Capability of Fractal Image Compression with Adaptive Quardtree Partitioning

In this paper, efficiency and capability of an adaptive quardtree partitioning scheme of fractal image compression technique is discussed with respect to quardtree partitioning scheme. In adaptive quardtree partitioning scheme, the image is partitioned recursively into four sub-images. Instead of middle points of the image sides are selected as in quardtree partitioning scheme, Image contexts are used to find the partitioning points. The image is partitioned row-wise into two sub-images using biased successive differences of sum of pixel values of rows of the image. Biased successive differences of sum of pixel values of columns of the sub-images are used to partition each sub-image farther column-wise into two parts. Then, a fractal image compression technique based on the adaptive quardtree partitioning scheme is discussed. The comparison of the compression ratio, compression time and PSNR are done between fractal image compression with quardtree and adaptive quardtree partitioning schemes. The fractal image compression with adaptive quardtree partitioning scheme offers better rate of compression most of the time with comparatively improved PSNR. But, the time of compression of the same scheme is much more than its counterpart.