An Improved No-search Fractal Image Coding Method

In order to improve the performance of no-search fractal coding further, a two order fitting surface is proposed to approximate the range blocks and domain blocks. In our research, a novel gray-level transform with a fitting surface is introduced. On one hand, the fitting surface we propose can approximate the range and domain blocks better than the previous fitting planes, this can lead to smaller collage errors between the range blocks and best matching domain blocks. On the other hand, since the introduced fitting surface can be also used for both the range blocks and domain blocks, many bits can be saved to improve the compression ratio. Moreover, the no-search and quadtree techniques are also adopted, so the proposed method can be completed in a short time. Experiments show that compared with the previous similar method, the proposed method can provide higher PSNR with the same Bpp, higher PSNR while maintaining the same encoding time.