Multimedia data compression is a key technology in the fields of Multimedia

Networking & Communication and Computer applications. Vast amounts of multimedia data like images

video or audio data make it necessary to store and transfer multimedia data in its compressed format. However

multimedia applications require technologies permitting us to process multimedia data as flexible as we can. The utilizing of compression makes the direct processing of multimedia data more difficult. So

compressed domain processing of multimedia data has become an interesting research field. In this paper

the basic concepts and theoretical topics are discussed at first and a processing model is given. Then

some important research directions are discussed and analyzed.