puzzle-diff man page
puzzle-diff - Compare pictures with libpuzzle
[-b <contrast barrier for cropping] [-c] [-C <max cropping ratio>] [-e] [-E <similarity threshold>] [-h] [-H <max height>] [-l <lambdas>] [-n <noise cutoff>] [-p <p ratio>] [-t] [-W <max width>] <file 1> <file 2>
puzzle-diff compares two pictures and outputs the normalized distance.
Try puzzle-diff -h for more info.
Output distance between two images: $ puzzle-diff pic-a-0.jpg pics-a-1.jpg 0.102286
Compare two images, exit with 10 if they look the same, exit with 20 if they don't (may be useful for scripts): $ puzzle-diff -e pic-a-0.jpg pics-a-1.jpg $ echo $? 10
Compute distance, without cropping and with computing the average intensity of the whole blocks: $ puzzle-diff -p 1.0 -c pic-a-0.jpg pic-a-1.jpg 0.0523151