sgitopnm - convert a SGI image file to a portable anymap
sgitopnm [-verbose] [-channel c] [SGIfile]
Reads an SGI image file as input. Produces a PGM image for a 2-dimensional (1 channel) input file, and a PPM image for a 3-dimensional (3 or more channels) input file.
Alternatively, produces a PGM image of any one of the channels in the input file.
Give some information about the SGI image file.
Extract channel c of the image as a PGM image. Without this option, sgitopnm extracts the first 3 channels as a PPM image or, if the input has only 1 channel, extracts that as a PGM image, and if the input has 2 channels, fails.
SGI Image File Format documentation (draft v0.95) by Paul Haeberli (email@example.com). Available via ftp at sgi.com:graphics/SGIIMAGESPEC.
Copyright (C) 1994 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de)