HEVC帧内模式决策和CU划分快速算法

发布时间：2018-05-13 06:47

本文选题：HEVC帧内模式决策 + CU块划分　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：HEVC(High Efficiency Video Coding)是继H.264/AVC之后的新一代视频编码标准，其核心目标是在H.264/AVC High Profile的基础上，将视频压缩效率提高一倍，满足人们对高质量视频越来越强烈的需求。然而编码性能提升的同时带来了很高的计算复杂度，高计算复杂度直接影响了编码速率。因此如何在保证编码性能的前提下降低HEVC编码算法复杂度，加快编码速度，成为当前HEVC视频编码技术研究的热点问题。为了提升编码性能，本文首先研究了HEVC编码标准的关键技术，然后针对其中的帧内预测技术和编码块划分技术进行了深入的研究，HEVC采用了基于率失真代价的四叉树遍历递归编码块划分算法和高达35种预测模式的帧内预测算法，本文针对这两部分内容提出了两种快速算法，前者是基于图像特征的HEVC帧内编码块划分快速算法，算法根据视频帧图像固有的纹理复杂度特性略过或者提前终止编码块某些层次的划分过程，减少需要进行率失真代价计算的编码块数目。实验结果表明与HM12.0原始算法相比，在全I帧的情况下，该算法在视频编码质量基本不变的前提下，即BDPSNR平均减少不超过8%的前提下，平均减少了约39%的编码时间，编码速率得到了显著的提升。后者是基于预测块方向特征的帧内预测模式决策快速算法，算法对当前预测块的方向性进行判断，从而减少执行帧内预测率失真优化过程的候选模式个数。实验结果表明与HM12.0原始算法相比，在全I帧的情况下，该算法在在视频编码质量基本不变的前提下，平均减少了约18.2%的编码时间，，一定程度上提高了编码速率。
[Abstract]:HEVC(High Efficiency Video Coding) is a new generation of video coding standard after H.264/AVC. Its core goal is to double the efficiency of video compression on the basis of H.264/AVC High Profile to meet the increasing demand for high-quality video. However, the improvement of coding performance leads to high computational complexity, which directly affects the coding rate. Therefore, how to reduce the complexity of HEVC coding algorithm and speed up the coding speed while ensuring the performance of HEVC video coding has become a hot issue in the current research of HEVC video coding technology. In order to improve the coding performance, this paper first studies the key technology of HEVC coding standard. Then, the intra prediction technology and coding block partitioning technology are studied in detail. The HEVC adopts quadtree traversal recursive block partition algorithm based on rate-distortion cost and intra prediction algorithm with up to 35 prediction modes. In this paper, two fast algorithms are proposed for these two parts. The former is a fast algorithm for HEVC intra coding block partitioning based on image features. Based on the inherent texture complexity of the video frame image, the algorithm skips or terminates the partition process of some layers of coding blocks in advance, thus reducing the number of coding blocks that need to be calculated at rate-distortion cost. The experimental results show that compared with the original HM12.0 algorithm, the algorithm reduces the coding time by about 39% on the premise that the video coding quality is basically unchanged, that is, the average BDPSNR reduction is less than 8%. The coding rate has been significantly improved. The latter is a fast algorithm for intra-prediction mode decision based on the prediction block direction feature. The algorithm judges the directionality of the current prediction block and reduces the number of candidate modes for performing the intra-prediction rate-distortion optimization process. The experimental results show that compared with the original HM12.0 algorithm, the algorithm reduces the coding time by about 18.2% and improves the coding rate to some extent under the condition of full I frame.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.81

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