纯二维全相位滤波器组及其在图像压缩中的应用

True 2-D All Phase Filter Bank and its Application for Image Compression

摘要:

基于全相位理论,设计了3种纯二维全相位滤波器组(ADFB).这些滤波器组可以直接对图像进行纯二维分解和重构,若忽略滤波器的有限精度问题,系统是全重建的.为了减小运算量,纯二维ADFB采用提升格式实现.仿真试验表明,纯二维ADFB具有良好的数据压缩特性.在压缩率相同的情况下,尤其是IDCT-AFB7.7比Daubechies9/7小波重建图像的峰值信噪比(PSNR)最多小0.7 dB,这与采用的适合于可分离二维小波变换的四叉树SPIHT编码方案有关,若采用二叉树SPIHT编码,会使压缩效果得到改善.

Abstract:

Based on all phase theory,this paper designed three kinds of true 2-D all phase filter bank(APFB),which can be used to decompose and recompose image data in true 2-D directly.If ignoring finite precision of filters,the true 2-D APFBs have perfect reconstructioin property.To reduce computation,they are implemented in lifting scheme.Simulation has shown that true 2-D APFBs have nicer data compression property.With the same compression rate,the PSNR of reconstruction image of IDCT-AFB7.7 is at most less 0.7 dB than which of Daubechies9/7 wavelet.This is because quadtree SPIHT wavelet coding used in this paper is fit for two dimension separable wavelets.Compression effects will be improved if binary tree SPIHT wavelet coding is adopted.