Joint temporal-spatial bit allocation for video coding with dependency
Joint temporal-spatial bit allocation for video coding with dependency
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DOI：
10.1109/tcsvt.2004.839996(410)1
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发表时间：
2005-01
影响因子：
8.4
通讯作者：
Shan Liu;C.-C. Jay Kuo-C.
中科院分区：
文献类型：
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作者：
Shan Liu;C.-C. Jay Kuo-C.
本研究针对运动补偿预测与帧内插所产生的相依性，探讨时空联合位元分配问题。问题制定后，提出了几种启发式方法来提供接近最优和次优的解决方案，这个问题。首先，基于率失真（R-D）曲线的单调性，提出了一种选择性迭代算法（SIA），以获得近似最优解。然后，贪婪迭代算法（GIA）被提出作为一种次优启发式算法，以达到接近使用SIA获得的R-D性能，同时复杂度低得多。此外，通过基于绝对差微分的平均值自适应地对帧进行分组并对帧组应用贪婪修剪，次优解被显著加快，使得其可以应用于实时应用中。在编码过程中要跳过的帧和在编码帧中利用的量化参数（QP）是自适应地和联合地确定的，以达到时间和空间质量之间的适当折衷。实验结果表明，与使用固定帧率和QP的H.263+/TMN 8相比，本文提出的方法可以在不同码率下提高压缩视频的整体质量，同时还可以提高自适应量化方案的性能。
The joint temporal-spatial bit allocation problem with consideration of dependency arising from motion compensated prediction as well as frame interpolation is investigated in this research. After the problem formulation, several heuristic methods are proposed to provide near-optimal and suboptimal solutions to this problem. First, the selective iteration algorithm (SIA) based on the monotonic property of the rate-distortion (R-D) curve is proposed to achieve the near-optimal solution. Then, the greedy iteration algorithm (GIA) is presented as a suboptimal heuristic to reach an R-D performance close to that obtained using SIA, while at a much lower complexity. Furthermore, by adaptively grouping frames based on the mean of the absolute difference differentials and applying greedy pruning to groups of frames, the suboptimal solution is significantly expedited so that it can be applied in real-time applications. Frames to be skipped in the coding process and quantization parameters (QPs) exploited in coded frames are adaptively and jointly determined to reach a proper tradeoff between temporal and spatial qualities. Experimental results show that the proposed methods can enhance the overall quality of compressed video at various bit rates in comparison with H.263+/TMN8 using fixed frame rates and QPs, as well as the adaptive quantization solution proposed in.