An Improved Compression Method Based on Fractal

The speed of basic fractal encoding is slow.Most of the accelerated algorithm will decrease the decoding image quality.To improve this condition,a novel algorithm is given.First,choosing an accelerated fractal encoding algorithm and the algorithm can get higher compression ration than the basic algorithm,encode the origininal image and get basic code.A residual image will be obtained by calculating between the original image and the decoding image of the basic code.The algorithm divide the residual image into 8×4 block, qualitify it by factor 12,encode the qualitify image,get the additional code. Then the additional code and the basic code constitute the image compression code.The algorithm can speed up the encoding,at the same time,it can adjust the PSNR and the compression ration easily by threshold T,so,it can expand the applied situation.