一种自适应运动估值视频代码转换的新方法  

A New Method of Video Transcoding Using Adaptive Motion Estimation

作　　者：李晓辉[1] 

机构地区：[1]安徽大学计算智能与信息处理教育部重点实验室

出　　处：《中国图象图形学报（A辑）》2001年第2期182-185,共4页Journal of Image and Graphics

基　　金：安徽省自然科学基金资助项目 !(990 4312 4)

摘　　要：针对窄带网络的视频信号传输问题 ,分析了传统视频代码转换帧速率转换时 ,由于运动矢量非最佳化所造成的图象质量下降的原因 ,并提出了一种基于量化误差的自适应运动矢量模型 ,从而减小了搜索域 ,使最佳化输出运动矢量能进行快速运动估值 ;同时根据灰度系统理论 ,提出了一种有效的灰度预测搜索方法 .另外 ,又根据DCT系数理论模型 ,采用自适应快速视频编码方法 ,进一步提高了编码速度 .实验结果表明 :该方法不仅改善了视频图象质量 。To the video signal transmission on narrow band networks, this paper analyzes the quality degradation that cause the non optimized motion vectors during the traditional video transcoding when the frame rate conversion. We proposed a model of adaptive motion vectors based on the sum of the differential quantization errors, thus reduced search area. It is possible to achieve fast motion estimation for near optimal outgoing motion vectors. Based on the gray system theory, an efficient gray prediction search(GPS) algorithm for block motion estimation is proposed. The GPS can determine the motion vectors of image blocks quickly and correctly. We speed up the encoding in further using a method of adaptive fast video encoding based on the theoretical model for discrete cosine transform(DCT) coefficients. We also present a fast DCT algorithm to speed up the calculation of DCT further when the quantization step size is large. The experimental result show that the proposed scheme improves the video quality, with a minimal increase in computational complexity.

关 键 词：视频代码转换 自适应运动估值 图象压缩编码 视频编码 

分 类 号：TN919.81[电子电信—通信与信息系统]