Abstract
This paper discusses effectiveness of variable shape partitioning method in fractal image coding. The quad-tree partitioning method was so far used as image partitioning of fractal image coding. In this method, we divide detail region into sub-blocks to improve quality of reconstructed image. However, since the number of range blocks increases, the rate-distortion characteristics are not necessarily improved. In the previous paper, the authors first introduced 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 show experimentally that rate-distortion characteristics of our method outperforms and the quality of reconstruction. In this paper, we make a comparison of distribution of blocks in respect of active directions and the number of range blocks to justify that our method outperforms.
