On Sun, Jan 27, 2008 at 02:54:15PM +0100, Penguin Lover Erik squawked: > I need to find the difference between images (like the text-file diff > command, but for RGBA images). I tried "compare A.png A.png > difference.png". This should obviously produce some kind of blank image > because A.png and A.png are the same file, but for some weird reason the > produced difference.png has recognizable content! Is there a fix for > that bug or any other image diff program that is sane?
It seems that you do not understand how the compare function works http://www.imagemagick.org/script/compare.php The output image is the second image overlaid with a red "mask". The pixels that are tinted red in the output shows the pixels that differ from the original one. The ones that are not tinted red are unchanged. So if you compare A to A, you will get something that looks like A tinted by white. What you want is something like composite A.jpg -compose minus A.jpg Out.jpg Look at http://www.imagemagick.org/script/command-line-options.php#compose to see what composite operators you can use for doing the comparison. W -- Heineken (/hnkt/)... since the second millennium B.C., middle kingdom. ' ' Sortir en Pantoufles: up 415 days, 16:27 -- [email protected] mailing list
