Comment by Dwedit
5 hours ago
When I mentioned "perfectly reversible", I meant the FFT itself. You run the FFT. You run the inverse FFT. Because the FFT was quantized to 0-255, you end up with a lot of stuff that doesn't belong in the image.
5 hours ago
When I mentioned "perfectly reversible", I meant the FFT itself. You run the FFT. You run the inverse FFT. Because the FFT was quantized to 0-255, you end up with a lot of stuff that doesn't belong in the image.
Gotcha, that’s true. There’s gradations of non-reversible. FFT in practice is still not perfectly reversible, even if you use floats and don’t quantize to 8-bit. Anyway, yeah, dither will be even more non-reversible, but given how good today’s denoisers are, I bet de-dither could be pretty good if it was attacked with the same level of rigor as denoise has been.