基于图像块叉迹的快速分形图像编码算法

摘要分形图像编码能够在高压缩比下高质量地重构图像，但需要较长的编码时间．因此，迫切需要各种快速编码算法以扩大其应用领域．分形编码的时间主要花费于在一个海量码本中搜索每个输入子块的最佳匹配块．针对这个问题，该文提出一种快速分形编码算法，它基于图像块的一种新特征——叉迹，能够在较小的搜索范围内完成输入子块的最佳匹配．实验显示，该算法能够大大缩短编码时间，同时实现和全搜索分形编码算法相同或更好的图像质量．

Fast Fractal Image Coding Based on Local Cross Trace

Fractal image coding can provide a high reconstructed image quality with a high compression ratio, but it suffers from long encoding time. Therefore, it is essential to develop fast encoding algorithms before it could be widely used for various applications. Most of the time to encode fractally an image is spent on finding out the best-matched block from a large domain pool to represent each of range blocks. This paper thus proposes a fast fractal encoding algorithm based on a newly-defined feature of an image block, namely cross trace, which can search out the best-matched block to an input range block with a reduced search. Experimental results demonstrate that the proposed algorithm can considerably shorten the encoding time, while achieving the same or better decoded image quality as baseline fractal algorithm with full search.