摘要： 为降低高效视频编码(HEVC)帧内预测过程的计算复杂度,提出一种利用灰度直方图结合自相关函数的快速深度选择算法。统计每个最大编码单元(CU)的灰度值分布,生成其灰度直方图,利用灰度直方图的自相关函数排除不必要的深度计算。同时针对帧内预测模式的优化,给出3 个减少帧内候选模式数量的有效策略。应用梯度边缘检测进一步减少8 ×8 CU 的候选模式数量,使用模式相关以及当前CU 的纹理特征,对满足一定条件的CU
只选取2 种预测模式进行率失真优化计算。实验结果表明,与原始HM10． 1 相比,该算法平均可以节省约48% 的编码时间,同时又能保持较高的视频质量。
关键词:
高效视频编码,
帧内预测,
编码单元,
快速模式选择,
自相关,
梯度边缘检测
Abstract: In order to further reduce the great computational complexity for High Efficient Video Coding(HEVC),two
novel algorithms are proposed in this paper. It figures out the distribution of each LCU’s gray values in advance so that a gray histogram can be generated. By using the self-correlation of the gray histogram,some unnecessary depth levels can be skipped. Meanwhile,it also proposes three strategies to reduce the number of intra modes which are based on edge detection,intra modes correlation,texture features,respectively. Experimental results show that the proposed algorithm can save 48% of encoding time on average with negligible loss of coding efficiency compared with HM10． 1.
Key words:
High Efficient Video Coding (HEVC),
intra prediction,
Coding Unit ( CU),
fast mode decision,
selfcorrelation,
gradient edge detection
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