一种提高分形图像压缩编码速度的方法

Methods improving for fractal image compression

为了提高分形图形压缩编码速度,在定义父块与子块对比自身而得到的特征值的基础上,证明了匹配父块存在的条件,并提出了改进的分形图像压缩方法.该方法使得子块只搜索那些特征值符合条件的父块,从而降低了搜索的复杂度.通过讨论父块的旋转变换,提出了一种父块经过旋转后其特征值不变的变换,这使得无效父块在搜索过程中的对比计算次数明显减少.实验表明,有特征值的搜索速度是无特征值搜索速度的3倍或4倍,而图像的压缩质量却没有受到很大的影响.

Improving coding speed was a key problem of image fractal compression.The authors used defined eigenvalues to obtain the father-block or child-block characteristics by the self-contrast.The author proved that there were conditions for the existence of the father-block need just search for eigenvalues characteristics of father-blocks;and thus reduce the searching complexity.A method is introduced whereby the father-block after circumvolution does have change in its eigenvalue, so that in the search for ineffective father-block,the number of times of comparatively rapid calculation is distinctly reduced.Experimental results show that the search for eigenvalues is 3 or 4 times faster than that for non-eigenvalues while the quality of restituted images is not influenced by the search process.