Comment by ImageXav
3 years ago
Maybe someone here will know of a website that describes each step of the jpeg xl format in detail? Unlike for traditional jpeg, I have found it hard to find a document providing clear instructions on the relevant steps, which is a shame as there are clearly tons of interesting innovations that have been compiled together to make this happen, and I'm sure the individual components are useful in their own right!
https://github.com/libjxl/libjxl/blob/main/doc/format_overvi... is a pretty detailed but good overview. The highlights are variable size DCT (up to 128x128), ANS entropy prediction, and chroma from luminance prediction. https://github.com/libjxl/libjxl/blob/main/doc/encode_effort... also gives a good breakdown of features by effort level.
Thank you for sharing. This gives me a good idea of where to start looking.