基于能流信息场景检测的码率控制策略

Rate Control Scheme Based on Scene Change Detection Using Energy Flow Information

该文首先介绍了用能流信息进行运动估计的方法，然后把该运动信息运用到场景检测中，最后分析了场景切换下MPEG-4 Q2码率控制算法失效的原因，提出了基于场景切换补偿的码率控制策略，并在场景切换时对MPEG-4 Q2算法得到的目标比特数进行修正。实验结果表明，该方法可以在保证编码缓冲器不发生上溢的前提下改善切换点及后继帧图像编码的质量。

Firstly, a method is introduced to estimate motion vectors between two pictures with energy flow information. Secondly, these motion vectors are applied to detect the scene change. Finally, from analyzing MPEG-4 Q2 rate-control algorithm with the situation of scene changes, an improved rate-control algorithm is proposed where the scene change is taken into account. In the improved algorithm, the target bit budget from MPEG-4 Q2 is modified when scene change occurs. Experimental results show that the proposed scheme can improve the picture quality at or after scene change without buffer overflow.