Provided by: xcftools_1.0.7-3ubuntu1_amd64 bug

NAME

       xcf2pnm - convert from GIMP xcf files to ppm/pgm/pbm format

SYNOPSIS

       xcf2pnm [ options ] filename [ layer names ]

DESCRIPTION

       xcf2pnm is a command-line tool that converts image files in the XCF format used by gimp(1)
       to the generic image formats pbm(5), pgm(5), and ppm(5), flattening layers  if  necessary.
       It does not need to have the Gimp engine itself available.

GENERAL OPTIONS

       -a filename, --alpha filename
               Output  a  transparency mask for the flattened image to filename as a pgm(5) file,
               in addition to the ordinary output.  If the flattened image is completely  opaque,
               this will produce an error message and exit status 101; use -A to suppress this.

       -A, --force-alpha
               Invent a trivial alpha channel even if the flattened image is completely opaque.

       -b color, --background color
               Use  this  color  for  transparent pixels in the image.  The color can be given as
               #rrggbb or #rgb hexadecimal values, or as an X11 color name (which will only  work
               if a color name database can be found in one of a number of standard locations).

       -c, --color, --colour
               Force  the  output  to  use  RGB  color  space  even  if it there are more compact
               alternatives.  This will be selected automatically if the output file's name  ends
               with .ppm.

       -C, --autocrop
               Set  the  converted  part of the image such that it just include the boundaries of
               the visible (or selected) layers.  This may make it either smaller or larger  than
               the  canvas, depending on the position and size of the visible layers.  (Note that
               the contents of the layers is not taken into account when autocropping).

               In the absence of options that specify otherwise, the converted image  will  cover
               the entire XCF canvas.

       -D, --dissolve
               Do a "dissolve" step to eliminate partial transparency after flattening.  If -b is
               also given, this happens before the background color is applied.

       -f, --full-image
               First flatten the entire image to a memory  buffer  before  writing  output.  Then
               analyse  the  image to decide on the details of the output format (e.g., whether a
               grayscale output is sufficient).  Without this option, the program flattens only a
               singe row of "tiles" (height 64) at a time.

       -g, --gray, --grey
               Force  the  output  to  be a grayscale image even if it may be monochrome.  If any
               colored pixels are encountered, exit with  status  103.   This  will  be  selected
               automatically if the output file's name ends with .pgm.

       -G, --for-gif
               Assert that the flattened image will have no partial transparency (allowing a more
               compact representation of  the  alpha  output).   Exit  with  status  102  if  the
               flattened  image  has  any  partial transparency.  If -b is also given, this tests
               whether there there is partial transparency before applying the background color.

       -h, --help
               Print an option summery to standard output and exit with a return code of 0.

       -j, --bzip
               Equivalent to -Z bzcat.  Default if the filename ends with bz2.

       -m, --mono
               Force the output to be a monochrome image.  If any colors except black  and  white
               are encountered, exit with status 103.  This will be selected automatically if the
               output file's name ends with .pbm.

       -n, --pnm
               Suppress the automatic choice of -c, -g, or  -m  based  on  output  filename,  and
               instead  select the output format based on image contents.  This is the default if
               the filename is not recognized, and when writing to stdout.

       -o filename, --output filename
               Write the converted picture to filename instead of to standard output.

       -O x,y, --offset x,y
               Offset the converted part of the image from the top-left corner of the XCF canvas.
               Usually used with -S.

       -S wxh, --size wxh
               Crop the converted image to width w and height h.

       -T, --truecolor
               Use  standard RGB compositing for flattening indexed layers.  Without this option,
               xcf2pnm will mimic the Gimp's current strategy of rounding  each  alpha  value  to
               either full transparency or full opacity, and interpret all layer modes as Normal.

       -u, --utf8
               Use  the  raw  UTF-8 representation from the XCF file to compare and display layer
               names.  Ordinarily, layer names will be converted to  the  character  set  of  the
               current locale.

       -v, --verbose
               Print progress messages about the conversion to standard error.

       -V, --version
               Print the version numer of xcftools to standard output and exit with a return code
               of 0.

       -z, --gzip
               Equivalent to -Z zcat.  Default if the filename ends with gz.

       -Z command, --unpack command
               Specify a command that the input file is filtered through before being interpreted
               as an XCF file. The command is invoked as command filename and must produce output
               to its standard output.  Note that it is not possible to specify arguments as part
               of  command.   An uncompressor is selected automatically if the filename ends with
               gz or bz2; to suppress this, use -Z cat (which  is  implemented  without  actually
               starting a cat(1) process).

       Several groups of options are mutually incompatible; in each group the one given last will
       win:

       1)  -A and -b.

       2)  -c, -g, -m, and -n.

       3)  -D and -G.

       4)  -j, -z, and -Z.

       5)  -C and -O/-S.

LAYER SPECIFICATIONS

       If no layer name is given on the command line, all of the visible layers in the  XCF  file
       are  merged  to  produce  the  output image.  It is also possible to specify the layers to
       merge explicitly, by giving their names as separate arguments after the input filename. In
       that case, the output will contain only the named layers. The layers will be merged in the
       order they appear on the command line, with the leftmost being "at the bottom" - that  is,
       the layer ordering in the XCF file will be ignored.

       The following options can be given after a layer name to override the global properties of
       the layer:

       --mask  Enable the layer mask.

       --mode mode
               Set the layer mode (e.g., Normal or Multiply).

       --nomask
               Disable the layer mask.

       --opacity n
               Set the opacity on a scale from 0 to 255 (as used internally)

       --percent n
               Set the opacity on a scale from 0 to 100 (as in the Gimp user interface).

EXIT STATUS

       The exit status of xcf2pnm is

       0    Success

       20   Problems parsing the command line, including unknown color names  (or  missing  color
            name directory) for -b.

       21   The specified XCF file does not exist or cannot be read.

       22   A  layer named on the command line was not found, or the --mask option was used for a
            layer that has no layer mask.

       100  Transparent pixels were found, but neither -a nor -b was given.

       101  The -a option was given yet the image has no transparency.  (Use -A to go on anyway).

       102  The -G option was given, yet partial transparency was found.

       103  -g (or -m) was given, yet colored (or gray) pixels were found.

       123  The XCF file contains presumably valid features that xcftools does not support.   (As
            of  this  writing there is no known way of getting the Gimp to write an XCF file that
            will provoke this return. Please notify the author if you discover one).

       125  The XCF file is malformed.

       126  An uncompression program could not be executed, or terminated abnormally.

       127  Unexpected I/O error, internal errors, or other "this can't happen" situations.

       If an uncompression program returns an error exit  status,  this  will  be  returned  from
       xcf2pnm too.

EXAMPLES

              xcf2pnm -b white foo.xcf > foo.ppm

              xcf2pnm -a footrans.pgm -o foo.ppm foo.xcf Layer1 Layer2

       To test whether the flattened image has any transparency, use

              xcf2pnm foo.xcf > /dev/null

       To test whether the flattened image has partially transparent pixels, use

              xcf2pnm -b white -G > /dev/null

BUGS AND LIMITATIONS

       When  several  partially  transparent layers are merged, the pixel values are interpolated
       without gamma correction. (The Gimp also does it this way). Some slight rounding errors in
       the interpolation are inevitable; xcf2pnm sometimes has different rounding errors than the
       Gimp itself, especially when more than two layers are involved, or in case of some of  the
       more exotic layer modes.  These differences are usually not visible to the eye.

       Floating selections are currently not handled correctly.

       There  are probably other bugs lurking in corner cases. If you discover one, please notify
       the author.

FILES

       /etc/X11/rgb.txt

       /usr/share/X11/rgb.txt

       /usr/lib/X11/rgb.txt
               Color name database for -b.

AUTHOR

       xcf2pnm was written by Henning Makholm <henning@makholm.net>.

SEE ALSO

       xcfinfo(1), xcf2png(1)