Abstract
This paper discusses variable shape partitioning method to improve coding performance of fractal image coding. In the quad-tree partitioning method, which is well known as one of variable shape partitioning, we divide detail region into small range blocks to improve quality of reconstructed image. However, since the number of range blocks increases, the rate-distortion characteristics are not necessarily improved. In this paper, we first introduce a partitioning method in which we control blocks such that their sides stand parallel to local directions and the number of pixels in block remains constant, and discuss the selection method to decide the fitting domain blocks. In the last, we carry out coding simulations for our and the existing methods, and show that rate-distortion characteristics of our method outperforms and the quality of reconstruction are much improved for images including many edges.
