摘要
Mallat算法，即基于多分辨分析的金字塔算法是小波变换的快速算法，在工程上获得了广泛的应用但是作者发现，Mallat算法存在频率混淆．本文全面深入地分析了Mallat算法存在频率混淆的原因，是由正交镜象滤波器（QMF）的频域特性、隔点采样和隔点插零造成的．进而提出了一种改进的小波分解与重建算法，即结合FFT的小波变换算法该算法完全消除了频率混淆.
Mallat algorithm, which is also called the pyramid algorithm based on multiresolution analysis, is the fast algorithm of wavelet transform. It is used widely in engineering. The authors found that There erists frequency aliasing in Mallat algorithm. Sometimes it is severe. The reasons of the frequency aliasing in Mallat algorithm are analyzed profoundiy in this paper. It is caused by the frequency charater of the quadriture mirror filters and the process of keeping one sample out of two and the process of putting one zero between each sample in Mallat algorithm. This paper presents an improved algorithm . Which is called an algcrighm based on wavelet transform and FFT. It is shown that Using this algorithm the frequency aliasing is avoided.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
1999年第2期61-64,共4页
Journal of Harbin Institute of Technology
