spottopgm - convert SPOT satellite images to a PGM image
spottopgm [-1|-2|-3] [Firstcol Firstline Lastcol Lastline] inputfile
This program is part of Netpbm(1).
spottopgm converts the named inputfile to PGM format, defaulting to the first color and the whole SPOT image unless you specify otherwise with the options.
spottopgm doesn't determine the length of the input file; this would involve two passes over the input file. It defaults to 3000 lines instead.
spottopgm could extract a three-color image (as a PPM), but I didn't feel like making the program more complicated than it is now. Besides, there is no one-to-one correspondence between red, green, blue and infrared, visible and ultraviolet.
I've had only a limited number of SPOT images to play with, and therefore wouldn't guarantee that this will work on any other images.
Warren Toomey firstname.lastname@example.org