.g., 1.7/2.3/1.2).

              Use  +gamma value to set the image gamma level without actually adjusting the image
              pixels. This option is useful if the image is of a known gamma but not  set  as  an
              image attribute (e.g. PNG images).

       -gaussian <radius>{x<sigma>}
              blur the image with a Gaussian operator

              Use the given radius and standard deviation (sigma).

       -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
              Specify dimension, offset, and resize options.

              The  -geometry  option is used for a number of different purposes, depending on the
              utility it is used with.

              For the X11  commands  ('animate',  'display',  and  'import'),  it  specifies  the
              preferred  size  and  location of the Image window.  By default, the window size is
              the image size and the location is chosen by you (or your window manager)  when  it
              is mapped.
               For  the 'import', 'convert', 'mogrify' utility commands it may be used to specify
              the desired size when resizing an image.  In this case, symbols representing resize
              options  may be appended to the geometry string to influence how the resize request
              is treated.

              See later notes corresponding to usage by particular commands.  The following notes
              apply  to  when  -geometry is used to express a resize request, taking into account
              the current properties of the image.

              By default, the width and height are maximum values. That is, the image is expanded
              or  contracted to fit the width and height value while maintaining the aspect ratio
              of the image.

              Append a ^ to the geometry so that the image aspect ratio is  maintained  when  the
              image  is  resized, but the resulting width or height are treated as minimum values
              rather than maximum values.

              Append a ! (exclamation point) to the geometry to force the image size  to  exactly
              the  size  you specify. For example, if you specify 640x480! the image width is set
              to 640 pixels and height to 480.

              If only the width is specified, without the trailing 'x', then  height  is  set  to
              width (e.g., -geometry 100 is the same as -geometry 100x100).  If only the width is
              specified but with the trailing 'x', then width assumes the value and the height is
              chosen to maintain the aspect ratio of the image.  Similarly, if only the height is
              specified prefixed by 'x' (e.g., -geometry x256), the width is chosen  to  maintain
              the aspect ratio.

              To  specify  a  percentage  width  or  height  instead, append %. The image size is
              multiplied  by  the  width  and  height  percentages  to  obtain  the  final  image
              dimensions.  To  increase  the size of an image, use a value greater than 100 (e.g.
              125%). To decrease an image's size, use a percentage less than 100.

              Use @ to specify the maximum area in pixels of an image.

              Use > to change the dimensions of the image only if its width or height exceeds the
              geometry specification. < resizes the image only if both of its dimensions are less
              than the geometry specification. For example, if you  specify  '640x480>'  and  the
              image  size  is  256x256,  the image size does not change. However, if the image is
              512x512 or 1024x1024, it is resized to 480x480.  Enclose the geometry specification
              in  quotation marks to prevent the < or > from being interpreted by your shell as a
              file redirection.

              When used with animate and display, offsets are handled in the same  manner  as  in
              X(1)  and  the  -gravity  option  is not used.  If the x is negative, the offset is
              measured leftward from the right edge of the screen to the right edge of the  image
              being  displayed.  Similarly, negative y is measured between the bottom edges.  The
              offsets are not affected by "%"; they are always measured in pixels.

              When used as a composite option, -geometry gives the dimensions of  the  image  and
              its  location  with  respect  to  the  composite  image.  If the -gravity option is
              present with NorthEast, East, or SouthEast gravity, the x represents  the  distance
              from  the  right  edge  of  the  image  to  the  right edge of the composite image.
              Similarly, if the -gravity option is present with SouthWest,  South,  or  SouthEast
              gravity,  y  is  measured  between the bottom edges. Accordingly, a positive offset
              will never point in the direction outside  of  the  image.   The  offsets  are  not
              affected  by "%"; they are always measured in pixels.  To specify the dimensions of
              the composite image, use the -resize option.

              When used as a convert, import or mogrify  option,  -geometry  is  synonymous  with
              -resize  and  specifies the size of the output image.  The offsets, if present, are
              ignored.

              When used as a montage option, -geometry specifies the image size and  border  size
              for  each  tile;  default is 256x256+0+0.  Negative offsets (border dimensions) are
              meaningless.  The -gravity option affects the placement of  the  image  within  the
              tile;  the  default gravity for this purpose is Center.  If the "%" sign appears in
              the geometry specification, the tile  size  is  the  specified  percentage  of  the
              original  dimensions  of the first tile.  To specify the dimensions of the montage,
              use the -resize option.

       -gravity <type>
              direction primitive  gravitates to when annotating the image.

              Choices are: NorthWest, North, NorthEast, West,  Center,  East,  SouthWest,  South,
              SouthEast.

              The  direction  you choose specifies where to position the text when annotating the
              image. For example Center gravity forces the text to be centered within the  image.
              By  default,  the  image  gravity  is  NorthWest.  See -draw for more details about
              graphic primitives.  Only the text primitive is affected by the -gravity option.

              The -gravity option is also used in concert with the  -geometry  option  and  other
              options  that  take  <geometry>  as  a  parameter,  such  as the -crop option.  See
              -geometry for details of how the -gravity option interacts with  the  <x>  and  <y>
              parameters of a geometry specification.

              When  used  as  an option to composite, -gravity gives the direction that the image
              gravitates within the composite.

              When used as an option to montage, -gravity  gives  the  direction  that  an  image
              gravitates within a tile.  The default gravity is Center for this purpose.

       -green-primary <x>,<y>
              green chromaticity primary point

       -hald-clut <clut>
              apply a Hald CLUT to the image

              A  Hald CLUT ("Color Look-Up Table") is a special square color image which contains
              a look-up table for red, green, and blue.  The size  of  the  Hald  CLUT  image  is
              determined  by its order.  The width (and height) of a Hald CLUT is the cube of the
              order.  For example, a Hald CLUT of order 8 is 512x512 pixels (262,144 colors)  and
              of  order 16 is 4096x4096 (16,777,216 colors).  A special CLUT is the identity CLUT
              which which causes no change to the input image.  In order to use  the  Hald  CLUT,
              one  takes  an identity CLUT and adjusts its colors in some way.  The modified CLUT
              can then be used to transform any number of images in an identical way.

              GraphicsMagick contains a built-in identity CLUT generator via the IDENTITY  coder.
              For example reading from the file name IDENTITY:8 returns an identity CLUT of order
              8.  Typical Hald CLUT identity images have an order  of  between  8  and  16.   The
              default order for the IDENTITY CLUT generator is 8.  Interpolation is used so it is
              not usually necessary for CLUT images to be very large.  The  PNG  file  format  is
              ideal for storing Hald CLUT images because it compresses them very well.

       -help  print usage instructions

       -highlight-color <color>
              pixel annotation color

              Specifies the color to use when annotating difference pixels.

       -highlight-style <style>
              pixel annotation style

              Specifies  the  pixel difference annotation style used to draw attention to changed
              pixels. May be one of Assign, Threshold, Tint, or XOR; where  Assign  replaces  the
              pixel with the highlight color (see -highlight-color), Threshold replaces the pixel
              with black or white based on the difference in  intensity,  Tint  alpha  tints  the
              pixel  with  the  highlight  color,  and  XOR does an XOR between the pixel and the
              highlight color.

       -iconGeometry <geometry>
              specify the icon geometry

              Offsets, if present in the geometry specification, are handled in the  same  manner
              as the -geometry option, using X11 style to handle negative offsets.

       -iconic
              iconic animation

       -immutable
              make image immutable

       -implode <factor>
              implode image pixels about the center

       -intent <type>
              use this type of rendering intent when managing the image color

              Use  this  option  to  affect  the  the color management operation of an image (see
              -profile).  Choose from these intents: Absolute, Perceptual, Relative, Saturation.

              The default intent is undefined.

       -interlace <type>
              the type of interlacing scheme

              Choices are: None, Line, Plane, or Partition. The default is None.

              This option is used to specify the type of interlacing scheme for raw image formats
              such as RGB or YUV.  None means do not interlace (RGBRGBRGBRGBRGBRGB...),

              Line  uses  scanline  interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and Plane
              uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).

              Partition is like plane except the different planes are saved to  individual  files
              (e.g. image.R, image.G, and image.B).

              Use Line to create an interlaced PNG or  GIF or progressive JPEG image.

       -label <name>
              assign a label to an image

              Use  this  option to assign a specific label to the image, when writing to an image
              format that supports labels, such as  TIFF,  PNG,  MIFF,  or  PostScript.  You  can
              include  the  the  image filename, type, width, height, or other image attribute by
              embedding special format character.  A label is not drawn  on  the  image,  but  is
              embedded  in  the  image datastream via a "Label" tag or similar mechanism.  If you
              want the label to be visible on the  image  itself,  use  the  -draw  option.   See
              -comment for details.

              For example,

                   -label "%m:%f %wx%h"

              produces an image label of MIFF:bird.miff 512x480 for an image titled bird.miff and
              whose width is 512 and height is 480.

              If the first character of string is @, the image label is read from a  file  titled
              by  the  remaining  characters in the string.  Please note that if the string comes
              from an untrusted source that it should be sanitized before use since otherwise the
              content of an arbitrary readable file might be incorporated into the image label (a
              security risk).

              If the -label option appears multiple times, only the last label is stored.

              In PNG images, the label is stored in  a  tEXt  or  zTXt  chunk  with  the  keyword
              "label".

              When  converting to PostScript, use this option to specify a header string to print
              above the image. Specify the label font with -font.

              When creating a montage, by default the label associated with an image is displayed
              with the corresponding tile in the montage.  Use the +label option to suppress this
              behavior.

       -lat <width>x<height>{+-}<offset>{%}
              perform local adaptive thresholding

              Perform local adaptive thresholding using the specified width, height, and  offset.
              The  offset  is  a  distance  in sample space from the mean, as an absolute integer
              ranging from 0 to the maximum sample value or as  a  percentage.   If  the  percent
              option  is  supplied,  then  the  offset is computed as a percentage of the quantum
              range.  It is strongly recommended to use the percent option so  that  results  are
              not sensitive to pixel quantum depth.

              For example,

                   -colorspace gray -lat "10x10-5%"

              will  help  clarify  a  scanned  grayscale  or color document, producing a bi-level
              equivalent.

       -level <black_point>{,<gamma>}{,<white_point>}{%}
              adjust the level of image contrast

              Give one, two or three values delimited with  commas:  black-point,  gamma,  white-
              point  (e.g.  10,1.0,250 or 2%,0.5,98%). The black and white points range from 0 to
              MaxRGB or from 0 to 100%; if the white point  is  omitted  it  is  set  to  MaxRGB-
              black_point.  If  a "%" sign is present anywhere in the string, the black and white
              points are percentages of MaxRGB. Gamma is an exponent that ranges from 0.1 to 10.;
              if  it  is  omitted,  the  default  of  1.0  (no gamma correction) is assumed. This
              interface works  similar  to  Photoshop's  "Image->Adjustments->Levels..."   "Input
              Levels" interface.

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

              By  default,  resource  limits  are  estimated based on the available resources and
              capabilities of the system. The resource limits are Disk, maximum total disk  space
              consumed; File, maximum number of file descriptors allowed to be open at once; Map,
              maximum total number of file bytes which may  be  memory  mapped;  Memory,  maximum
              total  number  of  bytes  of  heap  memory  used for image storage; Pixels, maximum
              absolute image size (per image); Width, maximum image pixels width; Height, maximum
              image  pixels  height;  Read,  maximum  number  of  uncompressed bytes to read; and
              Threads, the maximum number of worker threads to use per OpenMP thread team.

              The Disk and Map resource limits are used to decide if  (for  a  given  image)  the
              decoded  image  ("pixel cache") should be stored in heap memory (RAM), in a memory-
              mapped disk file, or in a disk file accessed via read/write I/O.

              The number  of  total  pixels  in  one  image  (Pixels),  and/or  the  width/height
              (Width/Height), may be limited in order to force the reading, or creation of images
              larger than the limit (in pixels) to intentionally  fail.  The  disk  limit  (Disk)
              establishes an overall limit since using the disk is the means of last resort. When
              the disk limit has been reached, no more images may be read.

              The amount of uncompressed data read when reading one image may be limited  by  the
              Read  limit.  Reading the image fails when the limit is hit.  This option is useful
              if the data is read from a stream (pipe) or  from  a  compressed  file  such  as  a
              gzipped  file.  Some files are very compressable and so a small compressed file can
              decompress to a huge amount of data.  This option also defends against files  which
              produce seemingly endless loops while decoding by seeking backwards in the file.

              The  value  argument  is  an  absolute  value,  but may have standard binary suffix
              characters applied ('K', 'M', 'G', 'T', 'P', 'E') to apply a scaling to  the  value
              (based  on  a  multiplier  of  1024).  Any  additional  characters are ignored. For
              example, '-limit Pixels 10MP' limits the maximum image size to  10  megapixels  and
              '-limit  memory  32MB  -limit map 64MB' limits memory and memory mapped files to 32
              megabytes and 64 megabytes respectively.

              Resource limits may also  be  set  using  environment  variables.  The  environment
              variables       MAGICK_LIMIT_DISK,       MAGICK_LIMIT_FILES,      MAGICK_LIMIT_MAP,
              MAGICK_LIMIT_MEMORY, MAGICK_LIMIT_PIXELS, MAGICK_LIMIT_WIDTH,  MAGICK_LIMIT_HEIGHT.
              MAGICK_LIMIT_READ,  and  OMP_NUM_THREADS  may  be  used  to set the limits for disk
              space, open files, memory mapped size, heap memory, per-image pixels, image  width,
              image height, and threads respectively.

              Use the option -list resource list the current limits.

       -linewidth
              the line width for subsequent draw operations

       -list <type>
              the type of list

              Choices  are: Color, Delegate, Format, Magic, Module, Resource, or Type. The Module
              option is only available if GraphicsMagick was built to support loadable modules.

              This option lists information about the GraphicsMagick configuration.

       -log <string>
              Specify format for debug log

              This option specifies the format for the log printed  when  the  -debug  option  is
              active.

              You can display the following components by embedding special format characters:

                   %d   domain
                   %e   event
                   %f   function
                   %l   line
                   %m   module
                   %p   process ID
                   %r   real CPU time
                   %t   wall clock time
                   %u   user CPU time
                   %%   percent sign
                   \n   newline
                   \r   carriage return

              For example:

                  gm convert -debug coders -log "%u %m:%l %e" in.gif out.png

              The default behavior is to print all of the components.

       -loop <iterations>
              add Netscape loop extension to your GIF animation

              A  value  other  than  zero  forces the animation to repeat itself up to iterations
              times.

       -magnify
              magnify the image

              The image size is doubled using linear interpolation.

       -magnify <factor>
              magnify the image

              The displayed image is magnified by factor.

       -map <filename>
              choose a particular set of colors from this image

              [convert or mogrify]

              By default, color reduction chooses an optimal set of colors  that  best  represent
              the  original  image. Alternatively, you can choose a particular set of colors from
              an image file with this option.

              Use +map to reduce all images in the  image  sequence  that  follows  to  a  single
              optimal  set  of colors that best represent all the images.  The sequence of images
              is terminated by the appearance of any option.  If the +map  option  appears  after
              all of the input images, all images are mapped.

       -map <type>
              display image using this type.

              [animate or display]

              Choose from these Standard Colormap types:

                   best
                   default
                   gray
                   red
                   green
                   blue

              The  X  server  must  support  the Standard Colormap you choose, otherwise an error
              occurs. Use list as the type and display searches the list  of  colormap  types  in
              top-to-bottom  order  until one is located. See xstdcmap(1) for one way of creating
              Standard Colormaps.

       -mask <filename>
              Specify a clipping mask

              The image read from the file is used as a clipping mask.  It  must  have  the  same
              dimensions as the image being masked.

              If the mask image contains an opacity channel, the opacity of each pixel is used to
              define the mask.  Otherwise, the intensity (gray level)  of  each  pixel  is  used.
              Unmasked  (black) pixels are modified while masked pixels (not black) are protected
              from alteration.

              Use +mask to remove the clipping mask.

              It is not necessary to use -clip to activate the mask; -clip is implied by -mask.

       -matte store matte channel if the image has one

              If the image does not have a matte channel, create an opaque one.

              Use +matte to ignore the matte channel (treats it as opaque) and to avoid writing a
              matte channel in the output file.

              For  the compare command, -matte will add an opaque matte channel to images if they
              do not already have a matte channel, and matte will be  enabled  for  both  images.
              Likewise,  if  +matte is used, the matte channel is disabled for both images.  This
              makes it easier to compare images regardless  of  if  they  already  have  a  matte
              channel.

       -mattecolor <color>
              specify the color to be used with the -frame option

              The color is specified using the format described under the -fill option.

       -maximum-error <limit>
              specifies the maximum amount of total image error

              Specifies  the  maximum  amount  of  total image error (based on comparison using a
              specified metric) before an error ("image difference exceeds limit")  is  reported.
              The error is reported via a non-zero command execution return status.

       -median <radius>
              apply a median filter to the image

       -metric <metric>
              comparison metric (MAE, MSE, PAE, PSNR, RMSE)

       -minify <factor>
              minify the image

              The image size is halved using linear interpolation.

       -mode <value>
              mode of operation

              The  available  montage  modes  are frame to place the images in a rectangular grid
              while adding a decorative frame  with  dropshadow,  unframe  to  place  undecorated
              images  in  a rectangular grid, and concatenate to pack the images closely together
              without any well-defined grid or decoration.

       -modulate brightness[,saturation[,hue]]
              vary the brightness, saturation, and hue of an image

              Specify the percent change in brightness, color saturation, and  hue  separated  by
              commas.  Default  argument  values  are  100  percent,  resulting in no change. For
              example, to increase the color brightness by 20% and decrease the color  saturation
              by 10% and leave the hue unchanged, use: -modulate 120,90.

              Hue  is  the percentage of absolute rotation from the current position. For example
              50 results in a  counter-clockwise  rotation  of  90  degrees,  150  results  in  a
              clockwise  rotation  of  90 degrees, with 0 and 200 both resulting in a rotation of
              180 degrees.

       -monitor
              show progress indication

              A simple command-line progress indication is shown while the  command  is  running.
              The  process  indication  shows  the  operation  currently  being performed and the
              percent completed. Commands  using  X11  may  replace  the  command  line  progress
              indication with a graphical one once an image has been displayed.

       -monochrome
              transform the image to black and white

       -morph <frames>
              morphs an image sequence

              Both  the image pixels and size are linearly interpolated to give the appearance of
              a meta-morphosis from one image to the next.

              The sequence of images is terminated by the  appearance  of  any  option.   If  the
              -morph option appears after all of the input images, all images are morphed.

       -mosaic
              create a mosaic from an image or an image sequence

              The  -mosaic  option provides a flexible way to composite one or more images onto a
              solid-color canvas image. It works similar to -flatten except that  a  base  canvas
              image  is  automatically  created  with  a suitable size given the image size, page
              dimensions, and page offsets of images to be composited.  The  color  of  the  base
              canvas  image  may  be set via the -background option.  The default canvas color is
              'white', but 'black' or  'transparent'  may  be  more  suitable  depending  on  the
              composition algorithm requested.

              The  -compose  option  may be used to specify the composition algorithm to use when
              compositing the subsequent image on the base canvas.

              The -page option can be used to establish the  dimensions  of  the  mosaic  and  to
              position  the  subsequent  image within the mosaic.  If the -page argument does not
              specify width and height, then the canvas dimensions are  evaluated  based  on  the
              image sizes and offsets.

              The  sequence  of  images  is  terminated  by the appearance of any option.  If the
              -mosaic option appears after all of the input images, all images  are  included  in
              the mosaic.

              The  following  is  an  example of composing an image based on red, green, and blue
              layers extracted from a sequence of images  and  pasted  on  the  canvas  image  at
              specified offsets:

                  gm convert -background black \
                            -compose CopyRed   -page +0-100 red.png \
                            -compose CopyGreen -page +0+40  green.png \
                            -compose CopyBlue  -page +0+180 blue.png \
                            -mosaic output.png

       -motion-blur <radius>{x<sigma>}{+angle}
              Simulate motion blur

              Simulate  motion blur by convolving the image with a Gaussian operator of the given
              radius and standard deviation (sigma). For reasonable  results,  radius  should  be
              larger  than  sigma.  If  radius  is  zero, then a suitable radius is automatically
              selected based on sigma. The angle specifies the angle that the  object  is  coming
              from (side which is blurred).

       -name  name an image

       -negate
              replace every pixel with its complementary color

              The red, green, and blue intensities of an image are negated.  White becomes black,
              yellow becomes blue, etc.  Use +negate to only negate the grayscale pixels  of  the
              image.

       -noise <radius|type>
              add or reduce noise in an image

              The  principal  function  of noise peak elimination filter is to smooth the objects
              within an image without losing edge  information  and  without  creating  undesired
              structures.  The  central idea of the algorithm is to replace a pixel with its next
              neighbor in value within a pixel window, if this pixel has been found to be  noise.
              A  pixel  is  defined  as  noise  if and only if this pixel is a maximum or minimum
              within the pixel window.

              Use radius to specify the width of the neighborhood.

              Use +noise followed by a noise type to add noise to  an  image.   The  noise  added
              modulates the existing image pixels. Choose from these noise types:

                   Uniform
                   Gaussian
                   Multiplicative
                   Impulse
                   Laplacian
                   Poisson
                   Random (uniform distribution)

       -noop  NOOP (no option)

              The  -noop  option can be used to terminate a group of images and reset all options
              to their default values, when no other option is desired.

       -normalize
              transform image to span the full range of color values

              This is a contrast enhancement technique based on the image histogram.

              When computing the contrast enhancement values, the histogram edges  are  truncated
              so  that  the  majority  of  the  image  pixels  are  considered  in  the constrast
              enhancement, and outliers (e.g. random noise or minute details) are  ignored.   The
              default  is  that 0.1 percent of the histogram entries are ignored.  The percentage
              of the histogram to ignore may be specified by  using  the  -set  option  with  the
              histogram-threshold  parameter  similar to -set histogram-threshold 0.01 to specify
              0.01 percent.  Use 0 percent to use the entire histogram, with possibly  diminished
              contrast enhancement.

       -opaque <color>
              change this color to the pen color within the image

              The  color  is  specified  using  the format described under the -fill option.  The
              color is replaced if it is identical to the target color, or close  enough  to  the
              target color in a 3D space as defined by the Euclidean distance specified by -fuzz.

              See -fill and -fuzz for more details.

       -operator channel operator rvalue[%]
              apply a mathematical, bitwise, or value operator to an image channel

              Apply  a  low-level  mathematical,  bitwise,  or value operator to a selected image
              channel or all image channels. Operations which  result  in  negative  results  are
              reset  to  zero, and operations which overflow the available range are reset to the
              maximum possible value.

              Select a channel from: Red, Green, Blue, Opacity,  Matte,  Cyan,  Magenta,  Yellow,
              Black,  All,  or Gray. All only modifies the color channels and does not modify the
              Opacity channel. Except for the threshold operators, All operates on  each  channel
              independently so that operations are on a per-channel basis.

              Gray  treats the color channels as a grayscale intensity and performs the requested
              operation on the equivalent pixel intensity so the result is a gray image.   Select
              an  operator from Add, And, Assign, Depth, Divide, Gamma, Negate, LShift, Log, Max,
              Min, Multiply, Or, Pow, RShift, Subtract,  Threshold,  Threshold-White,  Threshold-
              White-Negate,  Threshold-Black, Threshold-Black-Negate, Xor, Noise-Gaussian, Noise-
              Impulse, Noise-Laplacian, Noise-Multiplicative,  Noise-Poisson,  Noise-Random,  and
              Noise-Uniform.

              Rvalue  may  be any floating point or integer value. Normally rvalue will be in the
              range of 0 to MaxRGB, where MaxRGB is the largest quantum value  supported  by  the
              GraphicsMagick  build (255, 65535, or 4294967295) but values outside this range are
              useful for some arithmetic operations.  Arguments to logical or bit-wise operations
              are  rounded  to a positive integral value prior to use. If a percent (%) symbol is
              appended to the argument, then the argument has a range of 0 to 100 percent.

              The following is a description of the operators:

               Add

                    Result is rvalue added to channel value.

               And

                    Result is the logical AND of rvalue with channel value.

               Assign

                    Result is rvalue.

               Depth

                    Result is channel value adjusted so that it may be (approximately) stored  in
                    the specified number of bits without additional loss.

               Divide

                    Result is channel value divided by rvalue.

               Gamma

                    Result is channel value gamma adjusted by rvalue.

               LShift

                    Result is channel value bitwise left shifted by rvalue bits.

               Log

                    Result is computed as log(value*rvalue+1)/log(rvalue+1).

               Max

                    Result is assigned to rvalue if rvalue is greater than value.

               Min

                    Result is assigned to rvalue if rvalue is less than value.

               Multiply

                    Result is channel value multiplied by rvalue.

               Negate

                    Result  is inverse of channel value (like a film negative). An rvalue must be
                    supplied but is currently not used. Inverting the image twice results in  the
                    original image.

               Or

                    Result is the logical OR of rvalue with channel value.

               Pow

                    Result  is computed as pow(value,rvalue). Similar to Gamma except that rvalue
                    is not inverted.

               RShift

                    Result is channel value bitwise right shifted by rvalue bits.

               Subtract

                    Result is channel value minus rvalue.

               Threshold

                    Result is maximum (white) if channel value is greater than rvalue, or minimum
                    (black) if it is less than or equal to rvalue. If all channels are specified,
                    then thresholding is done based on computed pixel intensity.

               Threshold-white

                    Result is maximum (white) if channel value is  greater  than  rvalue  and  is
                    unchanged  if  it is less than or equal to rvalue. This can be used to remove
                    apparent noise from the bright  parts  of  an  image.  If  all  channels  are
                    specified, then thresholding is done based on computed pixel intensity.

               Threshold-White-Negate

                    Result  is  set  to  black  if  channel  value  is greater than rvalue and is
                    unchanged if it is less  than  or  equal  to  rvalue.  If  all  channels  are
                    specified, then thresholding is done based on computed pixel intensity.

               Threshold-black

                    Result  is  minimum  (black) if channel value is less than than rvalue and is
                    unchanged if it is greater than or equal to  rvalue.  This  can  be  used  to
                    remove  apparent  noise  from the dark parts of an image. If all channels are
                    specified, then thresholding is done based on computed pixel intensity.

               Threshold-Black-Negate

                    Result is set to white if channel value is  less  than  than  rvalue  and  is
                    unchanged  if  it  is  greater  than  or equal to rvalue. If all channels are
                    specified, then thresholding is done based on computed pixel intensity.

               Xor

                    Result is the logical XOR  of  rvalue  with  channel  value.  An  interesting
                    property  of  XOR  is that performing the same operation twice results in the
                    original value.

               Noise-Gaussian

                    Result is the current channel value modulated with gaussian  noise  according
                    to the intensity specified by rvalue.

               Noise-Impulse

                    Result is the current channel value modulated with impulse noise according to
                    the intensity specified by rvalue.

               Noise-Laplacian

                    Result is the current channel value modulated with laplacian noise  according
                    to the intensity specified by rvalue.

               Noise-Multiplicative

                    Result  is  the  current channel value modulated with multiplicative gaussian
                    noise according to the intensity specified by rvalue.

               Noise-Poisson

                    Result is the current channel value modulated with poisson noise according to
                    the intensity specified by rvalue.

               Noise-Random

                    Result   is   the  current  channel  value  modulated  with  random  (uniform
                    distribution) noise according to the  intensity  specified  by  rvalue.   The
                    initial noise intensity (rvalue=1.0) is the range of one pixel quantum span.

               Noise-Uniform

                    Result  is  the  channel  value  with  uniform noise applied according to the
                    intensity specified by rvalue.

               As an example, the Assign operator  assigns  a  fixed  value  to  a  channel.  For
               example, this command sets the red channel to the mid-range value:

                   gm convert in.bmp -operator red assign "50%" out.bmp

               The following applies 50% thresholding to the image and returns a gray image:

                   gm convert in.bmp -operator gray threshold "50%" out.bmp

       -ordered-dither <channeltype> <NxN>
              ordered dither the image

              The  channel  or  channels  specified  in  the  channeltype argument are reduced to
              binary, using an ordered dither  method.  The  choices  for  channeltype  are  All,
              Intensity, Red, Green, Blue, Cyan, Magenta, Yellow, Black, and Opacity

              When  channeltype  is  "All",  the color samples are dithered into a gray level and
              then that gray level is stored  in  the  three  color  channels.   Separately,  the
              opacity  channel  is  dithered  into a bilevel opacity value which is stored in the
              opacity channel.

              When channeltype  is  "Intensity",  only  the  color  samples  are  dithered.  When
              channeltype  is  "opacity" or "matte", only the opacity channel is dithered. When a
              color channel is specified, only that channel is dithered.

              The choices for N are 2 through 7. The image is divided into NxN pixel  tiles.   In
              each  tile,  some  or  all pixels are turned to white depending on their intensity.
              For each N, (N**2)+1 levels of gray can be represented.  For N == 2, 3, or  4,  the
              pixels  are  turned  to  white in an order that maximizes dispersion (i.e., reduces
              granularity), while for N == 5, 6, and 7, they are turned to white in an order that
              creates  a  roughly  circular black blob in the middle of each tile.  An attractive
              "half-tone" looking image can be obtained by first rotating the image  45  degrees,
              performing  a  5x5  ordered-dither operation, then rotating it back to the original
              orientation and cropping to the original image dimensions.  If the  original  image
              is  gamma-encoded,  it is adviseable to convert it to linear intensity first, e.g.,
              with the "-gamma 0.45455" option.

       -output-directory <directory>
              output files to directory

              Use -output-directory to specify a directory under which to write the output files.
              Normally  mogrify overwrites the input files, but with this option the output files
              may be written to a different directory tree so that the input files are preserved.
              The algorithm used preserves all of the input path specification in the output path
              so that the  user-specified  input  path  (including  any  sub-directory  part)  is
              appended  to the output path. If the input file lacks an extension, then a suitable
              extension is automatically added to the output file.  The user is  responsible  for
              creating  the output directory specified as an argument, but subdirectories will be
              created as needed if the -create-directories option is supplied.  This  option  may
              be  used  to  apply  transformations  on  files  from  one  directory and write the
              transformed  files  to  a  different  directory.   In  conjunction  with   -create-
              directories,  this option is designed to support transforming whole directory trees
              of files provided that the relative path of the input file is included as part  the
              list of filenames.

       -orient <orientation>
              Set the image orientation attribute

              Sets   the  image  orientation  attribute.   The  image  orientation  attribute  is
              compatible with the TIFF orientation tag (and the EXIF orientation tag).   Accepted
              values   are   undefined,  TopLeft,  TopRight,  BottomRight,  BottomLeft,  LeftTop,
              RightTop, RightBottom, LeftBottom, and  hyphenated  versions  thereof  (e.g.  left-
              bottom).   Please note that GraphicsMagick does not include an EXIF editor so if an
              EXIF profile is written to the output image, the value in the  EXIF  profile  might
              not  match the image.  It is possible for an image file to indicate its orientation
              in several different ways simultaneously.

       -page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
              size and location of an image canvas

              Use this option to specify the dimensions of the PostScript page in dots  per  inch
              or a TEXT page in pixels. The choices for a PostScript page are:

                   11x17         792  1224
                   Ledger       1224   792
                   Legal         612  1008
                   Letter        612   792
                   LetterSmall   612   792
                   ArchE        2592  3456
                   ArchD        1728  2592
                   ArchC        1296  1728
                   ArchB         864  1296
                   ArchA         648   864
                   A0           2380  3368
                   A1           1684  2380
                   A2           1190  1684
                   A3            842  1190
                   A4            595   842
                   A4Small       595   842
                   A5            421   595
                   A6            297   421
                   A7            210   297
                   A8            148   210
                   A9            105   148
                   A10            74   105
                   B0           2836  4008
                   B1           2004  2836
                   B2           1418  2004
                   B3           1002  1418
                   B4            709  1002
                   B5            501   709
                   C0           2600  3677
                   C1           1837  2600
                   C2           1298  1837
                   C3            918  1298
                   C4            649   918
                   C5            459   649
                   C6            323   459
                   Flsa          612   936
                   Flse          612   936
                   HalfLetter    396   612

              For  convenience  you  can  specify the page size by media (e.g. A4, Ledger, etc.).
              Otherwise, -page behaves much like -geometry (e.g.  -page letter+43+43>).

              This option is also used to place subimages when writing to  a  multi-image  format
              that  supports  offsets,  such  as  GIF89  and MNG.  When used for this purpose the
              offsets are always  measured from the top left corner of the  canvas  and  are  not
              affected   by   the  -gravity  option.   To  position  a  GIF  or  MNG  image,  use
              -page{+-}<x>{+-}<y> (e.g. -page +100+200).  When writing to a  MNG  file,  a  -page
              option  appearing  ahead  of the first image in the sequence with nonzero width and
              height defines the width and height values that are  written  in  the  MHDR  chunk.
              Otherwise,  the  MNG  width  and  height  are  computed  from the bounding box that
              contains all images in the sequence.  When writing a GIF89 file, only the  bounding
              box method is used to determine its dimensions.

              For  a  PostScript page, the image is sized as in -geometry and positioned relative
              to the lower left hand corner of the page by {+-}<xoffset>{+-}<y offset>. Use -page
              612x792>,  for  example,  to  center  the  image within the page. If the image size
              exceeds the PostScript page, it is reduced to fit the page.   The  default  gravity
              for  the  -page  option  is  NorthWest,  i.e., positive x and y offset are measured
              rightward and downward from the top left corner of the page,  unless  the  -gravity
              option is present with a value other than NorthWest.

              The default page dimensions for a TEXT image is 612x792.

              This option is used in concert with -density.

              Use +page to remove the page settings for an image.

       -paint <radius>
              simulate an oil painting

              Each  pixel is replaced by the most frequent color in a circular neighborhood whose
              width is specified with radius.

       -pause <seconds>
              pause between animation loops [animate]

              Pause for the specified number of seconds before repeating the animation.

       -pause <seconds>
              pause between snapshots [import]

              Pause for the specified number of seconds before taking the next snapshot.

       -pen <color>
              (This option has been replaced by the -fill option)

       -ping  efficiently determine image characteristics

              Use this option to disable reading the image pixels so that  image  characteristics
              such  as the image dimensions may be obtained very quickly. For identify, use +ping
              to force reading the image pixels so that the pixel read rate may  be  included  in
              the displayed information.

       -pointsize <value>
              pointsize of the PostScript, X11, or TrueType font

       -preview <type>
              image preview type

              Use this option to affect the preview operation of an image (e.g.  convert file.png
              -preview Gamma Preview:gamma.png). Choose from these previews:

                   Rotate
                   Shear
                   Roll
                   Hue
                   Saturation
                   Brightness
                   Gamma
                   Spiff
                   Dull
                   Grayscale
                   Quantize
                   Despeckle
                   ReduceNoise
                   AddNoise
                   Sharpen
                   Blur
                   Threshold
                   EdgeDetect
                   Spread
                   Shade
                   Raise
                   Segment
                   Solarize
                   Swirl
                   Implode
                   Wave
                   OilPaint
                   CharcoalDrawing
                   JPEG

              The default preview is JPEG.

       -process <command>
              process a sequence of images using a process module

              The command argument has the form module=arg1,arg2,arg3,...,argN  where  module  is
              the  name  of the module to invoke (e.g. "Analyze") and arg1,arg2,arg3,...,argN are
              an arbitrary number of arguments to pass to the process module.   The  sequence  of
              images is terminated by the appearance of any option.

              If  the  -process  option  appears  after  all  of the input images, all images are
              processed.

              For example:

                   gm convert logo: -process Analyze= \
                     -format "%[BrightnessMean],%[BrightnessStddev]" info:-
                   51952,23294

       -profile <filename>
              add ICM, IPTC, or generic profile  to image

              -profile filename adds an ICM (ICC color management), IPTC
              (newswire information), or a generic (including Exif) profile to the image

              Use +profile icm, +profile iptc, or
              +profile profile_name to remove the respective profile.
              Multiple profiles may be listed, separated by commas. Profiles may be
              excluded from subsequent listed matches by preceding their name with
              an exclamation point.  For example, +profile '!icm,*' strips
              all profiles except for the ICM profile.  Use identify
              -verbose to find out what profiles are in the image file.  Use
              +profile "*" to remove all profiles.
              Writing the image to a format that does not support profiles will
              of course also cause all profiles to be removed.  The JPEG and PNG
              formats will store any profiles that have been read and not removed.
              In JPEG they are stored in APP1 markers, and in PNG they are stored
              as hex-coded binary in compressed zTXt chunks, except for the iCC
              chunk which is stored in the iCCP chunk.

              To extract a profile, the -profile option is not used.  Instead,
              simply write the file to an image
              format such as APP1, 8BIM, ICM, or IPTC.

              For example, to extract the Exif data (which is stored in JPEG files
              in the APP1 profile), use

                  gm convert cockatoo.jpg exifdata.app1
              Note that GraphicsMagick does not attempt to update any profile to reflect  changes
              made  to the image, e.g., rotation from portrait to landscape orientation, so it is
              possible that the preserved profile may contain invalid data.

       -preserve-timestamp
              preserve the original timestamps of the file

              Use this option to preserve the original modification and access timestamps of  the
              file, even if it has been modified.

       +progress
              disable progress monitor and busy cursor

              By  default, when an image is displayed, a progress monitor bar is shown in the top
              left corner of an existing image display window, and the current cursor is replaced
              with  an  hourglass  cursor. Use +progress to disable the progress monitor and busy
              cursor during display operations.  While the progress monitor is disabled  for  all
              operations, the busy cursor continues to be enabled for non-display operations such
              as image processing. This option is useful for non-interactive display  operations,
              or when a "clean" look is desired.

       -quality <value>
              JPEG/MIFF/PNG/TIFF compression level
               For  the  JPEG  and  MPEG  image  formats,  quality is 0 (lowest image quality and
              highest compression) to 100 (best quality but  least  effective  compression).  The
              default  quality is 75.  Use the -sampling-factor option to specify the factors for
              chroma downsampling.  To use the same quality value  as  that  found  by  the  JPEG
              decoder, use the -define jpeg:preserve-settings flag.

              For  the  MIFF  image  format,  and  the  TIFF  format while using ZIP compression,
              quality/10  is  the  zlib  compression  level,  which  is  0  (worst  but   fastest
              compression)  to  9  (best  but slowest). It has no effect on the image appearance,
              since the compression is always lossless.

              For the JPEG-2000 image format, quality is mapped using a  non-linear  equation  to
              the  compression  ratio required by the Jasper library. This non-linear equation is
              intended to loosely approximate the quality provided by the  JPEG  v1  format.  The
              default  quality  value  75  results in a request for 16:1 compression. The quality
              value 100 results in a request for non-lossy compression.

              For the MNG and PNG image formats, the quality  value  sets  the  zlib  compression
              level  (quality / 10) and filter-type (quality % 10). Compression levels range from
              0 (fastest compression) to 100 (best but slowest). For  compression  level  0,  the
              Huffman-only  strategy  is  used,  which  is  fastest but not necessarily the worst
              compression.

              If filter-type is 4 or less, the specified filter-type is used for all scanlines:

                   0: none
                   1: sub
                   2: up
                   3: average
                   4: Paeth

              If filter-type is 5, adaptive filtering is used when quality is greater than 50 and
              the image does not have a color map, otherwise no filtering is used.

              If  filter-type  is  6,  adaptive  filtering with minimum-sum-of-absolute-values is
              used.

              Only if the output is MNG, if filter-type is 7, the LOCO color  transformation  and
              adaptive filtering with minimum-sum-of-absolute-values are used.

              The default is quality is 75, which means nearly the best compression with adaptive
              filtering.  The quality setting has no effect on the  appearance  of  PNG  and  MNG
              images, since the compression is always lossless.

              For further information, see the PNG specification.

              When  writing  a  JNG image with transparency, two quality values are required, one
              for the main image and one  for  the  grayscale  image  that  conveys  the  opacity
              channel.   These  are  written  as a single integer equal to the main image quality
              plus 1000 times the opacity quality.  For example, if you want to  use  quality  75
              for the main image and quality 90 to compress the opacity data, use -quality 90075.

              For  the PNM family of formats (PNM, PGM, and PPM) specify a quality factor of zero
              in order to obtain the ASCII variant of the format. Note that -compress  none  used
              to  be  used  to  trigger ASCII output but provided the opposite result of what was
              expected as compared with other formats.

              For the TIFF format, the JPEG, WebP,  Zip,  and  Zstd  compression  algorithms  are
              influenced by the quality value.  JPEG and WebP provide lossy compression so higher
              quality produces a larger file with less degradation.  The Zip and Zstd compression
              algorithms  (and  WebP  in  lossless  mode) are lossless and for these algorithms a
              higher ´quality' means to work harder to  produce  a  smaller  file,  but  with  no
              difference in image quality.

       -raise <width>x<height>
              lighten or darken image edges

              This will create a 3-D effect. See -geometry for details details about the geometry
              specification. Offsets are not used.

              Use -raise to create a raised effect, otherwise use +raise.

       -random-threshold <channeltype> <LOWxHIGH>
              random threshold the image

              The channel or channels specified in the  <channeltype>  argument  are  reduced  to
              binary,  using  an  random-threshold  method.  The choices for channeltype are All,
              Intensity, Red, Green, Blue, Cyan, Magenta, Yellow, Black, and Opacity

              When channeltype is "All", the color samples are thresholded into a  graylevel  and
              then that gray level is stored in the three color channels. Separately, the opacity
              channel is thresholded into a bilevel opacity value which is stored in the  opacity
              channel.  For each pixel, a new random number is used to establish the threshold to
              be used. The threshold never exceeds the specified maximum (HIGH) and is never less
              than the specified minimum (LOW).

              When  channeltype  is  "intensity",  only  the  color samples are thresholded. When
              channeltype is "opacity" or "matte", only the opacity channel is  thresholded.  The
              other named channels only threshold the associated channel.

       -recolor <matrix>
              apply a color translation matrix to image channels

              A  user  supplied  color translation matrix (expressed as a text string) is used to
              translate/blend the image channels based on weightings in a supplied  matrix  which
              may  be  of  order  3  (color channels only), 4 (color channels plus opacity), or 5
              (color channels plus opacity and offset).  Values in  the  columns  of  the  matrix
              (red,  green,  blue,  opacity)  are  used  as multipliers with the existing channel
              values and added together according to the rows of the matrix.  Matrix  values  are
              floating  point  and  may  be  negative.   The  offset  column (column 5) is purely
              additive and is scaled such that 0.0 to 1.0 represents the  maximum  quantum  range
              (but  values  are  not  limited  to this range). The math for the color translation
              matrix is similar to that used by Adobe Flash except that the offset is  scaled  to
              1.0  (divide  Flash  offset by 255 for use with GraphicsMagick) so that the results
              are independent of quantum depth.

              An identity matrix exists for each matrix order which results in no change  to  the
              image.   The  translation  matrix  should be based on an alteration of the identity
              matrix.

              Identity matrix of order 3

                1 0 0
                0 1 0
                0 0 1

              which may be formatted into a convenient  matrix  argument  similar  to  (comma  is
              treated as white space):

                -recolor "1 0 0, 0 1 0, 0 0 1"

              Identity matrix of order 4

                1 0 0 0
                0 1 0 0
                0 0 1 0
                0 0 0 1

              Identity  matrix  of order 5.  The last row is required to exist for the purpose of
              parsing, but is otherwise not used.

                1 0 0 0 0
                0 1 0 0 0
                0 0 1 0 0
                0 0 0 1 0
                0 0 0 0 1

              As an example, an image wrongly in BGR channel order may be converted to RGB  using
              this matrix (blue->red, red->blue):

                0 0 1
                0 1 0
                1 0 0

              and  an  RGB  image  using standard Rec.709 primaries may be converted to grayscale
              using this matrix of standard weighting factors:

                0.2126 0.7152 0.0722
                0.2126 0.7152 0.0722
                0.2126 0.7152 0.0722

              and contrast may be reduced by scaling down by 80% and adding a 10% offset:

                0.8 0.0 0.0 0.0 0.1
                0.0 0.8 0.0 0.0 0.1
                0.0 0.0 0.8 0.0 0.1
                0.0 0.0 0.0 0.8 0.1
                0.0 0.0 0.0 0.0 1.0

       -red-primary <x>,<y>
              red chromaticity primary point

       -region <width>x<height>{+-}<x>{+-}<y>
              apply options to a portion of the image

              The x and y offsets are treated in the same manner as in -crop.

       -remote
              perform a X11 remote operation

              The -remote command sends a command to a "gm display"  or  "gm  animate"  which  is
              already  running.  The only command recognized at this time is the name of an image
              file to load. This capability is very useful to load new images without needing  to
              restart  GraphicsMagick  (e.g.  for  a  slide-show  or to use GraphicsMagick as the
              display engine for a different GUI). Also see the +progress option  for  a  way  to
              disable progress indication for a clean look while loading new images.

       -render
              render vector operations

              Use +render to turn off rendering vector operations. This is useful when saving the
              result to vector formats such as MVG or SVG.

       -repage  <width>x<height>+xoff+yoff[!]
              Adjust image page offsets

              Adjust the current image  page  canvas  and  position  based  on  a  relative  page
              specification.   This option may be used to change the location of a subframe (e.g.
              part of an animation) prior to  composition.   If  the  geometry  specification  is
              absolute  (includes  a '!'), then the offset adjustment is absolute and there is no
              adjustment to page width and height, otherwise the page width and height values are
              also  adjusted based on the current image dimensions.  Use +repage to set the image
              page offsets to default.

       -resample <horizontal>x<vertical>
              Resample image to specified horizontal and vertical resolution

              Resize the image so that its rendered size remains the same as the original at  the
              specified  target  resolution.  Either  the  current  image resolution units or the
              previously set with -units are used to interpret the argument. For  example,  if  a
              300  DPI  image renders at 3 inches by 2 inches on a 300 DPI device, when the image
              has been resampled to 72 DPI, it will render at 3 inches by 2 inches on  a  72  DPI
              device.   Note that only a small number of image formats (e.g. JPEG, PNG, and TIFF)
              are capable of storing the image resolution. For formats which do  not  support  an
              image  resolution,  the  original  resolution  of  the  image must be specified via
              -density on the command line prior to specifying the resample resolution.

              Note that Photoshop stores and obtains image resolution from a proprietary embedded
              profile. If this profile exists in the image, then Photoshop will continue to treat
              the image using its former resolution, ignoring the image resolution  specified  in
              the standard file header.

              Some image formats (e.g. PNG) require use of metric or english units so even if the
              original image used a particular unit system, if it is saved to a different  format
              prior  to  resampling,  then  it may be necessary to specify the desired resolution
              units using -units since the original units may have been lost. In other words,  do
              not  assume that the resolution units are restored if the image has been saved to a
              file.

       -resize <width>x<height>{%}{@}{!}{<}{>}
              resize an image

              This is an alias for the -geometry option and it behaves in the same manner. If the
              -filter option precedes the -resize option, the specified filter is used.

              There are some exceptions:

              When  used  as a composite option, -resize conveys the preferred size of the output
              image, while -geometry conveys the size and placement of the composite image within
              the main image.

              When  used  as a montage option, -resize conveys the preferred size of the montage,
              while -geometry conveys information about the tiles.

       -roll {+-}<x>{+-}<y>
              roll an image vertically or horizontally

              See -geometry for details the geometry specification.  The x and y offsets are  not
              affected by the -gravity option.

              A  negative  x  offset rolls the image left-to-right. A negative y offset rolls the
              image top-to-bottom.

       -rotate <degrees>{<}{>}
              rotate the image

              Positive angles rotate the image in a clockwise  direction  while  negative  angles
              rotate counter-clockwise.

              Use  >  to  rotate  the  image only if its width exceeds the height.  < rotates the
              image only if its width is less than  the  height.  For  example,  if  you  specify
              -rotate  "-90>"  and the image size is 480x640, the image is not rotated.  However,
              if the image is 640x480, it is rotated by -90 degrees.  If you use > or <,  enclose
              it  in  quotation  marks  to  prevent  it  from  being  misinterpreted  as  a  file
              redirection.

              Empty triangles left over from rotating the image are filled with the color defined
              as  background  (class  backgroundColor).   The color is specified using the format
              described under the -fill option.

       -sample <geometry>
              scale image using pixel sampling

              See -geometry for details about the geometry specification.   -sample  ignores  the
              -filter  selection  if  the  -filter option is present.  Offsets, if present in the
              geometry string, are ignored, and the -gravity option has no effect.

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

              This option specifies the sampling factors to be used by the DPX,  JPEG,  MPEG,  or
              YUV  encoders  for chroma downsampling. The sampling factor must be specified while
              reading the raw YUV format since it is not preserved in the file header.  Industry-
              standard video subsampling notation such as "4:2:2" may also be used to specify the
              sampling factors. "4:2:2" is equivalent to a specification of "2x1"

              The JPEG decoder obtains the original sampling factors (and quality settings)  when
              a  JPEG file is read. To re-use the original sampling factors (and quality setting)
              when JPEG is output, use the -define jpeg:preserve-settings flag.

       -scale <geometry>
              scale the image.

              See -geometry for details about the geometry specification.  -scale uses a simpler,
              faster  algorithm,  and  it  ignores the -filter selection if the -filter option is
              present.  Offsets, if present in the geometry string, are ignored, and the -gravity
              option has no effect.

       -scene <value>
              set scene number

              This  option  sets  the  scene  number  of  an image or the first image in an image
              sequence.

       -scenes <value-value>
              range of image scene numbers to read

              Each image in the range is read with the filename followed by a period (.) and  the
              decimal  scene  number.   You can change this behavior by embedding a %d, %0Nd, %o,
              %0No, %x, or %0Nx printf format specification in the file name. For example,

                  gm montage -scenes 5-7 image.miff montage.miff

              makes a montage of files image.miff.5, image.miff.6, and image.miff.7, and

                  gm animate -scenes 0-12 image%02d.miff

              animates files image00.miff, image01.miff, through image12.miff.

       -screen
              specify the screen to capture

              This option indicates that the GetImage request used to obtain the image should  be
              done  on  the  root  window, rather than directly on the specified window.  In this
              way, you can obtain pieces of other windows that overlap the specified window,  and
              more  importantly,  you  can  capture  menus  or  other popups that are independent
              windows but appear over the specified window.

       -set <attribute> <value>
              set an image attribute

              Set a named image attribute.  The attribute  is  set  on  the  current  (previously
              specified on command line) image.

       +set <attribute>
              unset an image attribute

              Unset  a  named  image  attribute.   The  attribute  is  removed  from  the current
              (previously specified on command line) image.

       -segment <cluster threshold>x<smoothing threshold>
              segment an image

              Segment  an  image  by  analyzing  the  histograms  of  the  color  components  and
              identifying units that are homogeneous with the fuzzy c-means technique.

              Segmentation is a very useful fast and and approximate color quantization algorithm
              for scanned printed pages or scanned cartoons. It may also be  used  as  a  special
              effect.  Specify  cluster  threshold as the minimum percentage of total pixels in a
              cluster before it is considered valid.  For huge images  containing  small  detail,
              this  may  need  to  be a tiny fraction of a percent (e.g. 0.015) so that important
              detail is not lost.  Smoothing threshold eliminates noise in the second  derivative
              of  the  histogram.  As  the  value  is increased, you can expect a smoother second
              derivative. The default is 1.5. Add the -verbose option to see a  dump  of  cluster
              statistics given the parameters used. The statistics may be used as a guide to help
              fine tune the options.

       -shade <azimuth>x<elevation>
              shade the image using a distant light source

              Specify azimuth and elevation as the position of the light source.  Use  +shade  to
              return the shading results as a grayscale image.

       -shadow <radius>{x<sigma>}
              shadow the montage

       -shared-memory
              use shared memory

              This  option  specifies whether the utility should attempt to use shared memory for
              pixmaps.  GraphicsMagick must be compiled  with  shared  memory  support,  and  the
              display  must  support  the  MIT-SHM extension.  Otherwise, this option is ignored.
              The default is True.

       -sharpen <radius>{x<sigma>}
              sharpen the image

              Use a Gaussian operator of the given radius and standard deviation (sigma).

       -shave <width>x<height>{%}
              shave pixels from the image edges

              Specify the width of the region to be removed from both sides of the image and  the
              height of the regions to be removed from top and bottom.

       -shear <x degrees>x<y degrees>
              shear the image along the X or Y axis

              Use the specified positive or negative shear angle.

              Shearing  slides  one  edge  of  an  image  along  the  X  or  Y  axis,  creating a
              parallelogram. An X direction shear slides an edge along the  X  axis,  while  a  Y
              direction  shear  slides  an  edge  along  the  Y  axis. The amount of the shear is
              controlled by a shear angle. For X direction shears, x degrees is measured relative
              to the Y axis, and similarly, for Y direction shears y degrees is measured relative
              to the X axis.

              Empty triangles left over from shearing the image are filled with the color defined
              as  background  (class  backgroundColor).   The color is specified using the format
              described under the -fill option.

       -silent
              operate silently

       -size <width>x<height>{+offset}
              width and height of the image

              Use this option to specify the width and height of raw images whose dimensions  are
              unknown such as GRAY, RGB, or CMYK. In addition to width and height, use -size with
              an offset to skip any header information in the image or tell the number of  colors
              in a MAP image file, (e.g. -size 640x512+256).

              For Photo CD images, choose from these sizes:

                   192x128
                   384x256
                   768x512
                   1536x1024
                   3072x2048

              Finally,  use this option to choose a particular resolution layer of a JBIG or JPEG
              image (e.g. -size 1024x768).

       -snaps <value>
              number of screen snapshots

              Use this option to grab more than one image from the X server screen, to create  an
              animation sequence.

       -solarize <factor>
              negate all pixels above the threshold level

              Specify factor as the percent threshold of the intensity (0 - 99.9%).

              This  option  produces a solarization effect seen when exposing a photographic film
              to light during the development process.

       -spread <amount>
              displace image pixels by a random amount

              Amount defines the size of the neighborhood around each pixel to choose a candidate
              pixel to swap.

       -stegano <offset>
              hide watermark within an image

              Use an offset to start the image hiding some number of pixels from the beginning of
              the image.  Note this offset and the image size.  You will need this information to
              recover the steganographic image (e.g. display -size 320x256+35 stegano:image.png).

       -stereo
              composite two images to create a stereo anaglyph

              The  left  side of the stereo pair is saved as the red channel of the output image.
              The right side is saved  as  the  green  channel.   Red-green  stereo  glasses  are
              required to properly view the stereo image.

       -strip remove all profiles and text attributes from the image

              All  embedded  profiles  and  text attributes are stripped from the image.  This is
              useful for images used for the web, or when output files need to  be  as  small  as
              possible

              Be  careful  not  to  use  this  option  to  remove  author, copyright, and license
              information that you are required to retain when redistributing an image.

       -stroke <color>
              color to use when stroking a graphic primitive

              The color is specified using the format described under the -fill option.

              See -draw for further details.

       -strokewidth <value>
              set the stroke width

              See -draw for further details.

       -swirl <degrees>
              swirl image pixels about the center

              Degrees defines the tightness of the swirl.

       -text-font <name>
              font for writing fixed-width text

              Specifies the name of the  preferred  font  to  use  in  fixed  (typewriter  style)
              formatted text.  The default is 14 point Courier.

              You  can  tag  a font to specify whether it is a PostScript, TrueType, or X11 font.
              For example, Courier.ttf is a TrueType font and x:fixed is X11.

       -texture <filename>
              name of texture to tile onto the image background

       -threshold <value>{%}
              threshold the image

              Modify the image such that any pixel sample with an intensity  value  greater  than
              the  threshold  is assigned the maximum intensity (white), or otherwise is assigned
              the minimum intensity (black). If a percent prefix is applied, then  the  threshold
              is a percentage of the available range.

              To efficiently create a black and white image from a color image, use

                  gm convert -threshold 50% in.png out.png

              The  optimum  threshold  value  depends  on  the  nature of the image.  In order to
              threshold individual channels, use the -operator subcommand  with  it's  Threshold,
              Threshold-White, or Threshold-Black options.

       -thumbnail <width>x<height>{%}{@}{!}{<}{>}
              resize an image (quickly)

              The  -thumbnail command resizes the image as quickly as possible, with more concern
              for speed than resulting image quality.  Regardless, resulting image quality should
              be  acceptable  for  many  uses.   It  is primarily intended to be used to generate
              smaller versions of the image, but may also be used  to  enlarge  the  image.   The
              -thumbnail  geometry  argument  observes  the  same syntax and rules as it does for
              -resize.

       -tile <filename>
              tile image when filling a graphic primitive

       -tile <geometry>
              layout of images [montage]

       -title <string>
              assign title to displayed image [animate, display, montage]

              Use this option to assign a specific title to the image. This is  assigned  to  the
              image  window  and  is typically displayed in the window title bar.  Optionally you
              can include the image filename, type, width, height,  Exif  data,  or  other  image
              attribute  by  embedding  special  format  characters  described  under the -format
              option.

              For example,

                   -title "%m:%f %wx%h"

              produces an image title of MIFF:bird.miff 512x480 for an image titled bird.miff and
              whose width is 512 and height is 480.

       -transform
              transform the image

              This option applies the transformation matrix from a previous -affine option.

                  gm convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg

       -transparent <color>
              make this color transparent within the image

              The color is specified using the format described under the -fill option.

       -treedepth <value>
              tree depth for the color reduction algorithm

              Normally,  this integer value is zero or one. A value of zero or one causes the use
              of an optimal tree depth for the color reduction algorithm

              An optimal depth generally allows the best representation of the source image  with
              the  fastest  computational  speed  and  the  least amount of memory.  However, the
              default depth is inappropriate for some images. To assure the best  representation,
              try values between 2 and 8 for this parameter.  Refer to quantize for more details.

              The  -colors  or  -monochrome  option, or writing to an image format which requires
              color reduction, is required for this option to take effect.

       -trim  trim an image

              This option removes any edges that are exactly the same color as the corner pixels.
              Use  -fuzz  to make -trim remove edges that are nearly the same color as the corner
              pixels.

       -type <type>
              the image type

              Choose from: Bilevel, Grayscale, Palette, PaletteMatte, TrueColor,  TrueColorMatte,
              ColorSeparation, ColorSeparationMatte, or Optimize.

              Normally,  when  a format supports different subformats such as bilevel, grayscale,
              palette, truecolor, and truecolor+alpha, the encoder will try to choose a  suitable
              subformat  based on the nature of the image. The -type option may be used to tailor
              the output subformat. By default the output subformat is based on readily available
              image information and is usually similar to the input format.

              Specify  -type  Optimize in order to enable inspecting all pixels (if necessary) in
              order to find the most efficient subformat. Inspecting all of  the  pixels  may  be
              slow  for very large images, particularly if they are stored in a disk cache. If an
              RGB image contains only gray  pixels,  then  every  pixel  in  the  image  must  be
              inspected in order to decide that the image is actually grayscale!

              Sometimes a specific subformat is desired. For example, to force a JPEG image to be
              written in TrueColor RGB format even though only gray pixels are present, use

                  gm convert bird.pgm -type TrueColor bird.jpg

              Similarly, using -type TrueColorMatte will force the  encoder  to  write  an  alpha
              channel   even   though  the  image  is  opaque,  if  the  output  format  supports
              transparency.

              Some pseudo-formats (e.g. the XC format) will respect  the  requested  type  if  it
              occurs  previously on the command line.  For example, to obtain a DirectClass solid
              color canvas image rather than PsuedoClass, use

                  gm convert -size 640x480 -type TrueColor xc:red red.miff

              Likewise, specify -type Bilevel, Grayscale, TrueColor, or TrueColorMatte  prior  to
              reading  a  Postscript  (or  PDF file) in order to influence the type of image that
              Ghostcript  returns.  Reading  performance  will  be  dramatically   improved   for
              black/white  Postscript if Bilevel is specified, and will be considerably faster if
              Grayscale is specified.

       -update <seconds>
               detect when image file is modified and redisplay.

              Suppose that while you are displaying an image the file that is currently displayed
              is  over-written.   display  will automatically detect that the input file has been
              changed and update the displayed image accordingly.

       -units <type>
              the units of image resolution

              Choose from: Undefined,  PixelsPerInch,  or  PixelsPerCentimeter.  This  option  is
              normally used in conjunction with the -density option.

       -unsharp <radius>{x<sigma>}{+<amount>}{+<threshold>}
              sharpen the image with an unsharp mask operator

              The  -unsharp  option  sharpens  an  image.  The image is convolved with a Gaussian
              operator of the  given  radius  and  standard  deviation  (sigma).  For  reasonable
              results,  radius  should be larger than sigma. Use a radius of 0 to have the method
              select a suitable radius.

              The parameters are:

               radius

                    The radius of the Gaussian, in pixels, not counting the center pixel (default
                    0).

               sigma

                    The standard deviation of the Gaussian, in pixels (default 1.0).

               amount

                    The percentage of the difference between the original and the blur image that
                    is added back into the original (default 1.0).

               threshold

                    The threshold, as a fraction of MaxRGB, needed to apply the difference amount
                    (default 0.05).

       -use-pixmap
              use the pixmap

       -verbose
              print detailed information about the image

              This  information is printed: image scene number; image name; image size; the image
              class (DirectClass or PseudoClass); the total number  of  unique  colors;  and  the
              number of seconds to read and transform the image. If the image is DirectClass, the
              total number of unique colors is not displayed unless -verbose is  specified  twice
              since  it  may take quite a long time to compute, particularly for deep images.  If
              the image is PseudoClass then its pixels are defined by indexes into a colormap. If
              the  image is DirectClass then each pixel includes a complete and independent color
              specification.

              If -colors is also specified, the total  unique  colors  in  the  image  and  color
              reduction  error  values  are printed. Refer to quantize for a description of these
              values.

       -version
              print GraphicsMagick version string

       -view <string>
              FlashPix viewing parameters

       -virtual-pixel <method>
              specify contents of "virtual pixels"

              This option defines "virtual pixels" for use in operations that can  access  pixels
              outside the boundaries of an image.

              Choose from these methods:

               Constant

                    Use the image background color.

               Edge

                    Extend the edge pixel toward infinity (default).

               Mirror

                    Mirror the image.

               Tile

                    Tile the image.

               This  option  affects  operations that use virtual pixels such as -blur, -sharpen,
               -wave, etc.

       -visual <type>
              animate images using this X visual type

              Choose from these visual classes:

                   StaticGray
                   GrayScale
                   StaticColor
                   PseudoColor
                   TrueColor
                   DirectColor
                   default
                   visual id

              The X server must support the visual you choose, otherwise an error occurs.   If  a
              visual  is  not  specified, the visual class that can display the most simultaneous
              colors on the default screen is chosen.

       -watermark <brightness>x<saturation>
              percent brightness and saturation of a watermark

       -wave <amplitude>x<wavelength>
              alter an image along a sine wave

              Specify amplitude and wavelength of the wave.

       -white-point <x>,<y>
              chromaticity white point

       -white-threshold red[,green][,blue][,opacity]
              pixels above the threshold become white

              Use -white-threshold to set pixels with values above  the  specified  threshold  to
              maximum  value  (white). If only one value is supplied, or the red, green, and blue
              values are identical, then intensity thresholding is used. If the  color  threshold
              values  are  not  identical  then  channel-based  thresholding  is  used, and color
              distortion will occur. Specify a negative value (e.g. -1) if you want a channel  to
              be  ignored  but you do want to threshold a channel later in the list. If a percent
              (%) symbol is appended, then the values are treated  as  a  percentage  of  maximum
              range.

       -window <id>
              make image the background of a window

              id  can  be  a  window  id  or name.  Specify root to select X's root window as the
              target window.

              By default the image is tiled onto  the  background  of  the  target  window.    If
              backdrop  or  -geometry  are  specified,  the image is surrounded by the background
              color.  Refer to X RESOURCES for details.

              The image will not display on the root window if the image has more  unique  colors
              than  the  target  window  colormap  allows.   Use  -colors to reduce the number of
              colors.

       -window-group
              specify the window group

       -write <filename>
              write an intermediate image [convert, composite]

              The current image  is  written  to  the  specified  filename  and  then  processing
              continues  using that image. The following is an example of how several sizes of an
              image may be generated in one command (repeat as often as needed):

                  gm convert input.jpg -resize 50% -write input50.jpg \
                            -resize 25% input25.jpg

       -write <filename>
              write the image to a file [display]

              If filename already exists, you will  be  prompted  as  to  whether  it  should  be
              overwritten.

              By  default, the image is written in the format that it was read in as.  To specify
              a particular image format, prefix filename with the image type and a  colon  (e.g.,
              ps:image)  or  specify  the  image  type  as  the filename suffix (e.g., image.ps).
              Specify file as - for standard output. If file has the extension  .Z  or  .gz,  the
              file size is compressed using compress or gzip respectively. Precede the image file
              name with | to pipe to a system command.

              Use -compress to specify the type of image compression.

              The equivalent X resource for this option is writeFilename  (class  WriteFilename).
              See "X Resources", below, for details.

ENVIRONMENT

       COLUMNS
              Output  screen  width.  Used when formatting text for the screen. Many Unix systems
              keep this shell variable up to date, but it may need to be explicitly  exported  in
              order for GraphicsMagick to see it.

       DISPLAY
              X11    display    ID    (host,   display   number,   and   screen   in   the   form
              hostname:display.screen).

       HOME   Location of user's home directory. For  security  reasons,  now  only  observed  by
              "uninstalled"  builds of GraphicsMagick which do not have their location hard-coded
              or set by an installer.  When supported, GraphicsMagick searches for  configuration
              files  in  $HOME/.magick  if  the  directory  exists. See MAGICK_CODER_MODULE_PATH,
              MAGICK_CONFIGURE_PATH, and MAGICK_FILTER_MODULE_PATH if more flexibility is needed.

       MAGICK_ACCESS_MONITOR
              When set to TRUE, command line monitor mode (enabled by -monitor)  will  also  show
              files  accessed  (including  temporary  files)  and any external commands which are
              executed. This is  useful  for  debugging,  but  also  illustrates  arguments  made
              available  to an access handler registered by the MagickSetConfirmAccessHandler() C
              library function.

       MAGICK_CODER_STABILITY
              The minimum coder stability level before it will be used. The available levels  are
              PRIMARY,  STABLE,  UNSTABLE,  and  BROKEN.   The default minimum level is UNSTABLE,
              which means that all available working coders will be used.  The  purpose  of  this
              option  is to reduce the security exposure (or apparent complexity) due to the huge
              number of formats supported. Coders at the PRIMARY level are commonly used  formats
              with  very  well  maintained  implementations.  Coders  at  the  STABLE  level  are
              reasonably well maintained but represent less used formats. Coders at the  UNSTABLE
              level  either  have  weak  implementations,  the file format itself is weak, or the
              probability the coder will be needed is vanishingly small.  Coders  at  the  BROKEN
              level  are known to often not work properly or might not be useful in their current
              state at all.

       MAGICK_CODER_MODULE_PATH
              Search path to use when searching for image format coder modules.  This path allows
              the  user  to  arbitrarily  extend the image formats supported by GraphicsMagick by
              adding loadable modules to an arbitrary location rather than copying them into  the
              GraphicsMagick installation directory. The formatting of the search path is similar
              to operating system search paths (i.e. colon delimited  for  Unix,  and  semi-colon
              delimited  for  Microsoft  Windows). This user specified search path is used before
              trying the default search path.

       MAGICK_CONFIGURE_PATH
              Search path to use when searching for configuration (.mgk) files.   The  formatting
              of  the  search  path  is  similar  to  operating  system  search paths (i.e. colon
              delimited for Unix, and semi-colon delimited  for  Microsoft  Windows).  This  user
              specified search path is used before trying the default search path.

       MAGICK_DEBUG
              Debug  options (see -debug for details).  Setting the configure debug option via an
              environment variable (e.g. MAGICK_DEBUG=configure) is necessary to see the complete
              initialization process, which includes searching for configuration files.

       MAGICK_FILTER_MODULE_PATH
              Search  path  to  use  when  searching  for  filter  process  modules  (invoked via
              -process). This path allows the user to arbitrarily extend  GraphicsMagick's  image
              processing functionality by adding loadable modules to an arbitrary location rather
              than copying them into the GraphicsMagick installation directory. The formatting of
              the  search  path is similar to operating system search paths (i.e. colon delimited
              for Unix, and semi-colon delimited for  Microsoft  Windows).  This  user  specified
              search path is used before trying the default search path.

       MAGICK_GHOSTSCRIPT_PATH
              For Microsoft Windows, specify the path to the Ghostscript installation rather than
              searching for it via the Windows registry.  This helps in case Ghostscript  is  not
              installed via the Ghostscript Windows installer or the user wants more control over
              the Ghostscript used.

       MAGICK_HOME
              Path  to  top  of  GraphicsMagick  installation   directory.   Only   observed   by
              "uninstalled"  builds of GraphicsMagick which do not have their location hard-coded
              or set by an installer.

       MAGICK_MMAP_READ
              If MAGICK_MMAP_READ is set to TRUE, GraphicsMagick will attempt to  memory-map  the
              input   file  for  reading.  This  usually  substantially  improves  repeated  read
              performance since the file is already in memory after the first time  it  has  been
              read. However, testing shows that performance may be reduced for files accessed for
              the first time since data is accessed via page-faults (upon first access) and  many
              operating  systems  fail  to  do  sequential read-ahead of memory mapped files, and
              particularly if those files are accessed over a network.  If many large input files
              are  read,  then  enabling  this  option  may  harm  performance by overloading the
              operating system's VM system as it then needs to free unmapped pages  and  map  new
              ones.

       MAGICK_IO_FSYNC
              If MAGICK_IO_FSYNC is set to TRUE, then GraphicsMagick will request that the output
              file is fully flushed and synchronized to disk when it is  closed.  This  incurs  a
              performance  penalty,  but  has  the  benefit that if the power fails or the system
              crashes, the file should be valid on disk. If image files  are  referenced  from  a
              database,  then  this option helps assure that the files referenced by the database
              are valid.

       MAGICK_IOBUF_SIZE
              The amount of I/O buffering (in bytes) to use  when  reading  and  writing  encoded
              files.  The  default  is  16384, which is observed to work well for many cases. The
              best value for a local filesystem is usually the the native filesystem  block  size
              (e.g.  4096,  8192,  or  even  131,072  for ZFS) in order to minimize the number of
              physical disk I/O operations.  I/O performance to files accessed over a network may
              benefit  significantly  by  tuning  this  option. Larger values are not necessarily
              better (they may be slower!), and there is rarely any  benefit  from  using  values
              larger  than  32768.  Use  convert's  -verbose option in order to evaluate read and
              write rates in pixels per second while keeping in mind that  the  operating  system
              will try to cache files in RAM.

       MAGICK_LIMIT_DISK
              Maximum amount of disk space allowed for use by the pixel cache.

       MAGICK_LIMIT_FILES
              Maximum number of open files.

       MAGICK_LIMIT_MAP
              Maximum  size  of  a  memory mapped file allocation.  A memory mapped file consumes
              memory when the file is accessed, although the system may reclaim such memory  when
              needed.

       MAGICK_LIMIT_MEMORY
              Maximum amount of memory to allocate from the heap.

       MAGICK_LIMIT_PIXELS
              Maximum  number  of  total  pixels (image rows times image colums) to allow for any
              image which is requested to be created or read.  This is useful to place a limit on
              how  large  an  image  may be.  If the input image file has image dimensions larger
              than the pixel limit, then the image memory allocation is denied and  an  error  is
              returned  immediately.   This  is  a  per-image  limit and does not limit the total
              number of pixels due to multiple image frames/pages (e.g. multi-page document or an
              animation).

       MAGICK_LIMIT_READ
              Maximum  number  of  uncompressed  bytes which may be read while decoding an image.
              Each read by the software from the input file is counted against the total, even if
              it  has  been  read  before.  Decoding fails when the limit is reached.  This limit
              helps defend against highly compressed files (e.g. via gzip), or  files  which  use
              complex looping structures, or when data is being read from a stream (pipe).

       MAGICK_LIMIT_WIDTH
              Maximum pixel width of an image read, or created.

       MAGICK_LIMIT_HEIGHT
              Maximum pixel height of an image read, or created.

       MAGICK_TMPDIR
              Path to directory where GraphicsMagick should write temporary files. The default is
              to use the system default, or the location set by TMPDIR.

       TMPDIR For POSIX-compatible systems (Unix-compatible), the path to the directory where all
              applications  should  write  temporary files.  Overridden by MAGICK_TMPDIR if it is
              set.

       TMP or TEMP
              For Microsoft Windows, the path to the directory where  applications  should  write
              temporary files. Overridden by MAGICK_TMPDIR if it is set.

       OMP_NUM_THREADS
              As per the OpenMP standard, this specifies the number of threads to use in parallel
              regions. Some compilers default the number of threads  to  use  to  the  number  of
              processor  cores  available while others default to just one thread. See the OpenMP
              specification for other standard adjustments and your compiler's manual for vendor-
              specific settings.

CONFIGURATION FILES

       GraphicsMagick uses a number of XML format configuration files:

       colors.mgk
              colors configuration file

                <?xml version="1.0"?>
                <colormap>
                  <color name="AliceBlue" red="240" green="248" blue="255"
                         compliance="SVG, X11, XPM" />
                </colormap>

       delegates.mgk
              delegates configuration file

       log.mgk
              logging configuration file

                <?xml version="1.0"?>
                <magicklog>
                  <log events="None" />
                  <log output="stdout" />
                  <log filename="Magick-%d.log" />
                  <log generations="3" />
                  <log limit="2000" />
                  <log format="%t %r %u %p %m/%f/%l/%d:\n  %e"  />
                </magicklog>

       modules.mgk
              loadable modules configuration file

                <?xml version="1.0"?>
                <modulemap>
                  <module magick="8BIM" name="META" />
                </modulemap>

       type.mgk
              master type (fonts) configuration file

                <?xml version="1.0"?>
                <typemap>
                  <include file="type-windows.mgk" />
                  <type
                    name="AvantGarde-Book"
                    fullname="AvantGarde Book"
                    family="AvantGarde"
                    foundry="URW"
                    weight="400"
                    style="normal"
                    stretch="normal"
                    format="type1"
                    metrics="/usr/local/share/ghostscript/fonts/a010013l.afm"
                    glyphs="/usr/local/share/ghostscript/fonts/a010013l.pfb"
                  />
                </typemap>

GM ANIMATE

       Animate  displays  a  sequence  of  images on any workstation display running an X server.
       animate first determines the hardware capabilities of the workstation. If  the  number  of
       unique colors in an image is less than or equal to the number the workstation can support,
       the image is displayed in an X window. Otherwise the number of  colors  in  the  image  is
       first reduced to match the color resolution of the workstation before it is displayed.

       This  means  that a continuous-tone 24 bits-per-pixel image can display on a 8 bit pseudo-
       color device or monochrome device. In most  instances  the  reduced  color  image  closely
       resembles  the  original.  Alternatively,  a monochrome or pseudo-color image sequence can
       display on a continuous-tone 24 bits-per-pixel device.

       To help prevent color flashing on X server visuals that have colormaps, animate creates  a
       single  colormap from the image sequence. This can be rather time consuming. You can speed
       this operation up by reducing the colors in the  image  before  you  "animate"  them.  Use
       mogrify  to  color  reduce  the  images  to a single colormap. See mogrify(1) for details.
       Alternatively, you can use a Standard Colormap; or a static, direct, or true color visual.
       You can define a Standard Colormap with xstdcmap. See xstdcmap(1) for details. This method
       is recommended for colormapped X server because it eliminates the need to compute a global
       colormap.

EXAMPLES

       To animate a set of images of a cockatoo, use:

           gm animate cockatoo.*

       To animate a cockatoo image sequence while using the Standard Colormap best, use:

           xstdcmap -best
           gm animate -map best cockatoo.*

       To animate an image of a cockatoo without a border centered on a backdrop, use:

           gm animate +borderwidth -backdrop cockatoo.*

OPTIONS

       For a more detailed description of each option, see Options, above.

       -authenticate <string>
              decrypt image with this password

       -backdrop
              display the image centered on a backdrop.

       -background <color>
              the background color

       -bordercolor <color>
              the border color

       -borderwidth <geometry>
              the border width

       -chop <width>x<height>{+-}<x>{+-}<y>{%}
              remove pixels from the interior of an image

       -colormap <type>
              define the colormap type

       -colors <value>
              preferred number of colors in the image

       -colorspace <value>
              the type of colorspace

       -crop <width>x<height>{+-}<x>{+-}<y>{%}
              preferred size and location of the cropped image

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -delay <1/100ths of a second>
              display the next image after pausing

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -display <host:display[.screen]>
              specifies the X server to contact

       -dispose <method>
              GIF disposal method

       -dither
              apply Floyd/Steinberg error diffusion to the image

       -font <name>
              use this font when annotating the image with text

       -foreground <color>
              define the foreground color

       -gamma <value>
              level of gamma correction

       -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
              Specify dimension, offset, and resize options.

       -help  print usage instructions

       -iconGeometry <geometry>
              specify the icon geometry

       -iconic
              iconic animation

       -interlace <type>
              the type of interlacing scheme

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -log <string>
              Specify format for debug log

       -map <type>
              display image using this type.

       -matte store matte channel if the image has one

       -mattecolor <color>
              specify the color to be used with the -frame option

       -monitor
              show progress indication

       -monochrome
              transform the image to black and white

       -name  name an image

       -noop  NOOP (no option)

       -pause <seconds>
              pause between animation loops [animate]

       -remote
              perform a X11 remote operation

       -rotate <degrees>{<}{>}
              rotate the image

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -scenes <value-value>
              range of image scene numbers to read

       -shared-memory
              use shared memory

       -size <width>x<height>{+offset}
              width and height of the image

       -text-font <name>
              font for writing fixed-width text

       -title <string>
              assign title to displayed image [animate, display, montage]

       -treedepth <value>
              tree depth for the color reduction algorithm

       -trim  trim an image

       -type <type>
              the image type

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

       -visual <type>
              animate images using this X visual type

       -window <id>
              make image the background of a window

              For a more detailed description of each option, see Options, above.

              Any  option  you  specify  on  the  command line remains in effect for the group of
              images following it, until the group is terminated by the appearance of any  option
              or  -noop.   For  example,  to  animate three images, the first with 32 colors, the
              second with an unlimited number of colors, and the third with only 16 colors, use:

                  gm animate -colors 32 cockatoo.1 -noop cockatoo.2
                           -colors 16 cockatoo.3

              Animate options can appear on the command line or in your  X  resources  file.  See
              X(1).  Options  on  the command line supersede values specified in your X resources
              file.  Image filenames may appear in any order on the command  line  if  the  image
              format  is  MIFF (refer to miff(5) and the scene keyword is specified in the image.
              Otherwise the images will display in the order they appear on the command line.

MOUSE BUTTONS

       Press any button to map or unmap the  Command  widget.  See  the  next  section  for  more
       information about the Command widget.

COMMAND WIDGET

       The Command widget lists a number of sub-menus and commands. They are

           Animate

               Open
               Play
               Step
               Repeat
               Auto Reverse

           Speed

               Faster
               Slower

           Direction

               Forward
               Reverse

           Image Info
           Help
           Quit

       Menu  items  with  a  indented triangle have a sub-menu. They are represented above as the
       indented items. To access a sub-menu item, move the pointer to the  appropriate  menu  and
       press  a  button and drag. When you find the desired sub-menu item, release the button and
       the command is executed.  Move the pointer away from the sub-menu if  you  decide  not  to
       execute a particular command.

KEYBOARD ACCELERATORS

               Ctl+O

                    Press to load an image from a file.
               space

                    Press to display the next image in the sequence.
               <

                    Press  to  speed-up  the  display  of  the  images.  Refer to -delay for more
                    information.
               >

                    Press to  slow  the  display  of  the  images.   Refer  to  -delay  for  more
                    information.
               ?

                    Press  to  display  information  about the image.  Press any key or button to
                    erase the information.
                    This information is printed: image name;  image size; and the total number of
                    unique colors in the image.
               F1

                    Press to display helpful information about animate(1).
               Ctl-q

                    Press to discard all images and exit program.

X RESOURCES

       Animate  options can appear on the command line or in your X resource file. Options on the
       command line supersede values specified in  your  X  resource  file.  See  X(1)  for  more
       information on X resources.

       All animate options have a corresponding X resource. In addition, the animate program uses
       the following X resources:

               background (class Background)

                    Specifies the preferred color to use for the  Image  window  background.  The
                    default is #ccc.
               borderColor (class BorderColor)

                    Specifies the preferred color to use for the Image window border. The default
                    is #ccc.
               borderWidth (class BorderWidth)

                    Specifies the width in pixels of the Image window border. The default is 2.
               font (class Font or FontList)

                    Specifies the name of the preferred font to use  in  normal  formatted  text.
                    The default is 14 point Helvetica.
               foreground (class Foreground)

                    Specifies  the  preferred color to use for text within the Image window.  The
                    default is black.
               geometry (class geometry)

                    Specifies the preferred size and position of the  image  window.  It  is  not
                    necessarily  obeyed by all window managers.  Offsets, if present, are handled
                    in X(1) style.  A negative x offset is measured from the right  edge  of  the
                    screen  to  the  right  edge of the icon, and a negative y offset is measured
                    from the bottom edge of the screen to the bottom edge of the icon.
               iconGeometry (class IconGeometry)

                    Specifies the preferred size and position of the application when  iconified.
                    It  is  not  necessarily obeyed by all window managers.  Offsets, if present,
                    are handled in the same manner as in class Geometry.
               iconic (class Iconic)

                    This resource indicates that you would prefer that the application's  windows
                    initially  not  be  visible as if the windows had be immediately iconified by
                    you. Window managers may choose not to honor the application's request.
               matteColor (class MatteColor)

                    Specify the color of windows. It is used  for  the  backgrounds  of  windows,
                    menus,  and  notices.  A  3D effect is achieved by using highlight and shadow
                    colors derived from this color. Default value: #ddd.
               name (class Name)

                    This resource specifies the name under which resources  for  the  application
                    should  be  found.  This  resource  is useful in shell aliases to distinguish
                    between invocations of an application, without resorting to creating links to
                    alter the executable file name. The default is the application name.
               sharedMemory (class SharedMemory)

                    This  resource specifies whether animate should attempt use shared memory for
                    pixmaps. ImageMagick must be compiled with shared  memory  support,  and  the
                    display  must  support  the  MIT-SHM  extension.  Otherwise, this resource is
                    ignored. The default is True.
               text_font (class textFont)

                    Specifies the name of the preferred font to use in fixed  (typewriter  style)
                    formatted text. The default is 14 point Courier.
               title (class Title)

                    This  resource  specifies  the  title  to  be used for the Image window. This
                    information is sometimes used by a window manager to  provide  some  sort  of
                    header identifying the window. The default is the image file name.

GM BATCH

DESCRIPTION

       batch  executes an arbitary number of the utility commands (e.g. convert) in the form of a
       simple linear batch script in order to improve execution efficiency, and/or to  allow  use
       as a subordinate co-process under the control of an arbitrary script or program.

EXAMPLES

        To drive 'gm batch' using a shell script (or a program written in any language), have the
       script/program send commands to 'gm batch' via its standard input.  Specify that  standard
       input  should  be  used by using '-' as the file name.  The following example converts all
       files matching '*.jpg' to TIFF format while rotating each file by 90 degrees and stripping
       all embedded profiles.  The shell script syntax is standard Unix shell:

         for file in *.jpg
         do
           outfile=`basename $file .jpg`.tiff
           echo convert -verbose "'$file'" -rotate 90 \
           +profile "'*'" "'$outfile'"
         done | gm batch -echo on -feedback on -

       We  can  accomplish the same as the previous example by putting all the commands in a text
       file and then specifying the name of the text file as the script to execute:

         for file in *.jpg
         do
           outfile=`basename $file .jpg`.tiff
           echo convert -verbose "'$file'" -rotate 90 \
           +profile "'*'" "'$outfile'"
         done > script.txt
         gm batch -echo on -feedback on script.txt

OPTIONS

       Options are processed from left to right and must appear before any filename argument.

       -echo on|off
              command echo on or off

              Specify on to enable echoing commands to standard output as they are read or off to
              disable.  The default is off.

       -escape unix|windows
              Parse using unix or windows syntax

              Commands  must  be  parsed  from  the input stream and escaping needs to be used to
              protect spaces or quoting characters in the input. Specify unix to  use  unix-style
              command  line parsing or windows for Microsoft Windows command shell style parsing.
              The default depends on if the software is compiled for Microsoft Windows or  for  a
              Unix-type system (including Cygwin on Microsoft Windows).  It is recommended to use
              unix syntax because it is more powerful and more portable.

       -fail text
              text to print if a command fails

              When feedback is enabled, this specifies the text to print when the command  fails.
              The default text is FAIL.

       -feedback on|off
              enable error feedback

              Print  text  (see  -pass and -fail options) feedback after each command to indicate
              the result, the default is off.

       -help

              Prints batch command help.

       -pass text
              text to print if a command passes

              When feedback is enabled, this specifies the text to print when the command passes.
              The default text is PASS.

       -prompt text
              Prompt text to use for command line

              If  no  filename  argument was specified, a simple command prompt appears where you
              may enter GraphicsMagick commands.  The default prompt is GM>.  Use this option  to
              change the prompt to something else.

       -stop-on-error on|off
              Specify if command processing stops on error

              Normally  command  processing  continues if a command encounters an error.  Specify
              -stop-on-error on to cause processing to quit immediately on error.

GM BENCHMARK

DESCRIPTION

       benchmark executes an arbitrary gm utility command (e.g. convert) for one or  more  loops,
       and/or  a  specified execution time, and reports many execution metrics.  For builds using
       OpenMP, a mode is provided to execute the benchmark with an increasing number  of  threads
       and  provide  a  report of speedup and multi-thread execution efficiency.  If benchmark is
       used to execute a command without any additional benchmark options, then  the  command  is
       run once.

EXAMPLES

       To obtain benchmark information for a single execution of a command:

           gm benchmark convert input.ppm -gaussian 0x1 output.ppm
       To obtain benchmark information from 100 iterations of the command:

           gm benchmark -iterations 100 convert input.ppm \
             -gaussian 0x1 output.ppm
       To  obtain benchmark information by iterating the command until a specified amount of time
       (in seconds) has been consumed:

           gm benchmark -duration 30 convert input.ppm \
             -gaussian 0x1 output.ppm
       To obtain a full performance report with an increasing number of  threads  (1-32  threads,
       stepping the number of threads by four each time):

           gm benchmark -duration 3 -stepthreads 4 convert \
             input.ppm -gaussian 0x2 output.ppm
       Here is the interpretation of the output:

           threads - number of threads used.
           iter - number of command iterations executed.
           user - total user time consumed.
           total - total elapsed time consumed.
           iter/s - number of command iterations per second.
           iter/cpu - amount of CPU time consumed per iteration.
           speedup - speedup compared with one thread.
           karp-flatt - Karp-Flatt measure of speedup efficiency.

       Please note that the reported "speedup" is based on the execution time of just one thread.
       A preliminary warm-up pass is used before timing the first loop in order  to  ensure  that
       the  CPU  is brought out of power-saving modes and that system caches are warmed up.  Most
       modern CPUs provide a "turbo" mode where the CPU clock  speed  is  increased  (e.g.  by  a
       factor  of  two)  when only one or two cores are active.  If the CPU grows excessively hot
       (due to insufficient cooling), then it may dial back its clock rates as a form of  thermal
       management.   These factors result in an under-reporting of speedup compared to if "turbo"
       mode was disabled and the CPU does not  need  to  worry  about  thermal  management.   The
       powertop  utility  available  under  Linux  and Solaris provides a way to observe CPU core
       clock rates while a benchmark is running.

OPTIONS

        Options are processed from left to right and must appear before any argument.

       -duration duration
              duration to run benchmark Specify the number of seconds to run the  benchmark.  The
              command is executed repeatedly until the specified amount of time has elapsed.

       -help

              Prints benchmark command help.

       -iterations loops
              number of command iterations Specify the number of iterations to run the benchmark.
              The command is executed repeatedly until the specified  number  of  iterations  has
              been reached.

       -rawcsv
              Print  results  in CSV format Print results in a comma-separated value (CSV) format
              which is easy to parse for plotting or importing into a  spreadsheet  or  database.
              The values reported are threads, iterations, user_time, and elapsed_time.

       -stepthreads step
              execute a per-thread benchmark ramp
               Execute  a  per-thread  benchmark ramp, incrementing the number of threads at each
              step by the specified value.  The maximum number  of  threads  is  taken  from  the
              standard OMP_NUM_THREADS environment variable.

GM COMPARE

       compare  compares  two  similar  images using a specified statistical method (see -metric)
       and/or by writing a difference image (-file), with the altered pixels  annotated  using  a
       specified  method (see -highlight-style) and color (see -highlight-color). Reference-image
       is the original image and compare-image is the (possibly) altered  version,  which  should
       have the same dimensions as reference-image.

EXAMPLES

       To compare two images using Mean Square Error (MSE) statistical analysis use:

           gm compare -metric mse original.miff compare.miff

       To create an annotated difference image use:

           gm compare -highlight-style assign -highlight-color purple \
             -file diff.miff original.miff compare.miff

OPTIONS

       Options  are  processed  in command line order. Any option you specify on the command line
       remains in effect only for the image that follows.  All options are reset to their default
       values after each image is read.

       For a more detailed description of each option, see Options, above.

       -authenticate <string>
              decrypt image with this password

       -auto-orient
              orient (rotate) image so it is upright

       -colorspace <value>
              the type of colorspace

       -compress <type>
              the type of image compression

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -display <host:display[.screen]>
              specifies the X server to contact

       -endian <type>
              specify endianness (MSB, LSB, or Native) of image

       -file <filename>
              write annotated difference image to file

       -help  print usage instructions

       -highlight-color <color>
              pixel annotation color

       -highlight-style <style>
              pixel annotation style

       -interlace <type>
              the type of interlacing scheme

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -log <string>
              Specify format for debug log

       -matte store matte channel if the image has one

       -maximum-error <limit>
              specifies the maximum amount of total image error

       -metric <metric>
              comparison metric (MAE, MSE, PAE, PSNR, RMSE)

       -monitor
              show progress indication

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -size <width>x<height>{+offset}
              width and height of the image

       -type <type>
              the image type

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

              For a more detailed description of each option, see Options, above.

GM COMPOSITE

       composite composites (combines) images to create new images.  base-image is the base image
       and change-image contains the changes.  ouput-image is the result, and  normally  has  the
       same dimensions as base-image.

       The  optional  mask-image can be used to provide opacity information for change-image when
       it has none or if you want a different mask.  A mask image is typically grayscale and  the
       same  size as base-image. If mask-image is not grayscale, it is converted to grayscale and
       the resulting intensities are used as opacity information.

EXAMPLES

       To composite an image of a cockatoo with a perch, use:

           gm composite cockatoo.miff perch.ras composite.miff

       To compute the difference between images in a series, use:

           gm composite -compose difference series.2 series.1
                     difference.miff

       To composite an image of a cockatoo with a perch starting at location (100,150), use:

           gm composite -geometry +100+150 cockatoo.miff
                     perch.ras composite.miff

       To tile a logo across your image of a cockatoo, use

           gm convert +shade 30x60 cockatoo.miff mask.miff
           gm composite -compose bumpmap -tile logo.png
                     cockatoo.miff mask.miff composite.miff

       To composite a red, green, and blue color plane into a single composite image, try

           gm composite -compose CopyGreen green.png red.png
                     red-green.png
           gm composite -compose CopyBlue blue.png red-green.png
                     gm composite.png

OPTIONS

       Options are processed in command line order. Any option you specify on  the  command  line
       remains in effect only for the image that follows.  All options are reset to their default
       values after each image is read.

       For a more detailed description of each option, see Options, above.

       -authenticate <string>
              decrypt image with this password

       -background <color>
              the background color

       -blue-primary <x>,<y>
              blue chromaticity primary point

       -colors <value>
              preferred number of colors in the image

       -colorspace <value>
              the type of colorspace

       -comment <string>
              annotate an image with a comment

       -compose <operator>
              the type of image composition

       -compress <type>
              the type of image compression

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -displace <horizontal scale>x<vertical scale>
              shift image pixels as defined by a displacement map

       -display <host:display[.screen]>
              specifies the X server to contact

       -dispose <method>
              GIF disposal method

       -dissolve <percent>
              dissolve an image into another by the given percent

       -dither
              apply Floyd/Steinberg error diffusion to the image

       -encoding <type>
              specify the text encoding

       -endian <type>
              specify endianness (MSB, LSB, or Native) of image

       -filter <type>
              use this type of filter when resizing an image

       -font <name>
              use this font when annotating the image with text

       -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
              Specify dimension, offset, and resize options.

       -gravity <type>
              direction primitive  gravitates to when annotating the image.

       -green-primary <x>,<y>
              green chromaticity primary point

       -help  print usage instructions

       -interlace <type>
              the type of interlacing scheme

       -label <name>
              assign a label to an image

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -log <string>
              Specify format for debug log

       -matte store matte channel if the image has one

       -monitor
              show progress indication

       -monochrome
              transform the image to black and white

       -negate
              replace every pixel with its complementary color

       -page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
              size and location of an image canvas

       -profile <filename>
              add ICM, IPTC, or generic profile  to image

       -quality <value>
              JPEG/MIFF/PNG/TIFF compression level

       -recolor <matrix>
              apply a color translation matrix to image channels

       -red-primary <x>,<y>
              red chromaticity primary point

       -render
              render vector operations

       -repage  <width>x<height>+xoff+yoff[!]
              Adjust image page offsets

       -resize <width>x<height>{%}{@}{!}{<}{>}
              resize an image

       -rotate <degrees>{<}{>}
              rotate the image

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -scene <value>
              set scene number

       -set <attribute> <value>
              set an image attribute

       +set <attribute>
              unset an image attribute

       -sharpen <radius>{x<sigma>}
              sharpen the image

       -size <width>x<height>{+offset}
              width and height of the image

       -stegano <offset>
              hide watermark within an image

       -stereo
              composite two images to create a stereo anaglyph

       -strip remove all profiles and text attributes from the image

       -thumbnail <width>x<height>{%}{@}{!}{<}{>}
              resize an image (quickly)

       -treedepth <value>
              tree depth for the color reduction algorithm

       -trim  trim an image

       -type <type>
              the image type

       -units <type>
              the units of image resolution

       -unsharp <radius>{x<sigma>}{+<amount>}{+<threshold>}
              sharpen the image with an unsharp mask operator

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

       -watermark <brightness>x<saturation>
              percent brightness and saturation of a watermark

       -white-point <x>,<y>
              chromaticity white point

       -write <filename>
              write an intermediate image [convert, composite]

              For a more detailed description of each option, see Options, above.

GM CONJURE

       The Magick scripting language (MSL) will primarily benefit those that want  to  accomplish
       custom image processing tasks but do not wish to program, or those that do not have access
       to a Perl interpreter or a compiler.  The interpreter is called conjure  and  here  is  an
       example script:

           <?xml version="1.0" encoding="UTF-8"?>
           <image size="400x400" >
             <read filename="image.gif" />
             <get width="base-width" height="base-height" />
             <resize geometry="%[dimensions]" />
             <get width="width" height="height" />
             <print output=
               "Image sized from %[base-width]x%[base-height]
                to %[width]x%[height].\n" />
             <write filename="image.png" />
           </image>

       invoked with

           gm conjure -dimensions 400x400 incantation.msl

       All  operations  will  closely  follow  the  key/value pairs defined in PerlMagick, unless
       otherwise noted.

OPTIONS

       Options are processed in command line order. Any option you specify on  the  command  line
       remains  in  effect  until  it is explicitly changed by specifying the option again with a
       different effect, or if it is changed by a statement in the scripting language.

       You can define your own keyword/value pairs on the command line.  The script can then  use
       this  information when setting values by including %[keyword] in the string.  For example,
       if you included "-dimensions 400x400" on the command line, as illustrated above, then  any
       string  containing "%[dimensions]" would have 400x400 substituted.  The "%[string]" can be
       used either an entire string, such as geometry="%[dimensions]" or as a part  of  a  string
       such as filename="%[basename].png".

       The  keyword  can  be  any string except for the following reserved strings (in any upper,
       lower, or mixed case variant): debug, help, and verbose, whose usage is described below.

       The value can be any string.  If either the keyword or the value contains white  space  or
       any symbols that have special meanings to your shell such as "#", "|", or "%", enclose the
       string in quotation marks or use "\" to escape the white space and special symbols.

       Keywords and values are case dependent.  "Key", "key", and "KEY" would be three  different
       keywords.

       For a more detailed description of each option, see Options, above.

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -help  print usage instructions

       -log <string>
              Specify format for debug log

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

MAGICK SCRIPTING LANGUAGE

       The  Magick  Scripting  Language  (MSL) presently defines the following elements and their
       attributes:

               <image>

                    background, color, id, size

                    Define a new image object.  </image> destroys it. Because  of  this,  if  you
                    wish  to  reference multiple "subimages" (aka pages or layers), you can embed
                    one image element inside of another. For example:

                        <image>
                        <read filename="input.png" />
                        <get width="base-width" height="base-height" />
                        <image height="base-height" width="base-width">
                        <image />
                        <write filename="output.mng" />
                        </image>

                        <image size="400x400" />

               <group>

                    Define a new group of image objects.  By default, images are only  valid  for
                    the life of their <image>element.

                        <image>   -- creates the image
                        .....     -- do stuff with it
                        </image>  -- dispose of the image

                    However,  in  a group, all images in that group will stay around for the life
                    of the group:

                        <group>                           -- start a group
                            <image>                       -- create an image
                            ....                          -- do stuff
                            </image>                      -- NOOP
                            <image>                       -- create another image
                            ....                          -- do more stuff
                            </image>                      -- NOOP
                            <write filename="image.mng" />  -- output
                        </group>                          -- dispose of both images

               <read>

                        filename

                    Read a new image from a disk file.

                        <read filename="image.gif" />

                    To read two images use

                        <read filename="image.gif" />
                        <read filename="image.png />

               <write>

                        filename
                    Write the image(s) to  disk,  either  as  a  single  multiple-image  file  or
                    multiple ones if necessary.

                         <write filename=image.tiff" />
               <get>

                    Get  any attribute recognized by PerlMagick's GetAttribute() and stores it as
                    an image attribute for  later  use.  Currently  only  width  and  height  are
                    supported.

                        <get width="base-width" height="base-height" />
                        <print output="Image size is %[base-width]x%[base-height].\n" />

               <set>

                    background,  bordercolor, clip-mask, colorspace, density, magick, mattecolor,
                    opacity.  Set an attribute recognized by PerlMagick's GetAttribute().
               <profile>

                        [profilename]

                    Read one or more IPTC, ICC or generic profiles from file and assign to image

                        <profile iptc="profile.iptc" generic="generic.dat" />

                    To remove a specified profile use "!" as the filename eg

                        <profile icm="!" iptc="profile.iptc" />

               <border>

                        fill, geometry, height, width
               <blur>

                        radius, sigma
               <charcoal>

                        radius, sigma
               <chop>

                        geometry, height, width, x, y
               <crop>

                        geometry, height, width, x, y
               <composite>

                        compose, geometry, gravity, image, x, y

                        <?xml version="1.0" encoding="UTF-8"?>
                        <group>
                            <image id="image_01">
                                <read filename="cloud3.gif"/>
                                <resize geometry="250x90"/>
                            </image>
                            <image id="image_02">
                                <read filename="cloud4.gif"/>
                                <resize geometry="190x100"/>
                            </image>
                            <image>
                                <read filename="background.jpg"/>
                                <composite image="image_01" geometry="+740+470"/>
                                <composite image="image_02" geometry="+390+415"/>
                            </image>
                            <write filename="result.png"/>
                        </group>

               <despeckle>

               <emboss>

                        radius, sigma
               <enhance>

               <equalize>

               <edge>

                        radius
               <flip>

               <flop>

               <frame>

                        fill, geometry, height, width, x, y, inner, outer
               <flatten>

               <get>

                        height, width
               <gamma>

                        red, green, blue
               <image>

                        background, color, id, size
               <implode>

                        amount
               <magnify>

               <minify>

               <medianfilter>

                        radius
               <normalize>

               <oilpaint>

                        radius
               <print>

                        output
               <profile>

                        [profilename]
               <read>

               <resize>

                        blur, filter, geometry, height, width
               <roll>

                        geometry, x, y
               <rotate>

                        degrees
               <reducenoise>

                        radius
               <sample>

                        geometry, height, width
               <scale>

                        geometry, height, width
               <sharpen>

                        radius, sigma
               <shave>

                        geometry, height, width
               <shear>

                        x, y
               <solarize>

                        threshold
               <spread>

                        radius
               <stegano>

                        image
               <stereo>

                        image
               <swirl>

                        degrees
               <texture>

                        image
               <threshold>

                        threshold
               <transparent>

                        color
               <trim>

GM CONVERT

       Convert converts an input file using one image format to an output file with  a  differing
       image  format.  In  addition,  various  types  of image processing can be performed on the
       converted image during the conversion process. Convert recognizes the image formats listed
       in GraphicsMagick(1).

EXAMPLES

       To make a thumbnail of a JPEG image, use:

           gm convert -size 120x120 cockatoo.jpg -resize 120x120
                   +profile "*" thumbnail.jpg

       In  this example, '-size 120x120' gives a hint to the JPEG decoder that the image is going
       to be downscaled to 120x120, allowing  it  to  run  faster  by  avoiding  returning  full-
       resolution  images  to GraphicsMagick for the subsequent resizing operation.  The ´-resize
       120x120' specifies the desired dimensions of the output image.  It will be scaled  so  its
       largest dimension is 120 pixels.  The ´+profile "*"' removes any ICM, EXIF, IPTC, or other
       profiles that might be present in the input and aren't needed in the thumbnail.

       To convert a MIFF image of a cockatoo to a SUN raster image, use:

           gm convert cockatoo.miff sun:cockatoo.ras

       To convert a multi-page PostScript document to individual FAX pages, use:

           gm convert -monochrome document.ps fax:page

       To convert a TIFF image to a PostScript A4 page with the  image  in  the  lower  left-hand
       corner, use:

           gm convert -page A4+0+0 image.tiff document.ps

       To convert a raw Gray image with a 128 byte header to a portable graymap, use:

           gm convert -depth 8 -size 768x512+128 gray:raw
                   image.pgm

       In  this example, "raw" is the input file.  Its format is "gray" and it has the dimensions
       and number of header bytes specified by the -size option and the sample depth specified by
       the  -depth  option.   The  output  file  is "image.pgm".  The suffix ".pgm" specifies its
       format.

       To convert a Photo CD image to a TIFF image, use:

           gm convert -size 1536x1024 img0009.pcd image.tiff
           gm convert img0009.pcd[4] image.tiff

       To create a visual image directory of all your JPEG images, use:

           gm convert 'vid:*.jpg' directory.miff

       To annotate an image with blue text using font 12x24 at position (100,100), use:

           gm convert -font helvetica -fill blue
                   -draw "text 100,100 Cockatoo"
                   bird.jpg bird.miff

       To tile a 640x480 image with a JPEG texture with bumps use:

           gm convert -size 640x480 tile:bumps.jpg tiled.png

       To surround an icon with an ornamental border to use with Mosaic(1), use:

           gm convert -mattecolor "#697B8F" -frame 6x6 bird.jpg
                   icon.png

       To create a MNG animation from a DNA molecule sequence, use:

           gm convert -delay 20 dna.* dna.mng

OPTIONS

       Options are processed in command line order. Any option you specify on  the  command  line
       remains  in  effect for the set of images that follows, until the set is terminated by the
       appearance of any option or -noop.  Some options only affect the decoding  of  images  and
       others only the encoding.  The latter can appear after the final group of input images.

       For a more detailed description of each option, see Options, above.

       -adjoin
              join images into a single multi-image file

       -affine <matrix>
              drawing transform matrix

       -antialias
              remove pixel aliasing

       -append
              append a set of images

       -asc-cdl <spec>
              apply ASC CDL color transform

       -authenticate <string>
              decrypt image with this password

       -auto-orient
              orient (rotate) image so it is upright

       -average
              average a set of images

       -background <color>
              the background color

       -black-threshold red[,green][,blue][,opacity]
              pixels below the threshold become black

       -blue-primary <x>,<y>
              blue chromaticity primary point

       -blur <radius>{x<sigma>}
              blur the image with a Gaussian operator

       -border <width>x<height>
              surround the image with a border of color

       -bordercolor <color>
              the border color

       -box <color>
              set the color of the annotation bounding box

       -channel <type>
              the type of channel

       -charcoal <factor>
              simulate a charcoal drawing

       -chop <width>x<height>{+-}<x>{+-}<y>{%}
              remove pixels from the interior of an image

       -clip  apply the clipping path, if one is present

       -coalesce
              merge a sequence of images

       -colorize <value>
              colorize the image with the pen color

       -colors <value>
              preferred number of colors in the image

       -colorspace <value>
              the type of colorspace

       -comment <string>
              annotate an image with a comment

       -compose <operator>
              the type of image composition

       -compress <type>
              the type of image compression

       -contrast
              enhance or reduce the image contrast

       -convolve <kernel>
              convolve image with the specified convolution kernel

       -crop <width>x<height>{+-}<x>{+-}<y>{%}
              preferred size and location of the cropped image

       -cycle <amount>
              displace image colormap by amount

       -debug <events>
              enable debug printout

       -deconstruct
              break down an image sequence into constituent parts

       -define <key>{=<value>},...
              add coder/decoder specific options

       -delay <1/100ths of a second>
              display the next image after pausing

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -despeckle
              reduce the speckles within an image

       -display <host:display[.screen]>
              specifies the X server to contact

       -dispose <method>
              GIF disposal method

       -dither
              apply Floyd/Steinberg error diffusion to the image

       -draw <string>
              annotate an image with one or more graphic primitives

       -edge <radius>
              detect edges within an image

       -emboss <radius>
              emboss an image

       -encoding <type>
              specify the text encoding

       -endian <type>
              specify endianness (MSB, LSB, or Native) of image

       -enhance
              apply a digital filter to enhance a noisy image

       -equalize
              perform histogram equalization to the image

       -extent <width>x<height>{+-}<x>{+-}<y>
              composite image on background color canvas image

       -fill <color>
              color to use when filling a graphic primitive

       -filter <type>
              use this type of filter when resizing an image

       -flatten
              flatten a sequence of images

       -flip  create a "mirror image"

       -flop  create a "mirror image"

       -font <name>
              use this font when annotating the image with text

       -format <string>
              output formatted image characteristics

       -frame <width>x<height>+<outer bevel width>+<inner bevel width>
              surround the image with an ornamental border

       -fuzz <distance>{%}
              colors within this Euclidean distance are considered equal

       -gamma <value>
              level of gamma correction

       -gaussian <radius>{x<sigma>}
              blur the image with a Gaussian operator

       -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
              Specify dimension, offset, and resize options.

       -gravity <type>
              direction primitive  gravitates to when annotating the image.

       -green-primary <x>,<y>
              green chromaticity primary point

       -hald-clut <clut>
              apply a Hald CLUT to the image

       -help  print usage instructions

       -implode <factor>
              implode image pixels about the center

       -intent <type>
              use this type of rendering intent when managing the image color

       -interlace <type>
              the type of interlacing scheme

       -label <name>
              assign a label to an image

       -lat <width>x<height>{+-}<offset>{%}
              perform local adaptive thresholding

       -level <black_point>{,<gamma>}{,<white_point>}{%}
              adjust the level of image contrast

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -list <type>
              the type of list

       -log <string>
              Specify format for debug log

       -loop <iterations>
              add Netscape loop extension to your GIF animation

       -magnify
              magnify the image

       -map <filename>
              choose a particular set of colors from this image

       -mask <filename>
              Specify a clipping mask

       -matte store matte channel if the image has one

       -mattecolor <color>
              specify the color to be used with the -frame option

       -median <radius>
              apply a median filter to the image

       -minify <factor>
              minify the image

       -modulate brightness[,saturation[,hue]]
              vary the brightness, saturation, and hue of an image

       -monitor
              show progress indication

       -monochrome
              transform the image to black and white

       -morph <frames>
              morphs an image sequence

       -mosaic
              create a mosaic from an image or an image sequence

       -motion-blur <radius>{x<sigma>}{+angle}
              Simulate motion blur

       -negate
              replace every pixel with its complementary color

       -noise <radius|type>
              add or reduce noise in an image

       -noop  NOOP (no option)

       -normalize
              transform image to span the full range of color values

       -opaque <color>
              change this color to the pen color within the image

       -operator channel operator rvalue[%]
              apply a mathematical, bitwise, or value operator to an image channel

       -ordered-dither <channeltype> <NxN>
              ordered dither the image

       -orient <orientation>
              Set the image orientation attribute

       -page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
              size and location of an image canvas

       -paint <radius>
              simulate an oil painting

       -pen <color>
              (This option has been replaced by the -fill option)

       -ping  efficiently determine image characteristics

       -pointsize <value>
              pointsize of the PostScript, X11, or TrueType font

       -preview <type>
              image preview type

       -process <command>
              process a sequence of images using a process module

       -profile <filename>
              add ICM, IPTC, or generic profile  to image

       -quality <value>
              JPEG/MIFF/PNG/TIFF compression level

       -raise <width>x<height>
              lighten or darken image edges

       -random-threshold <channeltype> <LOWxHIGH>
              random threshold the image

       -recolor <matrix>
              apply a color translation matrix to image channels

       -red-primary <x>,<y>
              red chromaticity primary point

       -region <width>x<height>{+-}<x>{+-}<y>
              apply options to a portion of the image

       -render
              render vector operations

       -repage  <width>x<height>+xoff+yoff[!]
              Adjust image page offsets

       -resample <horizontal>x<vertical>
              Resample image to specified horizontal and vertical resolution

       -resize <width>x<height>{%}{@}{!}{<}{>}
              resize an image

       -roll {+-}<x>{+-}<y>
              roll an image vertically or horizontally

       -rotate <degrees>{<}{>}
              rotate the image

       -sample <geometry>
              scale image using pixel sampling

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -scale <geometry>
              scale the image.

       -scene <value>
              set scene number

       -set <attribute> <value>
              set an image attribute

       +set <attribute>
              unset an image attribute

       -segment <cluster threshold>x<smoothing threshold>
              segment an image

       -shade <azimuth>x<elevation>
              shade the image using a distant light source

       -sharpen <radius>{x<sigma>}
              sharpen the image

       -shave <width>x<height>{%}
              shave pixels from the image edges

       -shear <x degrees>x<y degrees>
              shear the image along the X or Y axis

       -size <width>x<height>{+offset}
              width and height of the image

       -solarize <factor>
              negate all pixels above the threshold level

       -spread <amount>
              displace image pixels by a random amount

       -strip remove all profiles and text attributes from the image

       -stroke <color>
              color to use when stroking a graphic primitive

       -strokewidth <value>
              set the stroke width

       -swirl <degrees>
              swirl image pixels about the center

       -texture <filename>
              name of texture to tile onto the image background

       -threshold <value>{%}
              threshold the image

       -thumbnail <width>x<height>{%}{@}{!}{<}{>}
              resize an image (quickly)

       -tile <filename>
              tile image when filling a graphic primitive

       -transform
              transform the image

       -transparent <color>
              make this color transparent within the image

       -treedepth <value>
              tree depth for the color reduction algorithm

       -trim  trim an image

       -type <type>
              the image type

       -units <type>
              the units of image resolution

       -unsharp <radius>{x<sigma>}{+<amount>}{+<threshold>}
              sharpen the image with an unsharp mask operator

       -use-pixmap
              use the pixmap

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

       -view <string>
              FlashPix viewing parameters

       -virtual-pixel <method>
              specify contents of "virtual pixels"

       -wave <amplitude>x<wavelength>
              alter an image along a sine wave

       -white-point <x>,<y>
              chromaticity white point

       -white-threshold red[,green][,blue][,opacity]
              pixels above the threshold become white

       -write <filename>
              write an intermediate image [convert, composite]

              For a more detailed description of each option, see Options, above.

GM DISPLAY

       Display is a machine architecture independent image processing and display program. It can
       display an image on any workstation screen running an X server. Display can read and write
       many of the more popular image formats (e.g. JPEG, TIFF, PNM, Photo CD, etc.).

       With display, you can perform these functions on an image:

                o  load an image from a file
                o  display the next image
                o  display the former image
                o  display a sequence of images as a slide show
                o  write the image to a file
                o  print the image to a PostScript printer
                o  delete the image file
                o  create a Visual Image Directory
                o  select the image to display by its thumbnail rather than name
                o  undo last image transformation
                o  copy a region of the image
                o  paste a region to the image
                o  restore the image to its original size
                o  refresh the image
                o  half the image size
                o  double the image size
                o  resize the image
                o  crop the image
                o  cut the image
                o  flop image in the horizontal direction
                o  flip image in the vertical direction
                o  rotate the image 90 degrees clockwise
                o  rotate the image 90 degrees counter-clockwise
                o  rotate the image
                o  shear the image
                o  roll the image
                o  trim the image edges
                o  invert the colors of the image
                o  vary the color brightness
                o  vary the color saturation
                o  vary the image hue
                o  gamma correct the image
                o  sharpen the image contrast
                o  dull the image contrast
                o  perform histogram equalization on the image
                o  perform histogram normalization on the image
                o  negate the image colors
                o  convert the image to grayscale
                o  set the maximum number of unique colors in the image
                o  reduce the speckles within an image
                o  eliminate peak noise from an image
                o  detect edges within the image
                o  emboss an image
                o  segment the image by color
                o  simulate an oil painting
                o  simulate a charcoal drawing
                o  annotate the image with text
                o  draw on the image
                o  edit an image pixel color
                o  edit the image matte information
                o  composite an image with another
                o  add a border to the image
                o  surround image with an ornamental border
                o  apply image processing techniques to a region of interest
                o  display information about the image
                o  zoom a portion of the image
                o  show a histogram of the image
                o  display image to background of a window
                o  set user preferences
                o  display information about this program
                o  discard all images and exit program
                o  change the level of magnification
                o   display  images  specified by a World Wide Web (WWW) uniform resource locator
               (URL)

EXAMPLES

       To scale an image of a cockatoo to exactly 640 pixels in width and 480  pixels  in  height
       and position the window at location (200,200), use:

           gm display -geometry 640x480+200+200! cockatoo.miff

       To display an image of a cockatoo without a border centered on a backdrop, use:

           gm display +borderwidth -backdrop cockatoo.miff

       To tile a slate texture onto the root window, use:

           gm display -size 1280x1024 -window root slate.png

       To display a visual image directory of all your JPEG images, use:

           gm display 'vid:*.jpg'

       To  display  a  MAP  image  that  is 640 pixels in width and 480 pixels in height with 256
       colors, use:

           gm display -size 640x480+256 cockatoo.map

       To display an image of a cockatoo specified with a World Wide Web (WWW)  uniform  resource
       locator (URL), use:

           gm display ftp://wizards.dupont.com/images/cockatoo.jpg

       To display histogram of an image, use:

           gm gm convert file.jpg HISTOGRAM:- | gm display -

OPTIONS

       Options  are  processed  in command line order. Any option you specify on the command line
       remains in effect until it is explicitly changed by specifying the  option  again  with  a
       different  effect.  For  example  to  display  three images, the first with 32 colors, the
       second with an unlimited number of colors, and the third with only 16 colors, use:

           gm display -colors 32 cockatoo.miff -noop duck.miff
                        -colors 16 macaw.miff

       Display options can appear on the command line or in your  X  resources  file.  See  X(1).
       Options on the command line supersede values specified in your X resources file.

       For a more detailed description of each option, see Options, above.

       -authenticate <string>
              decrypt image with this password

       -backdrop
              display the image centered on a backdrop.

       -background <color>
              the background color

       -border <width>x<height>
              surround the image with a border of color

       -bordercolor <color>
              the border color

       -borderwidth <geometry>
              the border width

       -colormap <type>
              define the colormap type

       -colors <value>
              preferred number of colors in the image

       -colorspace <value>
              the type of colorspace

       -comment <string>
              annotate an image with a comment

       -compress <type>
              the type of image compression

       -contrast
              enhance or reduce the image contrast

       -crop <width>x<height>{+-}<x>{+-}<y>{%}
              preferred size and location of the cropped image

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -delay <1/100ths of a second>
              display the next image after pausing

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -despeckle
              reduce the speckles within an image

       -display <host:display[.screen]>
              specifies the X server to contact

       -dispose <method>
              GIF disposal method

       -dither
              apply Floyd/Steinberg error diffusion to the image

       -edge <radius>
              detect edges within an image

       -endian <type>
              specify endianness (MSB, LSB, or Native) of image

       -enhance
              apply a digital filter to enhance a noisy image

       -filter <type>
              use this type of filter when resizing an image

       -flip  create a "mirror image"

       -flop  create a "mirror image"

       -font <name>
              use this font when annotating the image with text

       -foreground <color>
              define the foreground color

       -frame <width>x<height>+<outer bevel width>+<inner bevel width>
              surround the image with an ornamental border

       -gamma <value>
              level of gamma correction

       -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
              Specify dimension, offset, and resize options.

       -help  print usage instructions

       -iconGeometry <geometry>
              specify the icon geometry

       -iconic
              iconic animation

       -immutable
              make image immutable

       -interlace <type>
              the type of interlacing scheme

       -label <name>
              assign a label to an image

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -log <string>
              Specify format for debug log

       -magnify <factor>
              magnify the image

       -map <type>
              display image using this type.

       -matte store matte channel if the image has one

       -mattecolor <color>
              specify the color to be used with the -frame option

       -monitor
              show progress indication

       -monochrome
              transform the image to black and white

       -name  name an image

       -negate
              replace every pixel with its complementary color

       -noop  NOOP (no option)

       -page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
              size and location of an image canvas

       +progress
              disable progress monitor and busy cursor

       -quality <value>
              JPEG/MIFF/PNG/TIFF compression level

       -raise <width>x<height>
              lighten or darken image edges

       -remote
              perform a X11 remote operation

       -roll {+-}<x>{+-}<y>
              roll an image vertically or horizontally

       -rotate <degrees>{<}{>}
              rotate the image

       -sample <geometry>
              scale image using pixel sampling

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -scenes <value-value>
              range of image scene numbers to read

       -set <attribute> <value>
              set an image attribute

       +set <attribute>
              unset an image attribute

       -segment <cluster threshold>x<smoothing threshold>
              segment an image

       -shared-memory
              use shared memory

       -sharpen <radius>{x<sigma>}
              sharpen the image

       -size <width>x<height>{+offset}
              width and height of the image

       -text-font <name>
              font for writing fixed-width text

       -texture <filename>
              name of texture to tile onto the image background

       -title <string>
              assign title to displayed image [animate, display, montage]

       -treedepth <value>
              tree depth for the color reduction algorithm

       -trim  trim an image

       -type <type>
              the image type

       -update <seconds>
               detect when image file is modified and redisplay.

       -use-pixmap
              use the pixmap

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

       -visual <type>
              animate images using this X visual type

       -window <id>
              make image the background of a window

       -window-group
              specify the window group

       -write <filename>
              write the image to a file [display]

              For a more detailed description of each option, see Options, above.

MOUSE BUTTONS

       The  effects  of  each button press is described below. Three buttons are required. If you
       have a two button mouse, button 1 and 3 are returned.  Press ALT and button 3 to  simulate
       button 2.

       1        Press  this  button to map or unmap the Command widget . See the next section for
              more information about the Command widget.

       2       Press and drag to define a region of the image to magnify.

       3       Press and drag to choose from a select set of  display(1)  commands.  This  button
              behaves  differently  if  the  image  being  displayed is a visual image directory.
              Choose a particular tile of the directory and press this button and drag to  select
              a command from a pop-up menu.  Choose from these menu items:

                  Open
                  Next
                  Former
                  Delete
                  Update

              If  you  choose Open, the image represented by the tile is displayed.  To return to
              the visual image directory, choose Next from the Command widget (refer  to  Command
              Widget).   Next  and  Former moves to the next or former image respectively. Choose
              Delete to delete a particular image tile. Finally, choose Update to synchronize all
              the  image  tiles  with  their  respective  images.  See  montage and miff for more
              details.

COMMAND WIDGET

       The Command widget lists a number of sub-menus and commands. They are

           File

           Open...
           Next
           Former
           Select...
           Save...
           Print...
           Delete...
           Canvas...
           Visual Directory...
           Quit

           Edit

           Undo
           Redo
           Cut
           Copy
           Paste

           View

           Half Size
           Original Size
           Double Size
           Resize...
           Apply
           Refresh
           Restore

           Transform

           Crop
           Chop
           Flop
           Flip
           Rotate Right
           Rotate Left
           Rotate...
           Shear...
           Roll...
           Trim Edges

           Enhance

           Hue...
           Saturation...
           Brightness...
           Gamma...
           Spiff...
           Dull
           Equalize
           Normalize
           Negate
           GRAYscale
           Quantize...

           Effects

           Despeckle
           Emboss
           Reduce Noise
           Add Noise
           Sharpen...
           Blur...
           Threshold...
           Edge Detect...
           Spread...
           Shade...
           Raise...
           Segment...

           F/X

           Solarize...
           Swirl...
           Implode...
           Wave...
           Oil Paint...
           Charcoal Draw...

           Image Edit

           Annotate...
           Draw...
           Color...
           Matte...
           Composite...
           Add Border...
           Add Frame...
           Comment...
           Launch...
           Region of Interest...

           Miscellany

           Image Info
           Zoom Image
           Show Preview...
           Show Histogram
           Show Matte
           Background...
           Slide Show
           Preferences...

           Help

           Overview
           Browse Documentation
           About Display

       Menu items with a indented triangle have a sub-menu. They are  represented  above  as  the
       indented  items.  To  access a sub-menu item, move the pointer to the appropriate menu and
       press button 1 and drag. When you find the desired sub-menu item, release the  button  and
       the  command  is  executed.   Move the pointer away from the sub-menu if you decide not to
       execute a particular command.

KEYBOARD ACCELERATORS

       Accelerators are one or two key presses that effect a particular  command.   The  keyboard
       accelerators that display understands is:

           Ctl+O     Press to load an image from a file.
           space     Press to display the next image.

       If  the  image is a multi-paged document such as a PostScript document, you can skip ahead
       several pages by preceding this command with a number.  For example to display the  fourth
       page beyond the current page, press 4space.

           backspace Press to display the former image.

       If  the image is a multi-paged document such as a PostScript document, you can skip behind
       several pages by preceding this command with a number.  For example to display the  fourth
       page preceding the current page, press 4n.

           Ctl-S    Press to save the image to a file.
           Ctl-P    Press to print the image to a
                    PostScript printer.
           Ctl-D    Press to delete an image file.
           Ctl-N    Press to create a blank canvas.
           Ctl-Q    Press to discard all images and exit program.
           Ctl+Z    Press to undo last image transformation.
           Ctl+R    Press to redo last image transformation.
           Ctl-X    Press to cut a region of
                    the image.
           Ctl-C    Press to copy a region of
                    the image.
           Ctl-V    Press to paste a region to
                    the image.
           <        Press to halve the image size.
           .        Press to return to the original image size.
           >        Press to double the image size.
           %        Press to resize the image to a width and height
                    you specify.
           Cmd-A    Press to make any image transformations
                    permanent.
                    By default, any image size transformations are
                    applied to the original image to create the
                    image displayed on the X server.  However, the
                    transformations are not permanent (i.e. the
                    original image does not change size only the
                    X image does). For example, if you press ">"
                    the X image will appear to double in size, but
                    the original image will in fact remain the same
                    size.  To force the original image to double in
                    size, press ">" followed by "Cmd-A".
           @        Press to refresh the image window.
           C        Press to crop the image.
           [        Press to chop the image.
           H        Press to flop image in the horizontal direction.
           V        Press to flip image in the vertical direction.
           /        Press to rotate the image 90 degrees clockwise.
           \        Press to rotate the image 90 degrees
                    counter-clockwise.
           *        Press to rotate the image
                    the number of degrees you specify.
           S        Press to shear the image the number of degrees
                    you specify.
           R        Press to roll the image.
           T        Press to trim the image edges.
           Shft-H   Press to vary the color hue.
           Shft-S   Press to vary the color saturation.
           Shft-L   Press to vary the image brightness.
           Shft-G   Press to gamma correct the image.
           Shft-C   Press to spiff up the image contrast.
           Shft-Z   Press to dull the image contrast.
           =        Press to perform histogram equalization on
                    the image.
           Shft-N   Press to perform histogram normalization on
                    the image.
           Shft-~   Press to negate the colors of the image.
           .        Press to convert the image colors to gray.
           Shft-#   Press to set the maximum number of unique
                    colors in the image.
           F2       Press to reduce the speckles in an image.
           F2       Press to emboss an image.
           F4       Press to eliminate peak noise from an image.
           F5       Press to add noise to an image.
           F6       Press to sharpen an image.
           F7       Press to blur image an image.
           F8       Press to threshold the image.
           F9       Press to detect edges within an image.
           F10      Press to displace pixels by a random amount.
           F11      Press to shade the image using a distant light
                    source.
           F12      Press to lighten or darken image edges to
                    create a 3-D effect.
           F13      Press to segment the image by color.
           Meta-S   Press to swirl image pixels about the center.
           Meta-I   Press to implode image pixels about the center.
           Meta-W   Press to alter an image along a sine wave.
           Meta-P   Press to simulate an oil painting.
           Meta-C   Press to simulate a charcoal drawing.
           Alt-X    Press to composite the image
                    with another.
           Alt-A    Press to annotate the image with text.
           Alt-D    Press to draw a line on the image.
           Alt-P    Press to edit an image pixel color.
           Alt-M    Press to edit the image matte information.
           Alt-X    Press to composite the image with another.
           Alt-A    Press to add a border to the image.
           Alt-F    Press to add a ornamental frame to the image.
           Alt-Shft-!   Press to add an image comment.
           Ctl-A    Press to apply image processing techniques to a
                    region of interest.
           Shft-?   Press to display information about the image.
           Shft-+   Press to map the zoom image window.
           Shft-P   Press to preview an image enhancement, effect,
                    or f/x.
           F1       Press to display helpful information about
                    the "display" utility.
           Find     Press to browse documentation about
                    GraphicsMagick.
           1-9      Press to change the level of magnification.

       Use the arrow keys to move the image one pixel up, down, left, or right within the magnify
       window. Be sure to first map the magnify window by pressing button 2.

       Press ALT and one of the arrow keys to trim off one pixel from any side of the image.

X RESOURCES

       Display options can appear on the command line or in your X resource file. Options on  the
       command  line  supersede  values  specified  in  your  X  resource file. See X(1) for more
       information on X resources.

       Most display options have a corresponding  X  resource.  In  addition,  display  uses  the
       following X resources:

       background (class Background)
                Specifies the preferred color to use for the Image window background. The default
              is #ccc.

       borderColor (class BorderColor)
               Specifies the preferred color to use for the Image window border. The  default  is
              #ccc.

       borderWidth (class BorderWidth)
               Specifies the width in pixels of the image window border. The default is 2.

       browseCommand (class browseCommand)
                Specifies  the  name  of  the  preferred  browser  when displaying GraphicsMagick
              documentation. The default is netscape %s.

       confirmExit (class ConfirmExit)
               Display pops up a dialog box to confirm  exiting  the  program  when  exiting  the
              program. Set this resource to False to exit without a confirmation.

       displayGamma (class DisplayGamma)
                Specifies  the gamma of the X server.  You can apply separate gamma values to the
              red, green, and blue channels of the image with a gamma value list delineated  with
              slashes (i.e. 1.7/2.3/1.2).  The default is 2.2.

       displayWarnings (class DisplayWarnings)
               Display pops up a dialog box whenever a warning message occurs.  Set this resource
              to False to ignore warning messages.

       font (class FontList)
               Specifies the name of the preferred font to use in  normal  formatted  text.   The
              default is 14 point Helvetica.

       font[1-9] (class Font[1-9])
                Specifies  the name of the preferred font to use when annotating the image window
              with text. The default fonts are fixed, variable, 5x8,  6x10,  7x13bold,  8x13bold,
              9x15bold, 10x20, and 12x24.

       foreground (class Foreground)
                Specifies  the  preferred  color  to  use  for text within the image window.  The
              default is black.

       gammaCorrect (class gammaCorrect)
               This resource, if true, will lighten or darken an image of known  gamma  to  match
              the gamma of the display (see resource displayGamma). The default is True.

       geometry (class Geometry)
                Specifies  the  preferred  size  and  position  of  the  image  window. It is not
              necessarily obeyed by all window managers.

              Offsets, if present, are handled in X(1) style.  A negative x  offset  is  measured
              from  the  right edge of the screen to the right edge of the icon, and a negative y
              offset is measured from the bottom edge of the screen to the  bottom  edge  of  the
              icon.

       iconGeometry (class IconGeometry)
                Specifies  the preferred size and position of the application when iconified.  It
              is not necessarily obeyed by all window managers.

              Offsets, if present, are handled in the same manner as in class Geometry.

       iconic (class Iconic)
               This resource indicates that you  would  prefer  that  the  application's  windows
              initially  not  be  visible  as if the windows had be immediately iconified by you.
              Window managers may choose not to honor the application's request.

       magnify (class Magnify)
               specifies an integral factor by which the image should be enlarged. The default is
              3.   This  value only affects the magnification window which is invoked with button
              number 3 after the image is displayed.

       matteColor (class MatteColor)
               Specify the color of windows. It is used for the backgrounds  of  windows,  menus,
              and  notices.  A 3D effect is achieved by using highlight and shadow colors derived
              from this color. Default value: #697B8F.

       name (class Name)
               This resource specifies the name under which resources for the application  should
              be  found.  This  resource  is  useful  in  shell  aliases  to  distinguish between
              invocations of an application, without resorting to creating  links  to  alter  the
              executable file name. The default is the application name.

       pen[1-9] (class Pen[1-9])
                Specifies the color of the preferred font to use when annotating the image window
              with text. The default colors are black, blue, green,  cyan,  gray,  red,  magenta,
              yellow, and white.

       printCommand (class PrintCommand)
                This command is executed whenever Print is issued.  In general, it is the command
              to print PostScript to your printer. Default value: lp -c -s %i.

       sharedMemory (class SharedMemory)
               This resource specifies whether display  should  attempt  use  shared  memory  for
              pixmaps.  GraphicsMagick  must  be  compiled  with  shared  memory support, and the
              display must support the MIT-SHM extension. Otherwise, this  resource  is  ignored.
              The default is True.

       textFont (class textFont)
                Specifies  the  name  of  the  preferred  font to use in fixed (typewriter style)
              formatted text. The default is 14 point Courier.

       title (class Title)
               This resource  specifies  the  title  to  be  used  for  the  image  window.  This
              information  is  sometimes used by a window manager to provide a header identifying
              the window. The default is the image file name.

       undoCache (class UndoCache)
               Specifies, in mega-bytes, the amount of memory in the undo edit cache.  Each  time
              you  modify  the  image  it  is  saved  in the undo edit cache as long as memory is
              available. You can subsequently undo one or  more  of  these  transformations.  The
              default is 16 Megabytes.

       usePixmap (class UsePixmap)
               Images are maintained as a XImage by default. Set this resource to True to utilize
              a server Pixmap instead. This option is useful if your image exceeds the dimensions
              of  your server screen and you intend to pan the image. Panning is much faster with
              Pixmaps than with a XImage. Pixmaps are considered a precious  resource,  use  them
              with discretion.

              To  set  the  geometry  of the Magnify or Pan or window, use the geometry resource.
              For example, to set the Pan window geometry to 256x256, use:

                  gm display.pan.geometry: 256x256

IMAGE LOADING

       To select an image to display, choose Open of the File sub-menu from the Command widget. A
       file  browser  is  displayed.   To choose a particular image file, move the pointer to the
       filename and press any button. The filename is copied to the text window. Next, press Open
       or press the RETURN key. Alternatively, you can type the image file name directly into the
       text window. To descend directories, choose a directory name and press  the  button  twice
       quickly. A scrollbar allows a large list of filenames to be moved through the viewing area
       if it exceeds the size of the list area.

       You can trim the list of file names by using shell globbing characters.  For example, type
       *.jpg to list only files that end with .jpg.

       To  select  your image from the X server screen instead of from a file, Choose Grab of the
       Open widget.

VISUAL IMAGE DIRECTORY

       To create a Visual Image Directory, choose Visual Directory of the File sub-menu from  the
       Command  widget . A file browser is displayed. To create a Visual Image Directory from all
       the  images  in  the  current  directory,  press  Directory  or  press  the  RETURN   key.
       Alternatively, you can select a set of image names by using shell globbing characters. For
       example, type *.jpg to include only files that end  with  .jpg.  To  descend  directories,
       choose  a  directory  name  and press the button twice quickly. A scrollbar allows a large
       list of filenames to be moved through the viewing area if it exceeds the size of the  list
       area.

       After  you  select a set of files, they are turned into thumbnails and tiled onto a single
       image. Now move the pointer to a  particular  thumbnail  and  press  button  3  and  drag.
       Finally,  select  Open.  The  image  represented by the thumbnail is displayed at its full
       size. Choose Next from the File sub-menu of the Command widget to  return  to  the  Visual
       Image Directory.

IMAGE CUTTING

       Note  that  cut  information  for  image  window  is not retained for colormapped X server
       visuals (e.g. StaticColor, StaticColor, GRAYScale, PseudoColor).  Correct cutting behavior
       may require a TrueColor or DirectColor visual or a Standard Colormap.

       To  begin,  press  choose Cut of the Edit sub-menu from the Command widget. Alternatively,
       press F3 in the image window.

       A small window appears showing the location of the cursor in the image window. You are now
       in cut mode. In cut mode, the Command widget has these options:

           Help
           Dismiss

       To  define  a  cut  region,  press  button  1  and  drag.  The  cut region is defined by a
       highlighted rectangle that expands or contracts as it follows the pointer.  Once  you  are
       satisfied  with  the  cut  region,  release  the  button.  You are now in rectify mode. In
       rectify mode, the Command widget has these options:

           Cut
           Help
           Dismiss

       You can make adjustments by moving the pointer  to  one  of  the  cut  rectangle  corners,
       pressing  a  button,  and dragging. Finally, press Cut to commit your copy region. To exit
       without cutting the image, press Dismiss.

IMAGE COPYING

       To begin, press choose Copy of the Edit sub-menu from the Command  widget.  Alternatively,
       press F4 in the image window.

       A small window appears showing the location of the cursor in the image window. You are now
       in copy mode. In copy mode, the Command widget has these options:

           Help
           Dismiss

       To define a copy region, press button 1  and  drag.  The  copy  region  is  defined  by  a
       highlighted  rectangle  that  expands or contracts as it follows the pointer. Once you are
       satisfied with the copy region, release the button.  You  are  now  in  rectify  mode.  In
       rectify mode, the Command widget has these options:

           Copy
           Help
           Dismiss

       You  can  make  adjustments  by  moving  the pointer to one of the copy rectangle corners,
       pressing a button, and dragging. Finally, press Copy to commit your copy region.  To  exit
       without copying the image, press Dismiss.

IMAGE PASTING

       To  begin, press choose Paste of the Edit sub-menu from the Command widget. Alternatively,
       press F5 in the image window.

       A small window appears showing the location of the cursor in the image window. You are now
       in  Paste mode. To exit immediately, press Dismiss.  In Paste mode, the Command widget has
       these options:

           Operators

           over
           in
           out
           atop
           xor
           plus
           minus
           add
           subtract
           difference
           multiply
           bumpmap
           replace

           Help
           Dismiss

       Choose a composite operation from the Operators sub-menu of the Command widget.  How  each
       operator behaves is described below. image window is the image currently displayed on your
       X server and image is the image obtained with the File Browser widget.

       over    The result is the union of the two image shapes, with image obscuring image window
              in the region of overlap.

       in       The  result  is simply image cut by the shape of image window.  None of the image
              data of image window is in the result.

       out     The resulting image is image with the shape of image window cut out.

       atop    The result is the same shape as image window, with image  obscuring  image  window
              where  the image shapes overlap. Note this differs from over because the portion of
              image outside image window's shape does not appear in the result.

       xor     The result is the image data from both image and image window that is outside  the
              overlap region. The overlap region is blank.

       plus     The  result  is  just the sum of the image data. Output values are cropped to the
              maximum value (no overflow). This operation is independent of the matte channels.

       minus   The result of image - image window, with underflow  cropped  to  zero.  The  matte
              channel is ignored (set to opaque, full coverage).

       add     The result of image + image window, with overflow wrapping around (mod MaxRGB+1).

       subtract
               The result of image - image window, with underflow wrapping around (mod MaxRGB+1).
              The add and subtract operators can be used to perform reversible transformations.

       difference
               The result of abs(image - image window). This is useful  for  comparing  two  very
              similar images.

       multiply
                The  result  of  image  *  image window. This is useful for the creation of drop-
              shadows.

       bumpmap
               The result of image window shaded by window.

       replace
              The  resulting  image  is  image  window  replaced  with  image.   Here  the  matte
              information is ignored.

              The  image  compositor  requires  a  matte,  or alpha channel in the image for some
              operations. This extra channel usually defines a mask which represents a sort of  a
              cookie-cutter for the image. This is the case when matte is 255 (full coverage) for
              pixels inside the shape, zero outside, and between zero and 255 on the boundary. If
              image  does  not  have  a  matte  channel,  it  is initialized with 0 for any pixel
              matching in color to pixel location (0,0), otherwise 255. See Matte Editing  for  a
              method of defining a matte channel.

              Note  that  matte  information  for  image window is not retained for colormapped X
              server visuals (e.g. StaticColor, StaticColor,  GrayScale,  PseudoColor).   Correct
              compositing  behavior  may  require a TrueColor or DirectColor visual or a Standard
              Colormap.

              Choosing a composite  operator  is  optional.  The  default  operator  is  replace.
              However,  you  must  choose  a location to composite your image and press button 1.
              Press and hold the button before releasing and an outline of the image will  appear
              to help you identify your location.

              The  actual colors of the pasted image is saved. However, the color that appears in
              image window may be different. For example, on a  monochrome  screen  image  window
              will  appear  black or white even though your pasted image may have many colors. If
              the image is saved to a file it is written with the correct colors. To  assure  the
              correct  colors  are saved in the final image, any PseudoClass image is promoted to
              DirectClass.  To force a PseudoClass image to remain PseudoClass, use -colors.

IMAGE CROPPING

       To  begin,  press  choose  Crop  of  the  Transform  submenu  from  the  Command   widget.
       Alternatively, press C in the image window.

       A small window appears showing the location of the cursor in the image window. You are now
       in crop mode. In crop mode, the Command widget has these options:

           Help
           Dismiss

       To define a cropping region, press button 1 and drag. The cropping region is defined by  a
       highlighted  rectangle  that  expands or contracts as it follows the pointer. Once you are
       satisfied with the cropping region, release the button. You are now in  rectify  mode.  In
       rectify mode, the Command widget has these options:

           Crop
           Help
           Dismiss

       You  can  make adjustments by moving the pointer to one of the cropping rectangle corners,
       pressing a button, and dragging. Finally, press Crop to commit your  cropping  region.  To
       exit without cropping the image, press Dismiss.

IMAGE CHOPPING

       An  image is chopped interactively. There is no command line argument to chop an image. To
       begin, choose Chop of the Transform sub-menu from the Command widget. Alternatively, press
       [ in the Image window.

       You  are  now in Chop mode. To exit immediately, press Dismiss.  In Chop mode, the Command
       widget has these options:

           Direction

           horizontal
           vertical

           Help
           Dismiss

       If the you choose the horizontal direction (this is the default), the area  of  the  image
       between  the two horizontal endpoints of the chop line is removed.  Otherwise, the area of
       the image between the two vertical endpoints of the chop line is removed.

       Select a location within the image window to begin your chop, press and hold  any  button.
       Next,  move the pointer to another location in the image.  As you move a line will connect
       the initial location and the pointer. When you release the button,  the  area  within  the
       image to chop is determined by which direction you choose from the Command widget.

       To  cancel the image chopping, move the pointer back to the starting point of the line and
       release the button.

IMAGE ROTATION

       Press the / key to  rotate  the  image  90  degrees  or  \  to  rotate  -90  degrees.   To
       interactively  choose  the  degree of rotation, choose Rotate...  of the Transform submenu
       from the Command Widget.  Alternatively, press * in the image window.

       A small horizontal line is drawn next to the pointer. You are now in rotate mode. To  exit
       immediately, press Dismiss. In rotate mode, the Command widget has these options:

           Pixel Color

           black
           blue
           cyan
           green
           gray
           red
           magenta
           yellow
           white
           Browser...

           Direction

           horizontal
           vertical

           Help
           Dismiss

       Choose  a background color from the Pixel Color sub-menu. Additional background colors can
       be specified with the color browser. You can change the  menu  colors  by  setting  the  X
       resources pen1 through pen9.

       If  you  choose  the  color browser and press Grab, you can select the background color by
       moving the pointer to the desired color on the screen and press any button.

       Choose a point in the image window and press this button and hold. Next, move the  pointer
       to another location in the image. As you move a line connects the initial location and the
       pointer. When you release the button, the degree of image rotation is  determined  by  the
       slope  of  the  line you just drew. The slope is relative to the direction you choose from
       the Direction sub-menu of the Command widget.

       To cancel the image rotation, move the pointer back to the starting point of the line  and
       release the button.

IMAGE ANNOTATION

       An  image  is  annotated  interactively.  There is no command line argument to annotate an
       image. To begin, choose Annotate of the Image  Edit  sub-menu  from  the  Command  widget.
       Alternatively, press a in the image window.

       A small window appears showing the location of the cursor in the image window. You are now
       in annotate mode. To exit immediately, press  Dismiss.   In  annotate  mode,  the  Command
       widget has these options:

       Font Name

       fixed

       variable

       5x8

       6x10

       7x13bold

       8x13bold

       9x15bold

       10x20

       12x24

       Browser...

       Font Color

       black

       blue

       cyan

       green

       gray

       red

       magenta

       yellow

       white

       transparent

       Browser...

       Box Color

       black

       blue

       cyan

       green

       gray

       red

       magenta

       yellow

       white

       transparent

       Browser...

       Rotate Text

       -90

       -45

       -30

       0

       30

       45

       90

       180

       Dialog...

       Help

       Dismiss

       Choose  a  font  name  from the Font Name sub-menu. Additional font names can be specified
       with the font browser. You can change the menu names by  setting  the  X  resources  font1
       through font9.

       Choose  a font color from the Font Color sub-menu. Additional font colors can be specified
       with the color browser. You can change the menu colors by setting  the  X  resources  pen1
       through pen9.

       If  you  select  the color browser and press Grab, you can choose the font color by moving
       the pointer to the desired color on the screen and press any button.

       If you choose to rotate the text, choose Rotate Text from the menu and  select  an  angle.
       Typically  you will only want to rotate one line of text at a time. Depending on the angle
       you choose, subsequent lines may end up overwriting each other.

       Choosing a font and its color is optional. The default font is fixed and the default color
       is  black.  However, you must choose a location to begin entering text and press a button.
       An underscore character will appear at the location of the pointer. The cursor changes  to
       a pencil to indicate you are in text mode. To exit immediately, press Dismiss.

       In text mode, any key presses will display the character at the location of the underscore
       and advance the underscore cursor. Enter your text  and  once  completed  press  Apply  to
       finish your image annotation. To correct errors press BACK SPACE. To delete an entire line
       of text, press DELETE.  Any text that exceeds  the  boundaries  of  the  image  window  is
       automatically continued onto the next line.

       The  actual  color you request for the font is saved in the image. However, the color that
       appears in your Image window may be different. For example, on  a  monochrome  screen  the
       text  will  appear  black  or  white  even  if you choose the color red as the font color.
       However, the image saved to a file with -write is written with red  lettering.  To  assure
       the  correct  color  text  in  the  final  image,  any  PseudoClass  image  is promoted to
       DirectClass (see miff(5)). To  force  a  PseudoClass  image  to  remain  PseudoClass,  use
       -colors.

IMAGE COMPOSITING

       An  image  composite  is  created  interactively.  There  is  no  command line argument to
       composite an image. To begin, choose Composite of the Image Edit from the Command  widget.
       Alternatively, press x in the Image window.

       First a popup window is displayed requesting you to enter an image name.  Press Composite,
       Grab or type a file name. Press Cancel if you choose not to create a composite image. When
       you choose Grab, move the pointer to the desired window and press any button.

       If  the Composite image does not have any matte information, you are informed and the file
       browser is displayed again. Enter the name  of  a  mask  image.  The  image  is  typically
       grayscale  and  the same size as the composite image. If the image is not grayscale, it is
       converted to grayscale and the resulting intensities are used as matte information.

       A small window appears showing the location of the cursor in the image window. You are now
       in  composite  mode.  To  exit immediately, press Dismiss.  In composite mode, the Command
       widget has these options:

       Operators

       over

       in

       out

       atop

       xor

       plus

       minus

       add

       subtract

       difference

       bumpmap

       replace

       Blend

       Displace

       Help

       Dismiss

       Choose a composite operation from the Operators sub-menu of the Command widget.  How  each
       operator behaves is described below. image window is the image currently displayed on your
       X server and image is the image obtained

       over    The result is the union of the two image shapes, with image obscuring image window
              in the region of overlap.

       in       The  result  is simply image cut by the shape of image window.  None of the image
              data of image window is in the result.

       out     The resulting image is image with the shape of image window cut out.

       atop    The result is the same shape as image window, with image  obscuring  image  window
              where  the image shapes overlap. Note this differs from over because the portion of
              image outside image window's shape does not appear in the result.

       xor     The result is the image data from both image and image window that is outside  the
              overlap region. The overlap region is blank.

       plus    The result is just the sum of the image data. Output values are cropped to 255 (no
              overflow). This operation is independent of the matte channels.

       minus   The result of image - image window, with underflow  cropped  to  zero.  The  matte
              channel is ignored (set to 255, full coverage).

       add     The result of image + image window, with overflow wrapping around (mod 256).

       subtract
                The result of image - image window, with underflow wrapping around (mod 256). The
              add and subtract operators can be used to perform reversible transformations.

       difference
               The result of abs(image - image window). This is useful  for  comparing  two  very
              similar images.

       bumpmap
               The result of image window shaded by window.

       replace
                The  resulting  image  is  image  window  replaced  with  image.   Here the matte
              information is ignored.

              The image compositor requires a matte, or alpha  channel  in  the  image  for  some
              operations.  This extra channel usually defines a mask which represents a sort of a
              cookie-cutter for the image. This is the case when matte is 255 (full coverage) for
              pixels inside the shape, zero outside, and between zero and 255 on the boundary. If
              image does not have a matte channel,  it  is  initialized  with  0  for  any  pixel
              matching  in  color to pixel location (0,0), otherwise 255. See Matte Editing for a
              method of defining a matte channel.

              If you choose blend, the composite operator becomes over.  The image matte  channel
              percent  transparency is initialized to factor.  The image window is initialized to
              (100-factor). Where factor is the value you specify in the Dialog widget.

              Displace shifts the image pixels as defined  by  a  displacement  map.   With  this
              option, image is used as a displacement map. Black, within the displacement map, is
              a maximum positive displacement. White  is  a  maximum  negative  displacement  and
              middle gray is neutral. The displacement is scaled to determine the pixel shift. By
              default, the displacement applies in both the horizontal and  vertical  directions.
              However,  if  you specify mask, image is the horizontal X displacement and mask the
              vertical Y displacement.

              Note that matte information for image window is  not  retained  for  colormapped  X
              server  visuals  (e.g.  StaticColor, StaticColor, GrayScale, PseudoColor).  Correct
              compositing behavior may require a TrueColor or DirectColor visual  or  a  Standard
              Colormap.

              Choosing  a  composite  operator  is  optional.  The  default  operator is replace.
              However, you must choose a location to composite your image  and  press  button  1.
              Press  and hold the button before releasing and an outline of the image will appear
              to help you identify your location.

              The actual colors of the composite image is saved. However, the color that  appears
              in  image window may be different. For example, on a monochrome screen Image window
              will appear black or white even though your composited image may have many  colors.
              If  the  image  is saved to a file it is written with the correct colors. To assure
              the correct colors are saved in the final image, any PseudoClass image is  promoted
              to DirectClass (see miff).  To force a PseudoClass image to remain PseudoClass, use
              -colors.

COLOR EDITING

       Changing the the color of a set of pixels is performed interactively. There is no  command
       line  argument  to edit a pixel. To begin, choose Color from the Image Edit submenu of the
       Command widget.  Alternatively, press c in the image window.

       A small window appears showing the location of the cursor in the image window. You are now
       in  color  edit mode. To exit immediately, press Dismiss.  In color edit mode, the Command
       widget has these options:

       Method

       point

       replace

       floodfill

       reset

       Pixel Color

       black

       blue

       cyan

       green

       gray

       red

       magenta

       yellow

       white

       Browser...

       Border Color

       black

       blue

       cyan

       green

       gray

       red

       magenta

       yellow

       white

       Browser...

       Fuzz

       0

       2

       4

       8

       16
           Dialog...

       Undo

       Help

       Dismiss

       Choose a color editing method from the Method sub-menu of the Command  widget.  The  point
       method  recolors  any  pixel  selected with the pointer unless the button is released. The
       replace method recolors any pixel that matches the color of the pixel you  select  with  a
       button  press. Floodfill recolors any pixel that matches the color of the pixel you select
       with a button press and is a neighbor.  Whereas filltoborder changes the  matte  value  of
       any  neighbor  pixel that is not the border color.  Finally reset changes the entire image
       to the designated color.

       Next, choose a pixel color from the Pixel Color sub-menu. Additional pixel colors  can  be
       specified  with  the  color  browser.  You  can  change  the  menu colors by setting the X
       resources pen1 through pen9.

       Now press button 1 to select a  pixel  within  the  Image  window  to  change  its  color.
       Additional  pixels  may  be  recolored  as prescribed by the method you choose. additional
       pixels by increasing the Delta value.

       If the Magnify widget is mapped, it can be helpful in positioning your pointer within  the
       image (refer to button 2). Alternatively you can select a pixel to recolor from within the
       Magnify widget. Move the pointer to the Magnify widget and position  the  pixel  with  the
       cursor control keys. Finally, press a button to recolor the selected pixel (or pixels).

       The actual color you request for the pixels is saved in the image. However, the color that
       appears in your Image window may be different. For example, on  a  monochrome  screen  the
       pixel  will  appear  black  or  white even if you choose the color red as the pixel color.
       However, the image saved to a file with -write is written with red pixels. To  assure  the
       correct color text in the final image, any PseudoClass image is promoted to DirectClass To
       force a PseudoClass image to remain PseudoClass, use -colors.

MATTE EDITING

       Matte information within an image is useful for some operations such as image compositing.
       This  extra  channel usually defines a mask which represents a sort of a cookie-cutter for
       the image. This is the case when matte is 255 (full coverage) for pixels inside the shape,
       zero outside, and between zero and 255 on the boundary.

       Setting  the matte information in an image is done interactively. There is no command line
       argument to edit a pixel. To begin, and choose Matte of the Image Edit sub-menu  from  the
       Command widget.

       Alternatively, press m in the image window.

       A small window appears showing the location of the cursor in the image window. You are now
       in matte edit mode. To exit immediately, press Dismiss.  In matte edit mode,  the  Command
       widget has these options:

       Method

       point

       replace

       floodfill

       reset

       Border Color

       black

       blue

       cyan

       green

       gray

       red

       magenta

       yellow

       white

       Browser...

       Fuzz

       0

       2

       4

       8

       16
           Dialog...

       Matte

       Undo

       Help

       Dismiss

       Choose  a  matte  editing method from the Method sub-menu of the Command widget. The point
       method changes the matte value of the any pixel selected with the pointer until the button
       is  released.  The  replace  method  changes the matte value of any pixel that matches the
       color of the pixel you select with a button press. Floodfill changes the  matte  value  of
       any  pixel  that  matches  the  color of the pixel you select with a button press and is a
       neighbor. Whereas filltoborder recolors any neighbor pixel that is not the  border  color.
       Finally  reset changes the entire image to the designated matte value.  Choose Matte Value
       and a dialog appears requesting a matte value.  Enter a value  between  0  and  255.  This
       value  is  assigned  as  the  matte value of the selected pixel or pixels.  Now, press any
       button to select a pixel within the Image window to change its matte value. You can change
       the  matte  value  of  additional pixels by increasing the Delta value. The Delta value is
       first added then subtracted from the red, green, and blue of the target color. Any  pixels
       within the range also have their matte value updated.  If the Magnify widget is mapped, it
       can be helpful in  positioning  your  pointer  within  the  image  (refer  to  button  2).
       Alternatively  you  can  select  a pixel to change the matte value from within the Magnify
       widget.  Move the pointer to the Magnify widget and position the  pixel  with  the  cursor
       control  keys. Finally, press a button to change the matte value of the selected pixel (or
       pixels).  Matte  information  is  only  valid  in  a  DirectClass  image.  Therefore,  any
       PseudoClass  image is promoted to DirectClass. Note that matte information for PseudoClass
       is  not  retained  for  colormapped  X  server  visuals  (e.g.  StaticColor,  StaticColor,
       GrayScale, PseudoColor) unless you immediately save your image to a file (refer to Write).
       Correct matte editing behavior may require a TrueColor or DirectColor visual or a Standard
       Colormap.

IMAGE DRAWING

       An  image  is  drawn  upon  interactively. There is no command line argument to draw on an
       image. To begin, choose  Draw  of  the  Image  Edit  sub-menu  from  the  Command  widget.
       Alternatively, press d in the image window.

       The  cursor  changes to a crosshair to indicate you are in draw mode. To exit immediately,
       press Dismiss. In draw mode, the Command widget has these options:

       Primitive

       point

       line

       rectangle

       fill rectangle

       circle

       fill circle

       ellipse

       fill ellipse

       polygon

       fill polygon

       Color

       black

       blue

       cyan

       green

       gray

       red

       magenta

       yellow

       white

       transparent

       Browser...

       Stipple

       Brick

       Diagonal

       Scales

       Vertical

       Wavy

       Translucent

       Opaque

       Open...

       Width

       1

       2

       4

       8

       16
           Dialog...

       Undo

       Help

       Dismiss

       Choose a drawing primitive from the Primitive sub-menu.

       Next, choose a color from the Color sub-menu. Additional colors can be specified with  the
       color  browser.  You  can  change  the menu colors by setting the X resources pen1 through
       pen9. The transparent color updates the image  matte  channel  and  is  useful  for  image
       compositing.

       If  you  choose  the  color  browser and press Grab, you can select the primitive color by
       moving the pointer to  the  desired  color  on  the  screen  and  press  any  button.  The
       transparent color updates the image matte channel and is useful for image compositing.

       Choose  a  stipple,  if appropriate, from the Stipple sub-menu. Additional stipples can be
       specified with the file browser. Stipples obtained from the file browser must be  on  disk
       in the X11 bitmap format.

       Choose  a  line width, if appropriate, from the Width sub-menu. To choose a specific width
       select the Dialog widget.

       Choose a point in the image window and press button 1 and hold. Next, move the pointer  to
       another  location  in the image. As you move, a line connects the initial location and the
       pointer. When you release the button, the image is updated with  the  primitive  you  just
       drew.  For  polygons,  the  image is updated when you press and release the button without
       moving the pointer.

       To cancel image drawing, move the pointer back to the  starting  point  of  the  line  and
       release the button.

REGION OF INTEREST

       To begin, press choose Region of Interest of the Pixel Transform sub-menu from the Command
       widget.  Alternatively, press R in the image window.

       A small window appears showing the location of the cursor in the image window. You are now
       in  region  of  interest  mode.  In  region of interest mode, the Command widget has these
       options:

       Help

       Dismiss

       To define a region of interest, press button 1 and drag. The region of interest is defined
       by  a  highlighted rectangle that expands or contracts as it follows the pointer. Once you
       are satisfied with the region of interest, release the button. You are now in apply  mode.
       In apply mode the Command widget has these options:

       File

       Save...

       Print...

       Edit

       Undo

       Redo

       Transform

       Flip

       Flop

       Rotate Right

       Rotate Left

       Enhance

       Hue...

       Saturation...

       Brightness...

       Gamma...

       Spiff

       Dull

       Equalize

       Normalize

       Negate

       GRAYscale

       Quantize...

       Effects

       Despeckle

       Emboss

       Reduce Noise

       Add Noise

       Sharpen...

       Blur...

       Threshold...

       Edge Detect...

       Spread...

       Shade...

       Raise...

       Segment...

       F/X

       Solarize...

       Swirl...

       Implode...

       Wave...

       Oil Paint

       Charcoal Draw...

       Miscellany

       Image Info

       Zoom Image

       Show Preview...

       Show Histogram

       Show Matte

       Help

       Dismiss

       You  can  make  adjustments  to the region of interest by moving the pointer to one of the
       rectangle corners, pressing a button, and dragging. Finally, choose  an  image  processing
       technique from the Command widget. You can choose more than one image processing technique
       to apply to an area. Alternatively, you can move the region of  interest  before  applying
       another image processing technique. To exit, press Dismiss.

IMAGE PANNING

       When  an  image  exceeds  the width or height of the X server screen, display maps a small
       panning icon. The rectangle within the panning icon  shows  the  area  that  is  currently
       displayed  in  the the image window. To pan about the image, press any button and drag the
       pointer within the panning icon.  The pan rectangle moves with the pointer and  the  image
       window  is  updated to reflect the location of the rectangle within the panning icon. When
       you have selected the area of the image you wish to view, release the button.

       Use the arrow keys to pan the image one pixel up, down, left, or right  within  the  image
       window.

       The  panning  icon  is withdrawn if the image becomes smaller than the dimensions of the X
       server screen.

USER PREFERENCES

       Preferences affect the default behavior of display(1). The preferences are either true  or
       false and are stored in your home directory as .displayrc:

                display image centered on a backdrop"

                    This  backdrop  covers the entire workstation screen and is useful for hiding
                    other X window activity while viewing the image. The color of the backdrop is
                    specified as the background color. Refer to X Resources for details.
                confirm on program exit"

                    Ask for a confirmation before exiting the display(1) program.
                correct image for display gamma"

                    If the image has a known gamma, the gamma is corrected to match that of the X
                    server (see the X Resource displayGamma).
                display warning messages"

                    Display any warning messages.
                apply Floyd/Steinberg error diffusion to image"

                    The basic strategy of dithering is to trade intensity resolution for  spatial
                    resolution  by  averaging  the  intensities  of  several  neighboring pixels.
                    Images which suffer from  severe  contouring  when  reducing  colors  can  be
                    improved with this preference.
                use a shared colormap for colormapped X visuals"

                    This  option  only applies when the default X server visual is PseudoColor or
                    GRAYScale. Refer to -visual for more details. By default, a  shared  colormap
                    is  allocated.  The  image  shares  colors  with other X clients.  Some image
                    colors could be approximated, therefore your image may  look  very  different
                    than intended. Otherwise the image colors appear exactly as they are defined.
                    However, other  clients  may  go  technicolor  when  the  image  colormap  is
                    installed.
                display images as an X server pixmap"

                    Images  are  maintained  as a XImage by default. Set this resource to True to
                    utilize a server Pixmap instead. This option is useful if your image  exceeds
                    the dimensions of your server screen and you intend to pan the image. Panning
                    is much faster with Pixmaps than with a  XImage.  Pixmaps  are  considered  a
                    precious resource, use them with discretion.

       GM IDENTIFY

              Identify  describes  the  format  and characteristics of one or more image files as
              internally supported by the software. It will also report if an image is incomplete
              or  corrupt.   The  information displayed includes the scene number, the file name,
              the width and height of the image, whether the image is  colormapped  or  not,  the
              number  of colors in the image, the number of bytes in the image, the format of the
              image (JPEG, PNM, etc.), and finally the number of seconds in both  user  time  and
              elapsed  time  it  took  to  read  and process the image.  If -verbose or +ping are
              provided as an option, the pixel read rate  is  also  displayed.  An  example  line
              output from identify follows:

                  images/aquarium.miff 640x480 PseudoClass 256c
                         308135b MIFF 0.000u 0:01

              If -verbose is set, expect additional output including any image comment:

                  Image: images/aquarium.miff
                  class: PseudoClass
                  colors: 256
                  signature: eb5dca81dd93ae7e6ffae99a527eb5dca8...
                  matte: False
                  geometry: 640x480
                     depth: 8
                  bytes: 308135
                  format: MIFF
                  comments:
                  Imported from MTV raster image: aquarium.mtv

              For  some  formats,  additional  format-specific information about the file will be
              written if the -debug coder or -debug all option is used.

IDENTIFY OPTIONS

       Options are processed in command line order. Any option you specify on  the  command  line
       remains in effect for the set of images immediately following, until the set is terminated
       by the appearance of any option or -noop.

       For a more detailed description of each option, see Options, above.

       -authenticate <string>
              decrypt image with this password

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -format <string>
              output formatted image characteristics

       -help  print usage instructions

       -interlace <type>
              the type of interlacing scheme

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -log <string>
              Specify format for debug log

       -ping  efficiently determine image characteristics

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -size <width>x<height>{+offset}
              width and height of the image

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

              For a more detailed description of each option, see Options, above.

GM IMPORT

       Import reads an image from any visible window on an X server and outputs it  as  an  image
       file.  You  can  capture a single window, the entire screen, or any rectangular portion of
       the screen.  Use display for redisplay, printing, editing,  formatting,  archiving,  image
       processing, etc. of the captured image.

       The  target  window can be specified by id, name, or may be selected by clicking the mouse
       in the desired window. If you press a button and then drag, a rectangle  will  form  which
       expands and contracts as the mouse moves. To save the portion of the screen defined by the
       rectangle, just release the button. The keyboard bell is rung once at the beginning of the
       screen capture and twice when it completes.

EXAMPLES

       To  select  an  X  window  or an area of the screen with the mouse and save it in the MIFF
       image format to a file entitled window.miff, use:

           gm import window.miff

       To select an X window or an area of  the  screen  with  the  mouse  and  save  it  in  the
       Encapsulated PostScript format to include in another document, use:

           gm import figure.eps

       To  capture  the  entire  X  server  screen  in  the  JPEG image format in a file entitled
       root.jpeg, without using the mouse, use:

           gm import -window root root.jpeg

       To capture the 512x256 area at the upper right corner of the X server screen  in  the  PNG
       image format in a well-compressed file entitled corner.png, without using the mouse,  use:

           gm import -window root -crop 512x256-0+0 -quality 90
                  corner.png

OPTIONS

       Options  are  processed  in command line order. Any option you specify on the command line
       remains in effect until it is explicitly changed by specifying the  option  again  with  a
       different effect.

       Import  options  can  appear  on  the  command line or in your X resources file. See X(1).
       Options on the command line supersede values specified in your X resources file.

       For a more detailed description of each option, see Options, above.

       -bordercolor <color>
              the border color

       -colors <value>
              preferred number of colors in the image

       -colorspace <value>
              the type of colorspace

       -comment <string>
              annotate an image with a comment

       -crop <width>x<height>{+-}<x>{+-}<y>{%}
              preferred size and location of the cropped image

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -delay <1/100ths of a second>
              display the next image after pausing

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -descend
              obtain image by descending window hierarchy

       -display <host:display[.screen]>
              specifies the X server to contact

       -dispose <method>
              GIF disposal method

       -dither
              apply Floyd/Steinberg error diffusion to the image

       -encoding <type>
              specify the text encoding

       -endian <type>
              specify endianness (MSB, LSB, or Native) of image

       -frame include the X window frame in the imported image

       -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
              Specify dimension, offset, and resize options.

       -help  print usage instructions

       -interlace <type>
              the type of interlacing scheme

       -label <name>
              assign a label to an image

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -log <string>
              Specify format for debug log

       -monitor
              show progress indication

       -monochrome
              transform the image to black and white

       -negate
              replace every pixel with its complementary color

       -page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
              size and location of an image canvas

       -pause <seconds>
              pause between snapshots [import]

       -ping  efficiently determine image characteristics

       -pointsize <value>
              pointsize of the PostScript, X11, or TrueType font

       -quality <value>
              JPEG/MIFF/PNG/TIFF compression level

       -resize <width>x<height>{%}{@}{!}{<}{>}
              resize an image

       -rotate <degrees>{<}{>}
              rotate the image

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -scene <value>
              set scene number

       -screen
              specify the screen to capture

       -set <attribute> <value>
              set an image attribute

       +set <attribute>
              unset an image attribute

       -silent
              operate silently

       -snaps <value>
              number of screen snapshots

       -thumbnail <width>x<height>{%}{@}{!}{<}{>}
              resize an image (quickly)

       -transparent <color>
              make this color transparent within the image

       -trim  trim an image

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

              For a more detailed description of each option, see Options, above.

GM MOGRIFY

       Mogrify transforms an image or a  sequence  of  images.  These  transforms  include  image
       scaling, image rotation, color reduction, and others. Each transmogrified image overwrites
       the corresponding original image, unless an option  such  as  -format  causes  the  output
       filename to be different from the input filename.

       The graphics formats supported by mogrify are listed in GraphicsMagick(1).

EXAMPLES

       To convert all the TIFF files in a particular directory to JPEG, use:

           gm mogrify -format jpeg *.tiff

       To convert a directory full of JPEG images to thumbnails, use:

           gm mogrify -size 120x120 *.jpg -resize 120x120 +profile "*"

       In  this  example,  '-size  120x120'  gives a hint to the JPEG decoder that the images are
       going to be downscaled to 120x120, allowing it to run faster by avoiding  returning  full-
       resolution  images  to GraphicsMagick for the subsequent resizing operation.  The ´-resize
       120x120' specifies the desired dimensions of the output images.  It will be scaled so  its
       largest dimension is 120 pixels.  The ´+profile "*"' removes any ICM, EXIF, IPTC, or other
       profiles that might be present in the input and aren't needed in the thumbnails.

       To scale an image of a cockatoo to exactly 640 pixels in width and 480 pixels  in  height,
       use:

           gm mogrify -resize 640x480! cockatoo.miff

OPTIONS

       Options  are  processed  in command line order. Any option you specify on the command line
       remains in effect for the set of images that follows, until the set is terminated  by  the
       appearance of any option or -noop.

       For a more detailed description of each option, see Options, above.

       -affine <matrix>
              drawing transform matrix

       -antialias
              remove pixel aliasing

       -asc-cdl <spec>
              apply ASC CDL color transform

       -authenticate <string>
              decrypt image with this password

       -auto-orient
              orient (rotate) image so it is upright

       -background <color>
              the background color

       -black-threshold red[,green][,blue][,opacity]
              pixels below the threshold become black

       -blue-primary <x>,<y>
              blue chromaticity primary point

       -blur <radius>{x<sigma>}
              blur the image with a Gaussian operator

       -border <width>x<height>
              surround the image with a border of color

       -bordercolor <color>
              the border color

       -channel <type>
              the type of channel

       -charcoal <factor>
              simulate a charcoal drawing

       -colorize <value>
              colorize the image with the pen color

       -colors <value>
              preferred number of colors in the image

       -colorspace <value>
              the type of colorspace

       -comment <string>
              annotate an image with a comment

       -compose <operator>
              the type of image composition

       -compress <type>
              the type of image compression

       -contrast
              enhance or reduce the image contrast

       -convolve <kernel>
              convolve image with the specified convolution kernel

       -create-directories
              create output directory if required

       -crop <width>x<height>{+-}<x>{+-}<y>{%}
              preferred size and location of the cropped image

       -cycle <amount>
              displace image colormap by amount

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -delay <1/100ths of a second>
              display the next image after pausing

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -despeckle
              reduce the speckles within an image

       -display <host:display[.screen]>
              specifies the X server to contact

       -dispose <method>
              GIF disposal method

       -dither
              apply Floyd/Steinberg error diffusion to the image

       -draw <string>
              annotate an image with one or more graphic primitives

       -edge <radius>
              detect edges within an image

       -emboss <radius>
              emboss an image

       -encoding <type>
              specify the text encoding

       -endian <type>
              specify endianness (MSB, LSB, or Native) of image

       -enhance
              apply a digital filter to enhance a noisy image

       -equalize
              perform histogram equalization to the image

       -extent <width>x<height>{+-}<x>{+-}<y>
              composite image on background color canvas image

       -fill <color>
              color to use when filling a graphic primitive

       -filter <type>
              use this type of filter when resizing an image

       -flip  create a "mirror image"

       -flop  create a "mirror image"

       -font <name>
              use this font when annotating the image with text

       -format <type>
              the image format type

       -frame <width>x<height>+<outer bevel width>+<inner bevel width>
              surround the image with an ornamental border

       -fuzz <distance>{%}
              colors within this Euclidean distance are considered equal

       -gamma <value>
              level of gamma correction

       -gaussian <radius>{x<sigma>}
              blur the image with a Gaussian operator

       -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
              Specify dimension, offset, and resize options.

       -gravity <type>
              direction primitive  gravitates to when annotating the image.

       -green-primary <x>,<y>
              green chromaticity primary point

       -hald-clut <clut>
              apply a Hald CLUT to the image

       -help  print usage instructions

       -implode <factor>
              implode image pixels about the center

       -interlace <type>
              the type of interlacing scheme

       -label <name>
              assign a label to an image

       -lat <width>x<height>{+-}<offset>{%}
              perform local adaptive thresholding

       -level <black_point>{,<gamma>}{,<white_point>}{%}
              adjust the level of image contrast

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -linewidth
              the line width for subsequent draw operations

       -list <type>
              the type of list

       -log <string>
              Specify format for debug log

       -loop <iterations>
              add Netscape loop extension to your GIF animation

       -magnify
              magnify the image

       -map <filename>
              choose a particular set of colors from this image

       -mask <filename>
              Specify a clipping mask

       -matte store matte channel if the image has one

       -mattecolor <color>
              specify the color to be used with the -frame option

       -median <radius>
              apply a median filter to the image

       -minify <factor>
              minify the image

       -modulate brightness[,saturation[,hue]]
              vary the brightness, saturation, and hue of an image

       -monitor
              show progress indication

       -monochrome
              transform the image to black and white

       -motion-blur <radius>{x<sigma>}{+angle}
              Simulate motion blur

       -negate
              replace every pixel with its complementary color

       -noise <radius|type>
              add or reduce noise in an image

       -noop  NOOP (no option)

       -normalize
              transform image to span the full range of color values

       -opaque <color>
              change this color to the pen color within the image

       -operator channel operator rvalue[%]
              apply a mathematical, bitwise, or value operator to an image channel

       -ordered-dither <channeltype> <NxN>
              ordered dither the image

       -output-directory <directory>
              output files to directory

       -orient <orientation>
              Set the image orientation attribute

       -page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
              size and location of an image canvas

       -paint <radius>
              simulate an oil painting

       -pen <color>
              (This option has been replaced by the -fill option)

       -pointsize <value>
              pointsize of the PostScript, X11, or TrueType font

       -profile <filename>
              add ICM, IPTC, or generic profile  to image

       -preserve-timestamp
              preserve the original timestamps of the file

       -quality <value>
              JPEG/MIFF/PNG/TIFF compression level

       -raise <width>x<height>
              lighten or darken image edges

       -random-threshold <channeltype> <LOWxHIGH>
              random threshold the image

       -recolor <matrix>
              apply a color translation matrix to image channels

       -red-primary <x>,<y>
              red chromaticity primary point

       -region <width>x<height>{+-}<x>{+-}<y>
              apply options to a portion of the image

       -render
              render vector operations

       -repage  <width>x<height>+xoff+yoff[!]
              Adjust image page offsets

       -resample <horizontal>x<vertical>
              Resample image to specified horizontal and vertical resolution

       -resize <width>x<height>{%}{@}{!}{<}{>}
              resize an image

       -roll {+-}<x>{+-}<y>
              roll an image vertically or horizontally

       -rotate <degrees>{<}{>}
              rotate the image

       -sample <geometry>
              scale image using pixel sampling

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -scale <geometry>
              scale the image.

       -scene <value>
              set scene number

       -set <attribute> <value>
              set an image attribute

       +set <attribute>
              unset an image attribute

       -segment <cluster threshold>x<smoothing threshold>
              segment an image

       -shade <azimuth>x<elevation>
              shade the image using a distant light source

       -sharpen <radius>{x<sigma>}
              sharpen the image

       -shave <width>x<height>{%}
              shave pixels from the image edges

       -shear <x degrees>x<y degrees>
              shear the image along the X or Y axis

       -size <width>x<height>{+offset}
              width and height of the image

       -solarize <factor>
              negate all pixels above the threshold level

       -spread <amount>
              displace image pixels by a random amount

       -strip remove all profiles and text attributes from the image

       -stroke <color>
              color to use when stroking a graphic primitive

       -strokewidth <value>
              set the stroke width

       -swirl <degrees>
              swirl image pixels about the center

       -texture <filename>
              name of texture to tile onto the image background

       -threshold <value>{%}
              threshold the image

       -thumbnail <width>x<height>{%}{@}{!}{<}{>}
              resize an image (quickly)

       -tile <filename>
              tile image when filling a graphic primitive

       -transform
              transform the image

       -transparent <color>
              make this color transparent within the image

       -treedepth <value>
              tree depth for the color reduction algorithm

       -trim  trim an image

       -type <type>
              the image type

       -units <type>
              the units of image resolution

       -unsharp <radius>{x<sigma>}{+<amount>}{+<threshold>}
              sharpen the image with an unsharp mask operator

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

       -view <string>
              FlashPix viewing parameters

       -virtual-pixel <method>
              specify contents of "virtual pixels"

       -wave <amplitude>x<wavelength>
              alter an image along a sine wave

       -white-point <x>,<y>
              chromaticity white point

       -white-threshold red[,green][,blue][,opacity]
              pixels above the threshold become white

              For a more detailed description of each option, see Options, above.

GM MONTAGE

       montage  creates  a  composite  image by combining several separate images. The images are
       tiled on the composite image with the name of the image optionally  appearing  just  below
       the individual tile.

       The composite image is constructed in the following manner. First, each image specified on
       the command line, except for the last, is scaled to fit the maximum tile size. The maximum
       tile  size  by  default  is  120x120.   It can be modified with the -geometry command line
       argument or X resource. See Options for more information on command  line  arguments.  See
       X(1)  for  more information on X resources.  Note that the maximum tile size need not be a
       square.

       Next the composite image is initialized  with  the  color  specified  by  the  -background
       command  line  argument  or  X  resource.  The  width and height of the composite image is
       determined by the title specified, the maximum tile size, the number of tiles per row, the
       tile  border width and height, the image border width, and the label height. The number of
       tiles per row specifies how many images are to appear in each row of the composite  image.
       The default is to have 5 tiles in each row and 4 tiles in each column of the composite.  A
       specific value is specified with -tile. The tile border width and height,  and  the  image
       border  width defaults to the value of the X resource -borderwidth. It can be changed with
       the -borderwidth or -geometry command line argument or X resource.  The  label  height  is
       determined  by the font you specify with the -font command line argument or X resource. If
       you do not specify a font, a font is chosen that allows the name of the image to  fit  the
       maximum  width  of  a  tiled  area.  The label colors is determined by the -background and
       -fill command line argument or X resource. Note, that if the background and pen colors are
       the same, labels will not appear.

       Initially,  the  composite  image title is placed at the top if one is specified (refer to
       -fill). Next, each image is set onto the composite image, surrounded by its border  color,
       with  its name centered just below it. The individual images are left-justified within the
       width of the tiled area.  The order of the images is  the  same  as  they  appear  on  the
       command  line  unless  the  images have a scene keyword. If a scene number is specified in
       each image, then the images are tiled onto the composite  in  the  order  of  their  scene
       number.  Finally,  the  last  argument  on  the  command  line is the name assigned to the
       composite image. By default, the image is written in the MIFF format and can be viewed  or
       printed with display(1).

       Note,  that  if  the  number  of  tiles exceeds the default number of 20 (5 per row, 4 per
       column), more than one composite image is created. To ensure a single image  is  produced,
       use -tile to increase the number of tiles to meet or exceed the number of input images.

       Finally,  to  create  one  or  more empty spaces in the sequence of tiles, use the "NULL:"
       image format.

       Note, a composite MIFF image displayed to an X server  with  display  behaves  differently
       than  other  images.  You can think of the composite as a visual image directory. Choose a
       particular tile of the composite and press a button to  display  it.  See  display(1)  and
       miff(5)

EXAMPLES

       To  create  a  montage  of  a cockatoo, a parrot, and a hummingbird and write it to a file
       called birds, use:

           gm montage cockatoo.miff parrot.miff hummingbird.miff
                   birds.miff

       To tile several bird images so that they are at most 256 pixels in width and 192 pixels in
       height, surrounded by a red border, and separated by 10 pixels of background color, use:

           gm montage -geometry 256x192+10+10 -bordercolor red
                   birds.* montage.miff

       To  create  an  unlabeled  parrot  image, 640 by 480 pixels, and surrounded by a border of
       black, use:

           gm montage -geometry 640x480 -bordercolor black
                   -label "" parrot.miff bird.miff

       To create an image of an eagle with a textured background, use:

           gm montage -texture bumps.jpg eagle.jpg eagle.png

       To join several GIF images together without any extraneous graphics (e.g.   no  label,  no
       shadowing, no surrounding tile frame), use:

           gm montage +frame +shadow +label -tile 5x1
                   -geometry 50x50+0+0 *.png joined.png

OPTIONS

       Any  option  you  specify  on  the  command line remains in effect for the group of images
       following it, until the group is terminated by the appearance of any option or -noop.  For
       example,  to  make a montage of three images, the first with 32 colors, the second with an
       unlimited number of colors, and the third with only 16 colors, use:

           gm montage -colors 32 cockatoo.1 -noop cockatoo.2
                    -colors 16 cockatoo.3 cockatoos.miff

       For a more detailed description of each option, see Options, above.

       -adjoin
              join images into a single multi-image file

       -affine <matrix>
              drawing transform matrix

       -authenticate <string>
              decrypt image with this password

       -background <color>
              the background color

       -blue-primary <x>,<y>
              blue chromaticity primary point

       -blur <radius>{x<sigma>}
              blur the image with a Gaussian operator

       -bordercolor <color>
              the border color

       -borderwidth <geometry>
              the border width

       -chop <width>x<height>{+-}<x>{+-}<y>{%}
              remove pixels from the interior of an image

       -colors <value>
              preferred number of colors in the image

       -colorspace <value>
              the type of colorspace

       -comment <string>
              annotate an image with a comment

       -compose <operator>
              the type of image composition

       -compress <type>
              the type of image compression

       -crop <width>x<height>{+-}<x>{+-}<y>{%}
              preferred size and location of the cropped image

       -debug <events>
              enable debug printout

       -define <key>{=<value>},...
              add coder/decoder specific options

       -density <width>x<height>
              horizontal and vertical resolution in pixels of the image

       -depth <value>
              depth of the image

       -display <host:display[.screen]>
              specifies the X server to contact

       -dispose <method>
              GIF disposal method

       -dither
              apply Floyd/Steinberg error diffusion to the image

       -draw <string>
              annotate an image with one or more graphic primitives

       -encoding <type>
              specify the text encoding

       -endian <type>
              specify endianness (MSB, LSB, or Native) of image

       -fill <color>
              color to use when filling a graphic primitive

       -filter <type>
              use this type of filter when resizing an image

       -font <name>
              use this font when annotating the image with text

       -frame <width>x<height>+<outer bevel width>+<inner bevel width>
              surround the image with an ornamental border

       -gamma <value>
              level of gamma correction

       -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
              Specify dimension, offset, and resize options.

       -gravity <type>
              direction primitive  gravitates to when annotating the image.

       -green-primary <x>,<y>
              green chromaticity primary point

       -help  print usage instructions

       -interlace <type>
              the type of interlacing scheme

       -label <name>
              assign a label to an image

       -limit <type> <value>
              Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit

       -log <string>
              Specify format for debug log

       -matte store matte channel if the image has one

       -mattecolor <color>
              specify the color to be used with the -frame option

       -mode <value>
              mode of operation

       -monitor
              show progress indication

       -monochrome
              transform the image to black and white

       -noop  NOOP (no option)

       -page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
              size and location of an image canvas

       -pen <color>
              (This option has been replaced by the -fill option)

       -pointsize <value>
              pointsize of the PostScript, X11, or TrueType font

       -quality <value>
              JPEG/MIFF/PNG/TIFF compression level

       -red-primary <x>,<y>
              red chromaticity primary point

       -render
              render vector operations

       -repage  <width>x<height>+xoff+yoff[!]
              Adjust image page offsets

       -resize <width>x<height>{%}{@}{!}{<}{>}
              resize an image

       -rotate <degrees>{<}{>}
              rotate the image

       -sampling-factor <horizontal_factor>x<vertical_factor>
              chroma subsampling factors

       -scenes <value-value>
              range of image scene numbers to read

       -shadow <radius>{x<sigma>}
              shadow the montage

       -sharpen <radius>{x<sigma>}
              sharpen the image

       -size <width>x<height>{+offset}
              width and height of the image

       -strip remove all profiles and text attributes from the image

       -stroke <color>
              color to use when stroking a graphic primitive

       -strokewidth <value>
              set the stroke width

       -texture <filename>
              name of texture to tile onto the image background

       -thumbnail <width>x<height>{%}{@}{!}{<}{>}
              resize an image (quickly)

       -tile <geometry>
              layout of images [montage]

       -title <string>
              assign title to displayed image [animate, display, montage]

       -transform
              transform the image

       -transparent <color>
              make this color transparent within the image

       -treedepth <value>
              tree depth for the color reduction algorithm

       -trim  trim an image

       -type <type>
              the image type

       -verbose
              print detailed information about the image

       -version
              print GraphicsMagick version string

       -white-point <x>,<y>
              chromaticity white point

              For a more detailed description of each option, see Options, above.

X RESOURCES

       Montage options can appear on the command line or in your X resource file. Options on  the
       command  line  supersede  values  specified  in  your  X  resource file. See X(1) for more
       information on X resources.

       All montage options have a  corresponding  X  resource.  In  addition,  montage  uses  the
       following X resources:

       background (class Background)
              background color

              Specifies  the  preferred  color  to  use  for the composite image background.  The
              default is #ccc.

       borderColor (class BorderColor)
              border color

              Specifies the preferred color to use for the composite image border. The default is
              #ccc.

       borderWidth (class BorderWidth)
              border width

              Specifies the width in pixels of the composite image border. The default is 2.

       font (class Font)
              font to use

              Specifies  the  name  of  the preferred font to use when displaying text within the
              composite image. The default is 9x15, fixed, or 5x8  determined  by  the  composite
              image size.

       matteColor (class MatteColor)
              color of the frame

              Specify the color of an image frame. A 3D effect is achieved by using highlight and
              shadow colors derived from this color. The default value is #697B8F.

       pen (class Pen)
              text color

              Specifies the preferred color to use for text  within  the  composite  image.   The
              default is black.

       title (class Title)
              composite image title

              This  resource  specifies the title to be placed at the top of the composite image.
              The default is not to place a title at the top of the composite image.

GM TIME

DESCRIPTION

       time executes an arbitrary gm utility command (e.g. convert)  and  reports  the  user  and
       elapsed  time.   This  provides way to measure command execution times similar to the Unix
       ´time' command but in a portable and consistent way.

EXAMPLES

       To obtain time information for the execution of a command:

       % gm time convert input.ppm -gaussian 0x2 output.ppm
       convert input.ppm -gaussian 0x2 output.ppm    22.60s user 0.00s system 2354% cpu 0.960 total
       Here is the interpretation of the above output:

           user - the total user time consumed.
           system - the total system time consumed.
           total - the total elapsed time consumed.

OPTIONS

       The time command reqires no options other than the gm command to execute.

GM VERSION

DESCRIPTION

       version displays the software release version, build quantum  (pixel  sample)  depth,  web
       site  URL, copyright notice, enabled features support, configuration parameters, and final
       build options used to build the software.  The available information depends  on  how  the
       software was configured and the host system.

EXAMPLES

       To display the version information:

         GraphicsMagick 1.3.37 2021-12-12 Q16 http://www.GraphicsMagick.org/
         Copyright (C) 2002-2021 GraphicsMagick Group.
         Additional copyrights and licenses apply to this software.
         See http://www.GraphicsMagick.org/www/Copyright.html for details.
         Feature Support:
           Native Thread Safe         yes
           Large Files (> 32 bit)     yes
           Large Memory (> 32 bit)    yes
           BZIP                       yes
           DPS                        no
           FlashPix                   no
           FreeType                   yes
           Ghostscript (Library)      no
           JBIG                       yes
           JPEG-2000                  yes
           JPEG                       yes
           Little CMS                 yes
           Loadable Modules           no
           Solaris mtmalloc           no
           Google perftools tcmalloc  no
           OpenMP                     yes (201511 "4.5")
           PNG                        yes
           TIFF                       yes
           TRIO                       no
           Solaris umem               no
           WebP                       yes
           WMF                        yes
           X11                        yes
           XML                        yes
           ZLIB                       yes
         Host type: x86_64-unknown-linux-gnu
         Configured using the command:
           ./configure  ...
         Final Build Parameters:
           CC       = ...
           CFLAGS   = ...
           CPPFLAGS = ...
           CXX      = ...
           CXXFLAGS = ...
           LDFLAGS  = ...
           LIBS     = ...

OPTIONS

       The version command does not currently support any options.