基于HEVC的帧内模式快速判决算法

Fast Intra Prediction Mode Judgment Algorithm Based on HEVC

提出了一种HEVC帧内预测优化快速算法。算法在统计总结出当前CU层与其上层CU帧内预测模式、CBF与TU分割深度、相邻CU层之间的色度帧内预测模式之间相关性的基础上,有效地减少了帧内模式的预测,降低了帧内编码计算复杂度。同时,根据不同代价函数之间,以及色度与亮度帧内预测模式之间的相关性,分别在亮度和色度帧内预测过程中添加了RMD中cost代价最小的预测模式和最佳亮度预测模式,保证了较低的编码码率和较高的编码图像质量。实验结果表明,该算法针对各类型、分辨率的视频,在码率和PSNR基本不变的情况下,帧内编码时间平均减少38.2%。

A fast optimized algorithm for intra-frame prediction in HEVC is proposed. In this algorithm, the computational complexity of intra-frame coding is reduced because the number of calculated modes for intra-frame prediction has effectively reduced based on the statistics of the correlations between the current CU layer and its upper CU in intra-frame prediction modes, CBF and the split depths of TU, and intra-frame prediction modes in chrominance. At the same time, in order to ensure lower encoding bitrate and higher quality, the prediction mode which has the minimum cost in RMD and the best luminance prediction mode are added into the procedure of luminance intra-frame prediction and chrominance intra-frame prediction, respectively. The experimental results show that, the time for intra-frame prediction has reduced by an average of 38.2% for the videos in different types and different resolutions, while keep the bitrate and PSNR essentially unchanged.