On Sun, Jan 30, 2022 at 07:27:10AM +0100, Andreas Rheinhardt wrote:
> Writing optimal huffman tables is incompatible with using slices

Fundamentally, this should not be i think

CCITT Rec. T.81 says

"If a table specification for a
given destination occurs more than once in the compressed image data, each specification shall replace the previous
specification. The quantization table specification shall not be altered between progressive DCT scans of a given
component."

This explicitly mentions quatization tables but not huffman tables so it
seems allowed that they can be changed 

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

If you drop bombs on a foreign country and kill a hundred thousand
innocent people, expect your government to call the consequence
"unprovoked inhuman terrorist attacks" and use it to justify dropping
more bombs and killing more people. The technology changed, the idea is old.