基于H·264的复杂度可分级的DCT算法  

Complexity Scalable Algorithm for DCT in H.264

作　　者：张冬明[1] 林守勋[1] 沈燕飞[1] 张勇东[1] 

机构地区：[1]中国科学院计算技术研究所网络与普适计算研究部

出　　处：《计算机辅助设计与图形学学报》2006年第8期1250-1256,共7页Journal of Computer-Aided Design & Computer Graphics

基　　金：国家自然科学基金(60302028;60473002);北京市自然科学基金重点项目(4051004);北京市科技计划项目(Z0004024040231)

摘　　要：改进了一种DCT快速算法,使之可用于降低H.264中整数4×4 DCT的复杂度.考虑到Laplacian模型不能准确地描述实际的H.264 DCT系数的分布,定义了3类简化块,并用统计分析的方法分别建立了这3类块的系数分布模型,进而提出了一种基于新模型的快速DCT算法.设计了简化块的蝶形算法,并分析、比较了所提出的2种快速DCT算法的复杂度.以后者为基础,设计了一种DCT复杂度可分级机制,以调节不同计算能力平台上的4×4DCT的复杂度.实验结果表明,该算法能够准确地按照设定目标控制DCT复杂度,且保证编码性能.An improved fast DCT algorithm is set up to reduce the complexity of H.264 integer 4 × 4 DCT. Since the 4 × 4 DCT distribution does not fit Laplacian model well, three simplified blocks are defined and accordingly three coefficient models are created based on a statistical analysis. Furthermore, a fast DCT algorithm based on new models is proposed. Three butterfly algorithms are designed for those 3 simplified blocks respectively, and the complexities of the proposed algorithms are analyzed and compared. Then, a complexity scalable algorithm based on the latter is presented to adjust the 4 ×4 DCT complexity on different platforms with limited computation resource. Simulation results show that the algorithm can control H. 264 4 ×4 DCT complexity within the target with negligible loss of encoding performance.

关 键 词：H.264编码 整数DCT 快速DCT算法 复杂度可分级算法 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]