Provided by: gifsicle_1.88-1_amd64 bug


       gifsicle - manipulates GIF images and animations


       gifsicle [options, frames, and filenames]...


       gifsicle  is  a  powerful  command-line  program  for creating, editing, manipulating, and
       getting information about GIF images and animations.

       Gifsicle normally processes input GIF files according to  its  command  line  options  and
       writes  the  result  to the standard output. The -i option, for example, tells gifsicle to
       interlace its inputs:

            gifsicle -i < pic.gif > interlaced-pic.gif

       Gifsicle is good at creating and manipulating GIF animations. By default, it combines  two
       or more input files into a “flipbook” animation:

            gifsicle pic1.gif pic2.gif pic3.gif > animation.gif

       Use options like --delay, --loopcount, and --optimize to tune your animations.

       To  modify  GIF files in place, use the --batch option. With --batch, gifsicle will modify
       the files you specify instead of writing a new file to the standard output.  To  interlace
       all the GIFs in the current directory, you could say:

            gifsicle --batch -i *.gif

       New users may want to skip to the Examples section at the end.


       Concepts are on the left, relevant gifsicle options are on the right.

       Animations, changing     frame selections, frame changes, etc.
          disposal              --disposal
          looping               --loopcount
          portions of           frame selections
          smaller               --optimize, --colors
          speed                 --delay
       Bad output               --careful
       Background color         --background
       Colors, changing         --change-color, --use-colormap, --dither, --transform-colormap
          reducing number       --colors, --dither, --gamma
       Comments                 --comment
       Extensions               --extension, --app-extension, --extension-info
       File size                --optimize, --unoptimize, --colors
       Image transformations
          cropping              --crop, --crop-transparency
          flipping              --flip-*
          resizing              --resize, --scale
          rotating              --rotate-*
       Grayscale                --use-colormap
       Interlacing              --interlace
       Positioning frames       --position
       Screen, logical          --logical-screen
       Selecting frames         frame selections (like '#0')
       Transparency             --transparent
       Warnings                 --no-warnings


       gifsicle's command line consists of GIF input files and options. Most options start with a
       dash (-) or plus (+); frame selections, a kind of option, start with a  number  sign  (#).
       Anything else is a GIF input file.

       gifsicle  reads  and processes GIF input files in order. If no GIF input file is given, or
       you give the special filename ‘-’, it reads from the standard input.

       gifsicle exits with status 0 if there were no errors and status 1 otherwise.


       Every option has a long form, ‘--long-descriptive-name’.  You don't need to type the whole
       long descriptive name, just enough to make it unambiguous.

       Some  options  also  have a short form, ‘-X’.  You can combine short options if they don't
       take arguments: ‘-IIb’ is the same as ‘-I -I -b’.  But be careful  with  options  that  do
       take arguments: ‘-cblah’ means ‘-c blah’, not ‘-c -b -l -a -h’.

       Many options also have a converse, ‘--no-option’, which turns off the option. You can turn
       off a short option ‘-X’ by saying ‘+X’ instead.

   Mode Options
       Mode options tell gifsicle what kind of output to generate. There can be at most one,  and
       it must precede any GIF inputs.

       --merge, -m
            Combine  all GIF inputs into one file with multiple frames and write that file to the
            standard output. This is the default mode.

       --batch, -b
            Modify each GIF input in place by reading and writing to the  same  filename.   (GIFs
            read from the standard input are written to the standard output.)

       --explode, -e
            Create  an  output  GIF  for each frame of each input file. The output GIFs are named
            ‘xxx.000’, ‘xxx.001’, and so on, where ‘xxx’ is  the  name  of  the  input  file  (or
            whatever  you  specified  with  ‘--output’)  and  the  numeric extension is the frame

       --explode-by-name, -E
            Same as --explode, but  write  any  named  frames  to  files  ‘’  instead  of
            ‘xxx.frame-number’.  Frames are named using the ‘--name’ option.

   General Options
       General  options  control  the information gifsicle prints and where it writes its output.
       The info options and --verbose can be turned off with ‘--no-X’.

       --info, -I
            Print a human-readable description of each input  GIF  to  the  standard  output,  or
            whatever  file you specify with -o.  This option suppresses normal output, and cannot
            be combined with mode options like --batch.  If you give two --info  or  -I  options,
            however,  information  is printed to standard error, and normal output takes place as

       --color-info, --cinfo
            Like --info, but also print information about input files' colormaps.

       --extension-info, --xinfo
            Like --info, but also print any unrecognized  GIF  extensions  in  a  hexdump(1)-like

       --size-info, --sinfo
            Like --info, but also print information about compressed image sizes.

       --help, -h
            Print usage information and exit.

       -o file
       --output file
            Send output to file.  The special filename ‘-’ means the standard output.

       --verbose, -V
            Print progress information (files read and written) to standard error.

       --no-warnings, -w
            Suppress all warning messages.

            Exit with status 1 when encountering a very erroneous GIF. Default is to muddle on.

            Print the version number and some short non-warranty information and exit.

            Write  slightly  larger  GIFs that avoid bugs in some other GIF implementations. Some
            Java and Internet Explorer versions cannot display the  correct,  minimal  GIFs  that
            Gifsicle  produces.  Use  the  --careful  option  if  you  are having problems with a
            particular image.

            Conserve memory usage at the expense of processing time. This may be  useful  if  you
            are processing large GIFs on a computer without very much memory.

            Allow  input files to contain multiple concatenated GIF images. If a filename appears
            multiple times on the command line, gifsicle will read a new image from the file each
            time.  This  option can help scripts avoid the need for temporary files. For example,
            to create an animated GIF with three frames with  different  delays,  you  might  run
            "gifsicle  --nextfile -d10 - -d20 - -d30 - > out.gif" and write the three GIF images,
            in sequence, to gifsicle's standard input.

            Like --nextfile, but read as many GIF images as possible from each file. This  option
            is intended for scripts. For example, to merge an unknown number of GIF images into a
            single animation, run "gifsicle --multifile - > out.gif" and write the GIF images, in
            sequence,  to gifsicle's standard input.  Any frame selections apply only to the last
            file in the concatenation.

   Frame Selections
       A frame selection tells gifsicle which frames to use from the current input file. They are
       useful  only  for  animations,  as  non-animated  GIFs  only  have one frame. Here are the
       acceptable forms for frame specifications.

       #num         Select frame num. (The first frame is ‘#0’.  Negative numbers count backwards
                    from the last frame, which is ‘#-1’.)
       #num1-num2   Select frames num1 through num2.
       #num1-       Select frames num1 through the last frame.
       #name        Select the frame named name.

       The ‘#’ character has special meaning for many shells, so you generally need to quote it.

       For example,
            gifsicle happy.gif "#0"
       uses the first frame from happy.gif;
            gifsicle happy.gif "#0-2"
       uses its first three frames; and
            gifsicle happy.gif "#-1-0"
       uses  its frames in reverse order (starting from frame #-1 -- the last frame -- and ending
       at frame #0 -- the first).

       The action performed with the selected frames depends on the current mode. In merge  mode,
       only  the selected frames are merged into the output GIF. In batch mode, only the selected
       frames are modified; other frames remain unchanged. In explode  mode,  only  the  selected
       frames are exploded into output GIFs.

   Frame Change Options
       Frame  change options insert new frames into an animation or replace or delete frames that
       already exist. Some things -- for example, changing one  frame  in  an  animation  --  are
       difficult to express with frame selections, but easy with frame changes.

       --delete frames [frames...]
            Delete frames from the input GIF.

       --insert-before frame other-GIFs
            Insert other-GIFs before frame in the input GIF.

       --append other-GIFs
            Append other-GIFs to the input GIF.

       --replace frames other-GIFs
            Replace frames from the input GIF with other-GIFs.

            Complete the current set of frame changes.

       The  frames  arguments  are  frame selections (see above). These arguments always refer to
       frames from the original input GIF. So, if ‘a.gif’ has 3 frames and ‘b.gif’ has one,  this
            gifsicle a.gif --delete "#0" --replace "#2" b.gif
       will produce an output animation with 2 frames: ‘a.gif’ frame 1, then ‘b.gif’.

       The  other-GIFs  arguments  are any number of GIF input files and frame selections.  These
       images are combined in merge mode and added to the input GIF.  The other-GIFs  last  until
       the  next  frame  change option, so this command replaces the first frame of ‘in.gif’ with
       the merge of ‘a.gif’ and ‘b.gif’:
            gifsicle -b in.gif --replace "#0" a.gif b.gif

       This command, however, replaces  the  first  frame  of  ‘in.gif’  with  ‘a.gif’  and  then
       processes ‘b.gif’ separately:
            gifsicle -b in.gif --replace "#0" a.gif --done b.gif

       Warning: You shouldn't use both frame selections and frame changes on the same input GIF.

   Image Options
       Image  options  modify  input  images  -- by changing their interlacing, transparency, and
       cropping, for example. Image options have three forms: ‘--X’,  ‘--no-X’,  and  ‘--same-X’.
       The  ‘--X’  form selects a value for the feature, the ‘--no-X’ form turns off the feature,
       and the ‘--same-X’ form means that the feature's value is  copied  from  each  input.  The
       default  is  always  ‘--same-X’.   For  example, -background="#0000FF" sets the background
       color to blue, --no-background turns the background color off (by setting it  to  0),  and
       --same-background  uses input images' existing background colors. You can give each option
       multiple times; for example,
            gifsicle -b -O2 -i a.gif --same-interlace b.gif c.gif
       will make ‘a.gif’ interlaced, but leave ‘b.gif’ and ‘c.gif’ interlaced only if  they  were

       -B color
       --background color
            Set the output GIF's background to color.  The argument can have the same forms as in
            the --transparent option below.

       --crop x1,y1-x2,y2
       --crop x1,y1+widthxheight
            Crop the following input frames to a smaller rectangular area. The top-left corner of
            this  rectangle  is  (x1,y1); you can give either the lower-right corner, (x2,y2), or
            the width and height of the rectangle. In  the  x1,y1+widthxheight  form,  width  and
            height  can be zero or negative. A zero dimension means the cropping area goes to the
            edge of the image; a negative dimension brings the cropping  area  that  many  pixels
            back  from the image edge. For example, --crop 2,2+-2x-2 will shave 2 pixels off each
            side of the  input  image.  Cropping  takes  place  before  any  rotation,  flipping,
            resizing, or positioning.

            Crop  any  transparent borders off the following input frames. This happens after any
            cropping due to the --crop option. It works on the raw input images; for example, any
            transparency options have not yet been applied.

            Flip the following frames horizontally or vertically.

            Turn interlacing on.

       -S widthxheight
       --logical-screen widthxheight
            Set  the  output logical screen to widthxheight.  --no-logical-screen sets the output
            logical screen to the size of the largest output frame,  while  --same-logical-screen
            sets  the  output  logical screen to the largest input logical screen.  --screen is a
            synonym for --logical-screen.

       -p x,y
       --position x,y
            Set the following frames' positions to (x,y).  --no-position  means  --position  0,0.
            Normally, --position x,y places every succeeding frame exactly at x,y. However, if an
            entire animation is input, x,y is treated as the position for the animation.

            Rotate the following frames by 90, 180, or 270 degrees.  --no-rotate  turns  off  any

       -t color
       --transparent color
            Make  color  transparent  in  the  following  frames.   Color can be a colormap index
            (0-255), a hexadecimal color specification (like "#FF00FF" for magenta), or slash- or
            comma-separated red, green and blue values (each between 0 and 255).

   Extension Options
       Extension  options  add  non-visual  information  to  the output GIF. This includes names,
       comments, and generic extensions.

       --app-extension app-name extension
            Add an application extension named app-name and  with  the  value  extension  to  the
            output  GIF.   --no-app-extensions  removes  application  extensions  from  the input

       -c text
       --comment text
            Add a comment, text, to the output GIF. The comment will be placed  before  the  next
            frame in the stream.  --no-comments removes comments from the input images.

       --extension number extension
            Add  an  extension  numbered  number  and with the value extension to the output GIF.
            Number can be in decimal, octal, hex, or it can be a single character like ‘n’, whose
            ASCII  value  is  used.   --no-extensions  (or  +x) removes extensions from the input

       -n text
       --name text
            Set the next frame's name to text.  This name is stored as an extension in the output
            GIF  (extension  number  0xCE,  followed  by  the  characters  of  the  frame  name).
            --no-names removes name extensions from the input images.

   Animation Options
       Animation options apply to GIF animations, or to individual frames in GIF  animations.  As
       with  image  options,  most  animation  options  have  three  forms,  ‘--X’, ‘--no-X’, and
       ‘--same-X’, and you can give animation options multiple times; for example,
            gifsicle -b a.gif -d50 "#0" "#1" -d100 "#2" "#3"
       sets the delays of frames 0 and 1 to 50, and frames 2 and 3 to 100.

       -d time
       --delay time
            Set the delay between frames to time in hundredths of a second.

       -D method
       --disposal method
            Set the disposal method for the following  frames  to  method.   A  frame's  disposal
            method  determines how a viewer should remove the frame when it's time to display the
            next.  Method can be a number between  0  and  7  (although  only  0  through  3  are
            generally  meaningful),  or  one  of  these  names: none (leave the frame visible for
            future frames to build upon), asis (same as "none"), background (or bg) (replace  the
            frame  with  the  background),  or previous (replace the frame with the area from the
            previous displayed frame).  --no-disposal means --disposal=none.

            Set the Netscape loop extension to count.  Count is an integer, or  forever  to  loop
            endlessly. If you supply a --loopcount option without specifying count, Gifsicle will
            use forever.  --no-loopcount (the default) turns off looping.

            Set the loop count to one less than the number of times you  want  the  animation  to
            run.  An animation with --no-loopcount will show every frame once; --loopcount=1 will
            loop once, thus showing every frame twice; and so forth.  Note that --loopcount=0  is
            equivalent to --loopcount=forever, not --no-loopcount.

            Optimize  output GIF animations for space.  Level determines how much optimization is
            done; higher levels take longer, but may have better  results.  There  are  currently
            three levels:

            -O1  Stores only the changed portion of each image. This is the default.
            -O2  Also uses transparency to shrink the file further.
            -O3  Try several optimization methods (usually slower, sometimes better results).

            Other optimization flags provide finer-grained control.

                 Preserve empty transparent frames (they are dropped by default).

            You  may  also  be  interested  in  other  options for shrinking GIFs, such as -k and

            Unoptimize GIF animations into an easy-to-edit form.

            GIF animations are often optimized (see --optimize) to make them smaller  and  faster
            to  load,  which  unfortunately  makes  them difficult to edit.  --unoptimize changes
            optimized  input  GIFs  into  unoptimized  GIFs,  where  each  frame  is  a  faithful
            representation of what a user would see at that point in the animation.

   Image Transformation Options
       Image transformation options apply to entire GIFs as they are read or written. They can be
       turned off with ‘--no-option’.

       --resize widthxheight
            Resize the output GIF to widthxheight.  Either width or height may be  an  underscore
            ‘_’.  If  the argument is widthx_, then the output GIF is scaled to width pixels wide
            without changing its aspect ratio. An analogous operation is performed for  _xheight.
            Resizing  happens  after all input frames have been combined and before optimization.
            Resizing uses logical screen dimensions; if the input stream has an  unusual  logical
            screen  (many  GIF  displayers  ignore  logical  screens),  you  may  want to provide
            --no-logical-screen (or +S) to reset it so gifsicle uses  image  dimensions  instead.
            See also --resize-method.

       --resize-width width
       --resize-height height
            Like --resize widthx_ and --resize _xheight respectively.

       --resize-fit widthxheight
            Like  --resize,  but resizes the output GIF to fit within a rectangle with dimensions
            widthxheight.  The GIF's aspect ratio remains unchanged. No resize  is  performed  if
            the  GIF  already  fits  within the given rectangle. Either width or height may be an
            underscore ‘_’, which is treated as infinity.

       --resize-fit-width width
       --resize-fit-height height
            Like --resize-fit widthx_ and --resize-fit _xheight respectively.

       --scale Xfactor[xYfactor]
            Scale the output GIF's width and height by Xfactor and Yfactor.  If  Yfactor  is  not
            given,  it  defaults  to  Xfactor.   Scaling happens after all input frames have been
            combined and before optimization.

       --resize-method method
            Set the method used to resize images. The ‘sample’ method runs very quickly, but when
            shrinking  images,  it  produces noisy results.  The ‘mix’ method is somewhat slower,
            but produces better-looking results. The default method is currently ‘mix’.

            Details: The resize methods differ most when shrinking images. The ‘sample’ method is
            a  point  sampler.  Each pixel position in the output image maps to exactly one pixel
            position in the input, so when shrinking, full rows and columns from  the  input  are
            dropped.  The  other  methods  use all input pixels, which generally produces better-
            looking images. The ‘box’ method, a box sampler, is  faster  than  the  more  complex
            filters  and  produces  somewhat  sharper  results,  but there will be anomalies when
            shrinking images by a small amount  in  one  dimension.   (Some  output  pixels  will
            correspond  to exactly 1 input row or column, while others will correspond to exactly
            2 input rows or columns.) The ‘mix’ method is a full bilinear interpolator.  This  is
            slower and produces somewhat blurrier results, but avoids such anomalies.

            Gifsicle  also  supports  several  complex  resamplers,  including  Catmull-Rom cubic
            resampling (‘catrom’), the Mitchell-Netravali filter (‘mitchell’), a 2-lobed  Lanczos
            filter  (‘lanczos2’),  and  a 3-lobed Lanczos filter (‘lanczos3’).  These filters are
            slower still, but can give sharper, better results.

       --resize-colors n
            Allow Gifsicle to add intermediate colors when resizing images.  Normally, Gifsicle's
            resize  algorithms  use  input images' color palettes without changes. When shrinking
            images with very few colors (e.g., pure black-and-white images), adding  intermediate
            colors  can  improve  the results. Example: --resize-colors 64 allows Gifsicle to add
            intermediate colors for images that have fewer than 64 input colors.

   Color Options
       Color options apply to entire GIFs as they are read or written. They  can  be  turned  off
       with ‘--no-option’.

       -k num
       --colors num
            Reduce  the number of distinct colors in each output GIF to num or less.  Num must be
            between 2 and 256. This can be used to shrink output  GIFs  or  eliminate  any  local
            color tables.

            Normally,  an  adaptive  group of colors is chosen from the existing color table. You
            can affect this process with the --color-method option or by giving your own colormap
            with  --use-colormap.   Gifsicle may need to add an additional color (making num+1 in
            all) if there is transparency in the image.

       --color-method method
            Determine how a smaller colormap is chosen.  ‘diversity’,  the  default,  is  xv(1)'s
            diversity  algorithm, which uses a strict subset of the existing colors and generally
            produces good results.  ‘blend-diversity’ is  a  modification  of  this:  some  color
            values  are  blended  from groups of existing colors.  ‘median-cut’ is the median cut
            algorithm described by Heckbert.  --method is a synonym for --color-method.

            When --dither is on and the colormap is changed, combinations of colors are  used  to
            approximate  missing  colors. This looks better, but makes bigger files and can cause
            animation artifacts, so it is off by default.

            Specify a dithering algorithm  with  the  optional  method  argument.   The  default,
            ‘floyd-steinberg’, uses Floyd-Steinberg error diffusion. This usually looks best, but
            can cause animation artifacts, because dithering choices  will  vary  from  frame  to
            frame.  Gifsicle  also  supports  ordered  dithering  algorithms that avoid animation
            artifacts.  The ‘ro64’ mode  uses  a  large,  random-looking  pattern  and  generally
            produces  good  results.  The  ‘o3’,  ‘o4’,  and ‘o8’ modes use smaller, more regular
            patterns. The ‘ordered’ mode chooses a good ordered dithering algorithm. For  special
            effects,  try  the halftone modes ‘halftone’, ‘squarehalftone’, and ‘diagonal’.  Some
            modes take optional parameters using commas. The halftone modes take a cell size  and
            a  color  limit: ‘halftone,10,3’ creates 10-pixel wide halftone cells where each cell
            uses up to 3 colors.

       --gamma gamma
            Set the gamma correction to gamma, which can be a real  number  or  ‘srgb’.   Roughly
            speaking,  higher numbers exaggerate shadows and lower numbers exaggerate highlights.
            The default is the function defined by the standard sRGB color space,  which  usually
            works  well. (Its effects are similar to --gamma=2.2.) Gifsicle uses gamma correction
            when choosing a color palette (--colors) and when dithering (--dither).

       --change-color color1 color2
            Change color1 to color2 in the following input GIFs. (The color  arguments  have  the
            same forms as in the -t option.) Change multiple colors by giving the option multiple
            times. Color changes don't interfere with one another, so you  can  safely  swap  two
            colors  with  ‘--change-color  color1 color2 --change-color color2 color1’.  They all
            take effect as an input GIF is read.  --no-change-color cancels all color changes.

       --transform-colormap command
            Command should be a shell command that  reads  from  standard  input  and  writes  to
            standard  output.  Each  colormap  in the output GIF is translated into text colormap
            format (see --use-colormap below) and piped to the command. The output  that  command
            generates  (which  should  also  be  in  text colormap format) will replace the input
            colormap. The replacement doesn't consider color matching, so pixels that used  color
            slot n in the input will still use color slot n in the output.

       --use-colormap colormap
            Change  the image to use colormap.  Each pixel in the image is changed to the closest
            match in colormap (or, if --dither is on, to a  dithered  combination  of  colors  in
            colormap).   Colormap  can  be  web  for  the  216-color “Web-safe palette”; gray for
            grayscale; bw for black-and-white; or the name of a file. That file should either  be
            a text file (the format is described below) or a GIF file, whose global colormap will
            be used. If --colors=N is also given, an N-sized subset of colormap will be used.

            Text colormap files use this format:

            ; each non-comment line represents one color, "red green blue"
            ; each component should be between 0 and 255
            0 0 0            ; like this
            255 255 255
            ; or use web hex notation
            #ffffff          ; like this


       First, let's create an animation, ‘anim.gif’:

            gifsicle a.gif b.gif c.gif d.gif > anim.gif

       This animation will move very quickly: since we didn't specify a  delay,  a  browser  will
       cycle  through  the  frames  as  fast  as  it can. Let's slow it down and pause .5 seconds
       between frames, using the --delay option.

            gifsicle --delay 50 a.gif b.gif c.gif d.gif > anim.gif

       If we also want the GIF to loop three times, we can use --loopcount:

            gifsicle -d 50 --loop=3 a.gif b.gif c.gif d.gif > anim.gif

       (Rather than type --delay again, we used its short form,  -d.   Many  options  have  short
       forms;  you can see them by running ‘gifsicle --help’.  We also abbreviated --loopcount to
       --loop, which is OK since no other option starts with ‘loop’.)

       To explode ‘anim.gif’ into its component frames:

            gifsicle --explode anim.gif
            ls anim.gif*
            anim.gif  anim.gif.000  anim.gif.001  anim.gif.002  anim.gif.003

       To optimize ‘anim.gif’:

            gifsicle -b -O2 anim.gif

       To change the second frame of ‘anim.gif’ to ‘x.gif’:

            gifsicle -b --unoptimize -O2 anim.gif --replace "#1" x.gif

       --unoptimize is used since ‘anim.gif’ was optimized in the last step.  Editing  individual
       frames  in  optimized GIFs is dangerous without --unoptimize; frames following the changed
       frame could be corrupted by the change.  Of course, this might be what you want.

       Note that --unoptimize and --optimize can  be  on  simultaneously.   --unoptimize  affects
       input GIF files, while --optimize affects output GIF files.

       To print information about the first and fourth frames of ‘anim.gif’:

            gifsicle -I "#0" "#3" < anim.gif

       To  make  black  the  transparent color in all the GIFs in the current directory, and also
       print information about each:

            gifsicle -bII --trans "#000000" *.gif

       Giving -I twice forces normal output to occur. With only one -I, the  GIFs  would  not  be

       To change ‘anim.gif’ to use a 64-color subset of the Web-safe palette:

            gifsicle -b --colors=64 --use-col=web anim.gif

       To make a dithered black-and-white version of ‘anim.gif’:

            gifsicle --dither --use-col=bw anim.gif > anim-bw.gif

       To  overlay  one  GIF atop another -- producing a one-frame output GIF that looks like the
       superposition of the two inputs -- use gifsicle twice:

            gifsicle bottom.gif top.gif | gifsicle -U "#1" > result.gif


       Some optimized output GIFs  may  appear  incorrectly  on  some  GIF  implementations  (for
       example, Java's); see the --careful option.

       Please email suggestions, additions, patches and bugs to


       For  a  tutorial  on GIF images and animations, you might try some of the resources listed
       on-line at


       Eddie Kohler <>
       He wrote it.

       Anne Dudfield <>
       She named it.

       Hans Dinsen-Hansen <>
       Adaptive tree method for GIF writing.
       The gifsicle home page.