Simpler, perhaps, is to print the two images (or documents, or whatever), each one on a separate piece of paper. Put the two pieces of paper on top of each othe

Simpler, perhaps, is to print the two images (or documents, or whatever), each one on a separate piece of paper. Put the two pieces of paper on top of each other, hold them up to the or a bright light, and look at them. The differences should be easily discernable. A colleague of mine used to do this, great little hack.