JPEG2000实时截断码率控制新算法 及其VLSI结构设计

提出一种实时编码实时截断的码率控制算法.它根据已分解的小波子带内码块有效位平面数来预测未分解的小波子带内码块有效位平面数,并根据编码通道数和小波/量化权系数为当前编码码块分配码率.并提出一种JPEG2000编码实时截断,两级码率控制的编码体系结构.第一级采用本文提出的算法实时截断码流和编码通道.第二级在低码率下采用JPEG2000标准的PCRD优化算法搜索精确的分层截断点.在最优分层截断之前多数码流和编码通道被预先截断,存储器损耗小,实时性高.低码率下,图像质量跟JPEG2000标准一致.

New Rate Control Algorithm Truncating Real Time for JPEG2000 and Its VLSI Architecture Design

A new algorithm for JPEG2000 rate control is proposed.Code streams truncation can be fulfilled adaptively in code-block coding.The number of significant bit-planes for the code blocks in the un-analyzed subbands can be predicted using those in the analyzed subbands.Our rate control scheme could allocate the rate for the current code block based on the number of coding passes and the weights of wavelet/quantification.And the VLSI architecture including two steps rate control for JPEG2000 was proposed.Firstly the coding procession is interrupted real time through our scheme.And then code streams are truncated using PCRD optimum algorithm at a low bit-rate.The most code streams and code passes are truncated before searching the optimum truncation points,thus lead to less working memory and higher speed.At low bit-rates,the image quality using our architecture is the same as that using the method JPEG2000 provided.