An improved fractal image coding based on the quadtree

Fractal image coding based on quadtree is a novel technique for still image compression. Compared with other image compression methods, fractal image coding has the advantage of higher compression ratio, higher decoding speed and decoded image having nothing to do with the resolution of image. However, it spends too much time to look for the best matching R_i block on encoding. To improve the encoding speed, we must narrow the search range and improve the search skills to ensure the best match block falls within the range. In this paper, an improved fractal image compression algorithm based on quadtree is proposed. First, we improve the construction method of search attractor by constructing directly from the big D_i, block, so it can save a lot of searching time in encoding. Second, the attractors can be self-constructed, so it is not happened that the attractor is not found in the traditional methods. Experimental result shows that the algorithm makes image coding faster and more efficiency.