[math-fun] Image understanding

Is there something like "elementary introduction to FFT's for digital photography" ? I'm trying to develop (!) some heuristics for automatically processing my digital photos, and I'm doing FFT's on them to try get a sense the orientation. Few of my photos are of fences or zebras, so I need some experience in understanding how to interpet FFTs of general scenes. Hilarie Wears Full Bark Jacket for tree hugging Help Stomp Out Box Elder Beetles