UMRT based Adaptive Block Size Transform Coder for Images Using Quad-tree partitioning

Variable block size (VBS) transform coding techniques have 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, a new criterion for quad-tree partitioning of images based on UMRT and a new UMRT based adaptive block size transform coder are proposed. The new criterion determines the block size suitable for coding a particular area of an image. The purpose of the algorithm is to take advantage of large uniform regions that can be coded as a single large unit instead of smaller units and to use smaller units to code fine details. It is shown that the variable block size UMRT based transform coding system using the proposed UMRT based decision criterion offers better performance for all images tested.