低码率小波图像编码中的分析/合成技术

针对在低码率小波图像编码中，不合适的分析／合成子系统会造成显著重构失真的问题，研究了分析／合成子系统对图像编码的影响，给出了在不同ＦＩＲＱＭＦ（对称镜像滤波器）下分析／合成子系统中有限长度信号的优化延拓方法及对应的滤波器位移要求，优化了分析／合成子系统的性能

Analysis/Synthesis Techniques for Wavelet Image Coding with Low Bit Rate

The impacts of analysis/synthesis subsystem on the performance of image coder is discussed. The optimal extension of finite length input signal for conventional FIR QMF is presented which improves the quality of wavelet image coders. To avoid the expansive length or artificial distortion introduced by periodical extension, the symmetric extension is introduced. The effects of the symmetric characteristics of odd length and even length filter, and the extension way of odd length and even length signal are studied on the analysis/synthesis subsystem in spatial and frequency domain. The non expansive and perfect reconstruction of the subsystem is implemented, and the requirement for sampling and filter shifting presented.