摘要
针对JPEG2000推荐的码率分配算法导致的计算冗余多、编码速度慢并且编码缓存大的不足,本文提出一种编码前最优分配码率的方法以提高JPEG2000的编码速度。该方法通过对小波系数失真模型的率失真理论分析,得出在总码率限制的情况下,使得总体视觉加权失真最小的最佳码率分配准则,并根据该准则给出可实现的码率分配算法。实验表明,该方法可以实现精确有效的编码前码率预分配,做到了"所编即所需",加速了JPEG2000编码,满足高速编码和低缓存需求的要求。
For the sake of accelerating the coding process of JPEG2000 and avoiding coding useless codes, a pre-coding Rate-distortion Optimized （RDO） rate allocation algorithm was proposed. At first, a formula for minimizing the total distortion in a limited rate was proved by analyzing the rate-distortion model of wavelet coefficient, and then a realizable algorithm was provided following the distortion minimum formula. The experiment results indicate that the proposed algorithm realizes accurate pre-coding rate control and minimizes distortion. Furthermore, it makes the encoder just encode the bytes that are needed, accelerates JPEG2000 encoding process and reduces the encoder＇s memory consumption.
出处
《光电工程》
CAS
CSCD
北大核心
2008年第10期81-85,共5页
Opto-Electronic Engineering
基金
863高技术项目
