Shape-adaptive DCT for generic coding of video

A low complexity shape-adaptive DCT algorithm suitable for coding pels in arbitrarily shaped image segments is introduced. In contrast to other techniques described in literature the proposed algorithm is based on predefined orthogonal sets of DCT basis functions and does not require more computations than a normal block DCT. It is shown that the shape-adaptive DCT algorithm can be easily incorporated into existing block-based JPEG, H.261, or MPEG coding schemes. Thus segment or object based coding of images and video can be provided with backward compatibility to existing coding standards. As an important feature, with the proposed technique additional content based functionalities currently discussed in the MPEG-4 standardization phase can be readily achieved