Ubuntu Manpage: ppmtoxpm - convert a portable pixmap into an X11 pixmap

NAME

       ppmtoxpm - convert a portable pixmap into an X11 pixmap

SYNOPSIS

       ppmtoxpm [-name=xpmname] [-rgb=rgb-textfile] [-alphamask=pgmfile] [ppmfile]

       Minimum unique abbrevations are acceptable.

DESCRIPTION

       Reads  a portable pixmap as input.  Produces X11 pixmap (version 3) as output which can be
       loaded directly by the XPM library.

       For example, to convert the file "dot" (found in /usr/include/X11/bitmaps),  from  xbm  to
       xpm one could specify

              xbmtopbm dot | ppmtoxpm -name dot

       or, with a rgb text file (in the local directory)

              xbmtopbm dot | ppmtoxpm -name dot -rgb rgb.txt

OPTIONS

-name=xpmname
The -name option allows you to specify the prefix string which is printed in the
resulting XPM output. If not specified, will default to the filename (without
extension) of the <ppmfile> argument. If you do not specify -name or ppmfile,
(i.e. your input is from Standad Input), the prefix string defaults to the string
noname.

rgb=rgb-textfile
The -rgb option allows you to specify an X11 rgb text file for the lookup of color
name mnemonics. This rgb text file is typically the /usr/lib/X11/rgb.txt of the
MIT X11 distribution, but any file using the same format may be used. When
specified and a RGB value from the ppm input matches a RGB value from the <rgb-
textfile>, then the corresponding color name mnemonic is printed in the XPM's
colormap. If you don't specify -rgb or if the RGB values don't match, then
ppmtoxpm produces the color specifications in the #RGB, #RRGGBB, #RRRGGGBBB, or
#RRRRGGGGBBBB hexadecimal format.

-alphamask=pgmfile
This option names a PGM file to use as an alpha (transparency) mask. The file must
contain an image the same dimensions as the input image. ppmtoxpm marks as
transparent any pixel whose position in the alpha mask image is at most half white.

If you don't specify -alphamask, ppmtoxpm makes all pixels in the output opaque.

ppmcolormask is one way to generate an alpha mask file. You might also generate it
by extracting transparency information from an XPM file with the -alphaout option
to xpmtoppm. There are similar options on other Netpbm converters that convert
from formats that include transparency information too.

LIMITATIONS

       An  option  to match the closest (rather than exact) color name mnemonic from the rgb text
       would be a desirable enhancement.

       Truncation of the least significant bits of a RGB value may  result  in  nonexact  matches
       when performing color name mnemonic lookups.

AUTHOR