It extracts the already quantized DCT coefficients and related data from the JPEG bitstream and re-encodes them with JPEG XL’s more efficient entropy coding and container,
Think of it as zip compression that is specially designed for JPEG and putting the JPEG data in a different/better container.
It extracts the already quantized DCT coefficients and related data from the JPEG bitstream and re-encodes them with JPEG XL’s more efficient entropy coding and container,
Think of it as zip compression that is specially designed for JPEG and putting the JPEG data in a different/better container.