Compare images

A script that compare images.

This script load two images files and create:

• a layer "ref" with the first image
• a layer "out" with the second image
• a layer "col-diff" containing white pixels where colors are different between the two images
• a layer "alpha-diff" containing white pixels where alpha is different between the two images
• a layer "diff" containing white pixel when either colors or alpha are different
• an optional layer "grown-diff" where the white regions in "diff" layer have grown by a given amount of pixels

Edit 2011-12-04: I have modified the script so that it runs in gimp 2.7 without any warning about deprecated functions. I have also attached two input files that can be used to test the script diff_pictures_tests_ref.png and diff_pictures_tests_out.png. The expected output with grow=0 is diff_pictures_tests_result_grow0.png and with grow=1 diff_pictures_tests_result_grow1.png.

Edit 2011-12-05: I have modified the script so that user setting such as background color or select by color parameters are no more modified by the execution of the script. The gimp context push and pop calls were missing.