The page says:
The Almacom JPEG-2000 library was written in an effort to produce the cleanest and simplest implementation possible of the JPEG-2000 standard. We have put a particular emphasis on good architecture design and code simplicity, while at the same time providing an implementation as complete and efficient as possible.

DataCompression.info user Luca M. said I was looking for a good library of wavelets. Now I’ve found it !