pixdiff — highlight pixel colors which differ between two files
pixdiff highlights the pixels which differ between two color pix(5) format files. The input files are read pixel by pixel and if any of the color planes red, green, or blue differ, those colors are specially marked. Bytes that differ by +/-1 are drawn with intensity 192; bytes that differ more are displayed at full intensity of 255. If none of the color values differ, an NTSC converted black and white equivalent at one half the original intensity is displayed. This is to aid in seeing where in the image the different pixels lie. Upon completion, pixdiff reports the number of bytes matching, the number off by 1, and the number off by many.
Also see bwdiff(1), which can still be used on pix files, yet can produce different kinds of output.
This software is Copyright (c) 1989-2016 by the United States Government as represented by U.S. Army Research Laboratory.