T. Sikora et B. Makai, SHAPE-ADAPTIVE DCT FOR GENERIC CODING OF VIDEO, IEEE transactions on circuits and systems for video technology, 5(1), 1995, pp. 59-62
In this paper, 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 alg
orithm is based on predefined orthogonal sets of DCT basis functions a
nd does not require more computations than a normal block DCT. It is s
hown that the shape-adaptive DCT algorithm can be easily incorporated
into existing block-based JPEG, H.261, or MPEG coding schemes. Thus se
gment or object based coding of images and video can be provided with
backward compatibility to existing coding standards. As an important f
eature, with the proposed technique additional content based functiona
lities currently discussed in the MPEG-4 standardization phase can be
readily achieved.