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