基于结构相似的H.264帧间预测改进算法

Improved Inter Prediction Based on Structural Similarity for H.264

H.264/AVC通过帧间多模式预测、率失真优化及其它新技术,大大提高了视频压缩效率.失真测度的选择对帧间预测模式及运动估计中匹配块的选择有很大影响.在H.264帧间预测过程中,失真测度选用的是当前块和候选块之间的绝对差和(SAD)及平方差和(SSD).结构相似度(SSIM)是新提出的一种图像质量评价方法,与其他评价方法相比,它更加符合人眼视觉系统(HVS)且计算量不大.文中将SSIM引入到H.264帧间预测作为失真测度,提出了基于结构相似的帧间预测方法(IPBSS).该方法是在作者前期工作积累上的进一步改进.实验结果显示,该算法可以在保持视觉质量不下降的前提下,平均节约13%的码流.

H. 264/AVC achieves higher compression efficiency by employing multiple modes inter prediction, rate-distortion（RD）optimal mechanism and other new techniques. Distortion metric plays an important role in video compression performance. Structural similarity （SSIM） is a new image quality assessment method, which is more consistent with Human Vision Systems （HVS）. This paper proposes to adopt SSIM as the distortion metric in the inter prediction cost functions, named ＂improved inter prediction method based on SSIM＂（IPBSS）. It is an improved method of the authors＇ previous work on MEBSS （Motion Estimation Method Based on Structural Similarity）. Simulation results show that the proposed IPBSS can averagely save bit rate more than 13 while maintaining almost the same video quality with QP= 10, 20 and 30. That is a better result than the authors ＇ previous work MEBSS.