This came from a discussion with @lbennett involving this article: http://jeffkreeftmeijer.com/2011/comparing-images-and-creating-image-diffs/ Currently we have 3 image diff modes we can use: onion skin, side-by-side and swipe. ### Proposal To add an additional blend mode to this array of diffing modes for images. ### Why? Blend mode will allow to spot smaller differences like, color differences and really small areas. ### Result would be similar to:   with UI like:  --- *@lbennett was looking into this tool for CI purposes already..* Code examples and documentation can be found in the [article](http://jeffkreeftmeijer.com/2011/comparing-images-and-creating-image-diffs/) cc: @victorwu @awhildy @jschatz1