A new fractal zerotree coding for wavelet image

Based on the mechanisms underlying the performance of fractal and DWT, one method using fractal-based selfquantization coding approach to code different subband coefficients of DWT is presented. Within this method finer coefficients are fractal encoded according to the successive coarser ones. Self-similarities inherent between parent and their children at the same spatial location of the adjacent scales of similar orientation are exploited to predict variation of information across wavelet scales. On the other hand, with respect to the HVS model, we assign different error thresholds to different scales and different shape of range blocks to different orientations of the same scale, by which the perceptually lossless high compression ratio can be achieved and the matching processing can be quickened dramatically