Abstract: Intra-prediction is an important part of H.264. A fast algorithm for intra-prediction mode decision is presented in this paper to ensure image with less performance degradation and bit-rate increase, while reducing intra-
prediction coding time. It uses the texture direction of [4×4] block and the correlation between [4×4] block and [16×16] block to predict the intra-frame mode, which chosen by double thresholds. Experimental results show that compared with the full searching algorithm, this algorithm can decrease the coding time by 35%~40%, while PSNR drops 0.03~0.1 dB.

Key words: H.264, intra prediction, intra mode decision, Rate Distortion Optimization（RDO）

摘要： 帧内预测是H.264视频编码标准的重要组成部分。为了保证在图像质量和编码比特率大致不变的前提下，减少帧内预测模式选择的编码时间，提出了一种基于[4×4]块的纹理方向性和[4×4]块与[16×16]块之间的相关性并通过设置双阈值进行选择预测模式的快速算法。实验结果表明该算法与帧内预测编码的全搜索算法相比，编码时间节约了35%~40%，信噪比损失了0.03~0.1 dB。

关键词: H.264, 帧内预测, 模式选择, 率失真优化