Segmental downsampling intra coding based on spatial locality for HEVC
Segmental downsampling intra coding based on spatial locality for HEVC
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DOI：
10.1109/icce-berlin.2015.7391211
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发表时间：
2015-09
期刊：
影响因子：
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通讯作者：
Wen Shi;Xiantao Jiang;Tian Song;T. Shimamoto
中科院分区：
文献类型：
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作者：
Wen Shi;Xiantao Jiang;Tian Song;T. Shimamoto
作为新一代视频编码标准，高效视频编码（High Efficiency Video Coding，HEVC）与H.264/AVC相比，在相同的图像质量下，具有更好的压缩性能。基于四叉树的灵活编码单元结构定义了高达64×64的预测单元大小。大量的帧内预测模式，以实现更好的编码效率。然而，这些带来了大量的计算，并且在高分辨率视频中可能表现得不够好。本文提出了一种分段下采样帧内编码方案，该方案包括补充帧内预测模式、下采样重构参考样本和优化的帧内编码过程。所提出的补充帧内预测模式利用更接近的空间局部性参考样本，这导致更高的压缩效率。优化帧内编码过程，降低了计算复杂度，抑制了编码时间的增长。从实验结果来看，与HEVC相比，编码效率平均提高了18.43%，而编码时间仅增加了8.37%。
The new generation standard of video coding, High Efficiency Video Coding (HEVC) achieves better compression performance at the same image quality compared with H.264/AVC. Quad-tree based flexible coding unit structure defines the prediction unit sizes up to 64×64. Plenty of intra prediction modes are employed to achieve better coding efficiency. However, these bring massive calculation and may not perform well enough in high resolution video. This paper proposes a segmental downsampling intra coding scheme which consists of supplemental intra prediction modes, reconstructing reference samples with downsampling and the optimized intra coding process. The proposed supplemental intra prediction modes utilize closer spatial locality reference samples which leads to higher compression efficiency. Optimizing intra coding process reduces the computation complexity and restrains the growth in encoding time. From experimental results, coding efficiency increasing is 18.43% on an average, with only 8.37% encoding time increasing, compared with HEVC.