Ahh, you're right. Thank you for spotting that. I was excited that the Hamming window seemed to work for filtering, but I never tried e.g. taking the FST of an

Ahh, you're right. Thank you for spotting that. I was excited that the Hamming window seemed to work for filtering, but I never tried e.g. taking the FST of an impulse filter, multiplying by the FST of an image, then running the result through FST again. There do seem to be some behavior differences for even vs odd numbered filters. And the "identity" filter is very strange: >>> fst2(fst2(tensor([[5**0.5,0,0,0,0]])) * fst2(tensor([[0,1,2,3,4]]))) [[0,1,2,3,4]] Interestingly, there do seem to be equivalents for shifting around the components, e.g. >>> fst2(fst2(tensor([[0, 0, 1, 0]])) * fst2(tensor([[0,1,0,0]]))) [[0,0,0,0.5]] But, you're right, the relation is much less clear than I originally thought. I'll spend more time on this to try to work out what the exact equivalencies are.