I played with this stuff in high school and college. Principle Component Amalysis (PCA), as another commenter said. One small quibble, with JPEG you don’t “lo

I played with this stuff in high school and college. Principle Component Amalysis (PCA), as another commenter said. One small quibble, with JPEG you don’t “lose” the “high-frequency” data; that would blur the image. You approximate it, so you could argue you “lose” some of it. JPEG is not very good at compressing high-frequency data, which is basically the edges of things, so if your JPEG has sharp edges, you are not losing much high-frequency data, just compressing everything else.