基于人眼视觉特性的嵌入式小波零树编码改进①

在分析了嵌入式小波零树编码算法（EZW）的基本理论基础上，提出了一种以8个标志住代替原EZW算法中4个标志位的改进算法。改进算法中，重新定义零树的结构，降低了编、解码复杂度节省了存储的空间，且有利于提高压缩比；重新分类重要系数一方面增加了图像边缘信息编码，另一方面极大的减少了零树根的数量，提高了压缩比。仿真结果表明，改进算法重构图像质量及主观视觉效果明显好于原算法。

An Improved Image Coding Algorithm Based on EZW and HVS

This paper analyses the basic theory of the EZW algorithm, and proposes an improved EZW based on eight symbols instead of four symbols used in EZW. In this method, giving the definition of zero-tree structure anew does not only reduce the complexity of encoding and decoding, but also saves the storage space and improves compression ratio. In e-classifying the significant symbols, the edge information is considered. At the same time, the number of zero tree roots is geatly redued and compression ratio is improved. Experimentsal results show that the improved algorithm performs better than EZW in reconstructing image quality.