This is clearly something I missed during the first implementation. The
specification is crystal clear about it: "The quantization elements
shall be specified in zig-zag scan order."
This patch fixes the weird behavior we had when using the quantization
table.
This solution is a middle ground between re-computing `cos` every time
and a much more mathematically complicated approach (as we have in the
decoder).
While still being far from optimal it already gives us a 10x
improvement, not that bad :^)
Co-authored-by: Tim Flynn <trflynn89@pm.me>
This encoder is very naive as it only output SOF0 images and uses
pre-defined Huffman tables.
There is also a small bug with quantization which make using it
over-degrade the quality.
