基于小波域的分形图像压缩

在分析产生块效应原因基础上,定义了一种度量块效应的客观方法.为了消除传统分形图像压缩中产生的块效应,提出先将原图像变换到小波域,再进行分形压缩.这种方法既继承了传统分形图像压缩的编码原理,又利用了小波变换的优良特性,从而取得了更好的压缩效果.此外,根据小波系数的能量分布特征,提出了一种加快相似匹配的方法.

Fractal Image Compression on Wavelet Domain

After analyzing the cause for generating tiling effect, an objective measure for calculating tiling effect is defined. In order to eliminate tiling effect, an original image is first transformed into wavelet domain, on which fractal compression and arithmetic coding are performed. This method inherits the principles of fractal coding and exploits the good characteristics of wavelet transform. Furthermore, similarity matching between blocks is sped up by utilizing the energy distribution among wavelet coefficients. As a result, image compression performances are improved in both PSNR and coding speed.