最佳正交小波变换信号压缩

正交小波变换由于存在下采样，信号y(n）和y(n-1）的小波变换系数有可能差异极大，这会对信号压缩的性能造成很大的影响。本文提出了最佳小波变换的概念，我们在每个变换尺度上均对偶采样和奇采样的结果进行保留，产生一个二叉树结构，由此二叉树的任意一路径均可重构原信号，我们按照一定的准则确定最优分解路线，仿真结果表明，该变换方式较标准正交小波变换在取得较高压缩能力的同时，具有更高的信噪比。

SIGNAL COMPRESSION BY BEST ORTHOGONAL WAVELET TRANSFORM

Due to the subsample, OWT (Orthogonal Wavelet Traosform) is translation-variant, which will depress the compression efficiency of OWT. Here we put forward the concept of Best OWT. In every transform scale, we hold all the results of even index subsample and odd index subsample. So a bintree structure is composed. From any route of the bintree the signal can be reconstructed. By some given criterion, we can determine the best route and call the wavelet transform along this path the Best OWT. The simulations show that the compression performance of Best OWT is always better than ordinary OWT.