H．264中基于零块检测的模式选择算法

H．264是最新的国际视频标准。与其它视频编码标准相比，它在编码效率方面有强大的优势：在相同的重建图像质量下，H．264比H．263＋＋和MPEG-4的第2部分节约近50％的码率。但是，H．264中编码效率的提高是以增加巨大的运算量为前提的。本文提出了在模式选择算法中引入零块检测机制，并主动放弃对部分小系数块进行编码的新的模式选择算法。实验结果表明：该算法在保证图像主观质量不下降的前提下，可以大幅度提高H．264高码率下的编码效率，加快中低码率下的视频编码速度。

Mode Selection Based on Zero-Block Detection in H. 264

H.264 is the new international standard for video coding. It has great advantage on encoding efficiency compared with other standards: under the same reconstructed picture quality, H.264 can save about 50% bit-rate compared with those of H.263++ and MPEG-4 Part 2. But the high encoding efficiency is acquired by heavily increasing computation. A new mode selection method based on the zero-detection for H.264 is proposed in this paper. This new method will give up the encoding for some small coefficient blocks forwardly. Experimental results show that the new method improves the encoding efficiency of high bit-rate in H.264 without causing the decrease of subject picture quality, and decreases the encoding time of mid-low bit-rate in H.264.