An adaptive variable block size DCT transform coding system

Variable block size (VBS) transform coding technique has been proven to be capable of enhancing performance of a fixed size transform coding system. However, the criterion of determining the block size used still remains to be devised. In this paper, an edge discriminator (ED) criterion is proposed to determine the block size suitable for a particular area of an image. Comparison has been made with Chen´s system by using mean square error (MSE) as criterion. It is shown that the variable block size DCT transform system using proposed decision criterion has better MSE performance for all bit rates tested