基于分形和小波变换的自适应混合图像编码

待编码图像经过金字塔型离散小波变换后的系数在小波域内可以组成分层树状数据结构一个小波树，这些跨越不同分辨率的小波树之间存在一定的相似性，可以通过分形变换来描述，本文正是构造小波树的基础邮基于分形和小波变换的自适应混合图像压缩算法，实验证明，我们提出的图像压缩方法与ＪＰＥＧ相比，能够在相近的压缩比的情况下（６０：１～７０：１）使得重建图像的ＰＳＮＲ（〉２９．５ｄＢ）增加约５．４ｄＢ并且图像的主观视觉

基于分形和小波变换的自适应混合图像编码

Pyramidal wavelet decomposition provides a hierarchical data structure for image representation-wavelet subtree, which is composed of the coefficients at different resolution and different orientation but with same spatial location. In this paper, the conventional fractal coding in spatial domain is extended to wavelet domain by employing the self-similarities between different wavelet subtrees through proper affine transformation. Further, in order to achieve a good trade-off between image quality and compression ratio.an adaptive partition algorithm is given which can split the wavelet subtree into children subtrees according to local image complexity. Experimental results show that the new hybrid image compression algorithm can obtain much better coding performance in terms of PSNR and subjective quality as compared to JPEG at roughly the same compression ratio.