3 ms·
Dropping the high frequencies does create zero runs, and even JPEG encodes zero runs as a run-length (RRRR in the spec) But DCT isn't very useful for lossless
by brigade 1y ago
Dropping the high frequencies does create zero runs, and even JPEG encodes zero runs as a run-length (RRRR in the spec)
But DCT isn't very useful for lossless since any lossless frequency domain representation requires more range than the source, and you can't quantize to counter it.
- Sesse__ 1y agoJPEG even has a special code from “the rest from here is all zeros, so we stop this block now”. The entire format is pretty much organized around trying to get as many zero coefficients as possible.