H.264帧内预测模式快速判定算法研究

帧内预测作为H.264中提高编码效率的重要部分,其采用了率失真优化技术（RDO）进行预测模式的选择,但同时编码复杂度和计算量也明显增加.为此,提出一种快速判定算法.该算法利用区域图像的质心坐标对区域图像的平坦性和方向性进行判断,算法通过判断宏块的平坦性提前选定块大小,根据4×4块的纹理方向,确定预测模式集,降低算法复杂度.实验结果表明,与H.264标准参考编解码器JM8.6相比,所提算法编码时间节省50％以上,峰值信噪比和码率变化不大.

Fast decision algorithm for intra prediction mode in H.264

The intra prediction acts as H.264 in the important part of improve the coding efficiency.The rate-distortion optimization （RDO） technology is adopted to predict patterns of choice,but at the same time coding complexity and computation are also increased significantly.So,this paper proposes a fast decision algorithm.The algorithm using the area of image mass center coordinates of regional image flatness and direction judgment,algorithm by judging flatness of the selected block size in advance,according to the texture direction of 4 × 4 blocks,determines the prediction mode set,reduces the algorithm complexity.The experimental results show that with the H.264 codec standard reference,compared to JM8.6 the proposed algorithm coding time saved over 50%,the peak signal to noise ratio and bit rate changed little.