[math-fun] Fast image matching

Given two images, each consisting of N pixels. We want to find the way to rotate, scale, and translate image #1 so it best matches up with image #2. I believe I have invented algorithmic ways to do this in O(NlogN) time. I'm somewhat surprised nobody ever thought of them before. But maybe that is because somebody DID think of them before... QUESTION: did they? (It also might be because I'm wrong... I'll describe my methods later...)