采用块参考像素特征的快速帧内预测模式选择新算法

帧内预测是H.264采用的一种编码新技术。与以前的编码标准相比，H.264编码性能有了很大的提高，但同时编码复杂度和计算量也明显增加。该文研究了提高H.264编码速度的途径，着重分析了帧内预测模式快速选择的问题。经过分析发现，4X4亮度块的参考像素亮度值通常具有相似性，对应地，,4X4亮度块的9种预测模式所得的预测结果也是相近的。根据4X4亮度块参考像素的这一特征，该文提出了一种基于4X4亮度块参考像素特征的快速帧内预测模式选择算法。实验结果说明了该文算法的有效性，与H.264编码器JM92相比，该算法的计算量减少了46%，而编码质量、PSNR和输出码率保持基本不变。

Intra-prediction is one of the new techniques adopted by H.264. Compared with the previous video coding standards, H.264 improves coding performance greatly. However, the computation load of H.264 video coding increases drastically. This paper investigates improvement of encoding speed for H.264 with special focus on fast intra prediction mode selection. Some experimental analyses indicate that the luminance values of the reference pixels for each 4 x 4 luminanceb locka rec ommonlys imilar,an din th atca se,th ep redictionb lockso fth en inep redictionm odesa rea lsos imilar. According to this feature of 4 x 4 luminance block, a fast mode selection algorithm for intra prediction is proposed. Experimentalre sultssh owt hep roposeds chemeis v ery efective.C omparedw ithJ M92in H .264e ncoder,it re duces4 6%encoding time while maintaining the PSNR and bit rate