【摘要】 将运动矢量估计与三维小波变换相结合用于视频信号压缩 .这种方法在对序列作时域上的一维变换时 ,是对各帧中由运动矢量联系起来的一条运动轨迹上的像素进行 .由于在实际情况中 ,通过运动矢量联系而形成的像素运动轨迹是任意长度的 ,这就需要对任意长度的像素串作一维小波变换 .此文在二代小波提升算法基础上 ,通过修改边界延拓方法获得一种任意长度信号的小波变换算法 ,并将其用于基于运动轨迹的视频时域小波变换 .实验结果表明 ,对于运动幅度大的视频序列 ,这种方法可以获得比常规三维小波变换编码高的压缩性能 .更多还原

【Abstract】 Motion estimation is combined with 3-D wavelet transform for video coding. In classical 3-D wavelet transform for video, the time domain wavelet transform is performed on pixels in the same spatial coordinate of each frame. But in this paper wavelet transform is performed on pixels in one motion trajectory which is constructed by motion vectors in order to fully utilize the redundancy in the time domain. Because the length of motion trajectory is arbitrary, a new wavelet transform method for arbitrary length signals is needed. A length-adaptive wavelet transform algorithm based on modifying boundary extension method of the lifting scheme is used. The experimental result shows that for video sequence with wide range of movement the compression performance of this approach is better than approach using classical 3-D wavelet transform.更多还原