基于视觉注意的宏块级码率控制算法

摘要

H.264/AVC码率控制算法中在宏块层采用平均分配目标比特数的策略，虽然有利于降低码率控制算法的复杂度，却造成重建图像并不符合人眼的主观视觉感受。本文根据视觉心理学研究成果，分析了影响视觉注意主要因素，对宏块层比特分配算法进行优化，本文算法提高了重建图像的主观视觉质量，并且有较好的码率控制精度及更稳定的客观质量，算法额外增加的计算复杂度在可接受的范围，为实时应用提供了可能。%H.264/AVC rate-control algorithms adopt equal bit-allocation strategy at MB-level, which helps to reduce the computational complexity of algorithms, but the reconstructed images do not conform to the subjective visual perception. Based on the results of the study of visual psychology, analyzing of the main factors influencing visual attention, MB-level bit allocation algorithm is optimized, the proposed algorithm can not only enhances the coding subjective quality but also increases the accuracy of rate control and the stability of objective quality. Furthermore, the additional computation complexity is acceptable, thus the proposed algorithm can be applied to real-time application.