HDTV图像活动性分析在码率分配中的应用

Application of the analysis of HDTV picture motion in bit rate alloction

由于现存硬件条件的局限，高清晰度电视视频编码器的硬件实现只能通过数片ＳＤＴＶ级的编码芯片来完成，其子编码器的码率分配会影响整个编码器的图像编码质量。实验表明，平均分配码率存在着子图的码率分配与其活动性不匹配的弊病，为此提出了一种基于活动性分析的码率分配方法。在对Ｂａｓｋｅｔｂａｌｌ，Ｓｋｉ及Ｈｈｃ序列的软件模拟结果显示表明，该方法提高了图像编码质量的一致性，使得各重建子图的ＰＳＮＲ差值变小。

The HDTV video encoder can only be implemented by several SDTV video encoding chips for the rea-son of current hardware limitations. The allocation of bitrate of the SDTV encoders will affect the picture quality of the encoder.Experiments show that the method of equally allocating bitrate may cause missmatching between the activity of the sub--picture and its bitrate. An allocating method is proposed based on activity analysis.The software experimental results of Basketball,Ski and Hhc sequences show that this method will enhance the consistency of the quality of the en-coded picture, so that the difference among the PSNR's of the reconstructed sub--pictures is reduced.