The DjVu Reference Library contains the full DjVu decoder,
the full IW44 wavelet encoder/decoder for continuous tone
images, and the back-end of JB2 bilevel image compression
technique.
However, it does not contain the code for
separating document images into foreground and background
layers, nor does it contain the code of the lossy JB2 scheme
that achieves the highest compression ratios on bitonal
images.