On the importance of motion invertibility in MCTF/DWT video coding
On the importance of motion invertibility in MCTF/DWT video coding
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论MCTF/DWT视频编码中运动可逆的重要性
DOI：
10.1109/icassp.2005.1415338
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
C. Vázquez
中科院分区：
文献类型：
--
作者：
N. Bozinovic;J. Konrad;Wei Zhao;C. Vázquez
利用提升实现的运动补偿时间滤波是一种有效和高效的时间分解工具，有助于视频压缩与现有标准的竞争。然而，正如最近所表明的，为了使基于提升的运动补偿离散小波变换真正实现沿运动轨迹的预期滤波，运动变换必须是可逆的，并且帧之间的运动合成必须是明确的。偏离这些条件导致应用次优子带分解滤波器，这进而降低了编码性能，即使预测步长能量在运动估计期间被最小化。研究了运动场可逆误差对MCTF/DWT视频编码器编码性能的影响。我们提出了两种新的运动场反演方法，并将它们与以前报道的反演技术进行了比较。我们还比较了所有反转算法的编码结果与基于固有可逆的三角网格的编码结果。我们的结果表明，通过更准确的运动场反转，可以显著提高编码性能。
Motion-compensated temporal filtering implemented using lifting is an effective and efficient temporal decomposition tool that facilitates video compression competitive with the current standards. As recently shown, however, in order that a lifting-based motion-compensated discrete wavelet transform indeed implements the intended filtering along motion trajectories, motion transformation must be invertible and motion composition between frames must be well-defined. A departure from these conditions results in the application of sub-optimal subband decomposition filters which, in turn, degrades coding performance, even if prediction-step energy is minimized during motion estimation. We study the impact of motion field invertibility error on the coding performance of an MCTF/DWT video coder. We propose two new motion field inversion methods and compare them to previously reported inversion techniques. We also compare coding results for all inversion algorithms with those of coding based on triangular meshes that are inherently invertible. Our results show that a significant improvement in coding performance is possible with more accurate motion field inversion.