This program is part of Netpbm.
xpbtoppm reads an X11 pixmap (XPM version 1 or 3) as input and produces a PPM image as output.
If you specify - as the filename, xpmtoppm writes the alpha output to Standard Output and discards the image.
See pamcomp for one way to use the alpha output file.
xpmtoppm can't handle a line longer than 8K characters in the the XPM input. If an input line exceeds this limit, xpmtoppm quits with an error message to that effect. Before Netpbm 10.30 (October 2005), the limit was 2K.
xpmtoppm recognizes only a limited set of the features of XPM Version 3; i.e. it rejects as invalid many valid XPM images.
The only place a comment block is valid is starting in Column 1 of the line immediately after "static char ...".
In addition, ppmtoxpm properly recognizes any single-line comment that begins in Column 1 in the color table part of the file.
There must be for every pixel a default colorname for a color type visual.
Before Netpbm 10.58 (March 2012), zero bytes per pixel causes the program to fail with a message about premature EOF on input.
Copyright (C) 1991 by Jef Poskanzer.
Upgraded to work with XPM version 3 by Arnaud Le Hors<email@example.com>, Tue Apr 9 1991.