提出了一种基于视频内容预分析的变尺寸宏块分割(CBVSBM)的实现方案,变尺寸宏块分割是H.264编码器端提供的重要编码工具。该方案根据每帧视频的内容,自适应地在自顶向下的变尺寸运动估计(TDVSBM)和自底向上的变尺寸运动估计(BUVSBM)两种变尺寸宏块分割算法(VSBM)间进行切换,从而结合了两种算法的优点。为了实现两种VSBM算法间的自适应选择,提出了一种简单而有效的基于STGS图的预判准则。理论分析和实验结果表明,该算法的运算复杂度低于TDVSBM和BUVSBM,而在视频质量上总是优于TDVSBM且与BUVSBM几乎相当。

As one of the effective coding tools in the newly-published H.264/AVC coding standard,variable-size block motion estimation is of great importance in performance evaluation of the encoder.A content-based variable-size block partition method is presented for H.264.The proposed algorithm is based on pre-analysis of video content to select between TDVSBM and BUVSBM that best suits the video in unit of the frame.To enable the adaptive selection,a method based on the STGS-image is proposed to develop an efficient and computationally simple criterion.Experimental results show that the proposed content-based variable-size block motion estimation(CBVSBM) algorithm reduces the computational complexity in contrast to both TDVSBM and BUVSBM,but with similar visual quality.