基于低比特率应用的快速运动搜索算法

在H.264编码器中,最耗时的部分就是可变块的运动估计模块.为了减少运动估计的复杂度,文中提出了一种快速运动搜索算法.该算法通过分析低比特率应用中视频图像的特征,根据当前参考帧、当前宏块分割模式以及预测残差值的比较,动态地采用相应的搜索策略以及一种有效的终止搜索算法,并且提高了预测的准确性.模拟实验表明,提出的算法在保证视频质量的同时,其搜索速度有成倍的提高,对背景变化少的运动图像的改善尤为显著.

A Fast Search Algorithm of Motion Estimation Based on Low Bit-Rate

In an H.264 encoder,the most time-consuming component is variable block-size motion estimation.To reduce the complexity of motion estimation,a fast search algorithm is proposed in this paper.By analyzing the characteristics of video sequence and considering the condition of current reference frame,macroblock's segmentation mode,and the comparison of predictive the sum of absolute difference,the algorithm uses dynamically the corresponding search pattern and the effective termination search algorithm,and then improve the veracity of prediction.The results show that the proposed algorithm can get almost the same image quality but its search speed has improved several times.