提出一种基于感知的快速自适应环路滤波算法,利用最小可察觉失真模型和Canny算子将最大编码单元进行分类,对不同分类区域进行自适应环路滤波(adaptive loop filter,ALF)的性能评估和分析,在此基础上跳过所有非敏感平滑区域和敏感平滑区域耗时的ALF处理.实验结果表明,该算法能在视频主观质量和客观质量基本不变的前提下大大降低ALF编码复杂度,有效改善ALF性能.与现有高效ALF算法相比,该算法可在编码复杂度相当的情况下获得更好的主观视频质量.
This work proposes a perceptually fast adaptive loop filter algorithm to reduce coding complexity. The largest coding units(LCUs) are classified into different regions according to the just noticeable distortion(JND) profile and using a Canny operator. Based on the ALF performance assessment and an analysis of different regions, all ALF processes for LCUs in sensitive smooth regions and non-sensitive smooth regions are skipped. Experimental results show that the proposed method can significantly reduce ALF encoding complexity while maintaining video quality. The proposed algorithm can achieve better subjective video quality with similar coding complexity compared with the existing efficient ALF algorithm.