This program is part of Netpbm.
listpmfile reads a Lisp Machine bitmap as input and produces a PGM image as output.
This is the file format written by the tv:write-bit-array-file function on TI Explorer and Symbolics lisp machines.
Multi-plane bitmaps on lisp machines are color; but the Lispm image file format does not include a color map, so we must treat it as a monochrome instead and produce PGM. This is unfortunate.
Also, the Lispm code for saving bitmaps has a bug, in that if you are writing a bitmap which is not mod32 across, the file may be up to 7 bits too short! They round down instead of up, and we don't handle this bug gracefully.
Copyright (C) 1991 by Jamie Zawinski and Jef Poskanzer.