Region-based fractal image compression with quadtree segmentation

Fractal image coding is a novel technique for still image compression. A low bit rate region-based fractal image compression algorithm is proposed and several techniques are included as follows. First, we improve the performance of quadtree segmentation by an adaptive threshold. Then, a merging scheme is employed to the resulting quadtree segmentation that combines several similar blocks into a small number of regions. We also provide a quadtree-based segmented chain code to efficiently record the contours of the regions. The experimental results show that the proposed scheme has the lowest bit rate among the existing schemes at the same level of image quality.