Second-order derivative-based smoothness measure for error concealment in DCT-based codecs
Second-order derivative-based smoothness measure for error concealment in DCT-based codecs
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DOI：
10.1109/76.728413
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发表时间：
1998-10
期刊：
影响因子：
--
通讯作者：
Wenwu Zhu;Yao Wang;Qin-Fan Zhu
中科院分区：
文献类型：
--
作者：
Wenwu Zhu;Yao Wang;Qin-Fan Zhu
我们研究了使用基于离散余弦变换（DCT）的编解码器的图像和视频通信系统中丢失或错误变换系数的恢复。之前，我们已经开发了一种利用图像信号的平滑特性并通过最大化平滑度量来恢复损坏块的技术。其中，一阶导数被用作平滑度量，这可能导致尖锐边缘的模糊。为了缓解这一问题，我们提出使用二阶导数作为平滑度量。我们的仿真结果表明，二次变分和拉普拉斯算子的加权组合可以显著减少边缘上的模糊，同时增强边缘的平滑性。
We study the recovery of lost or erroneous transform coefficients in image and video communication systems employing discrete cosine transform (DCT)-based codecs. Previously, we have developed a technique that exploits the smoothness property of image signals and recovers the damaged blocks by maximizing a smoothness measure. There, the first-order derivative was used as the smoothness measure, which can lead to the blurring of sharp edges. In order to alleviate this problem, we propose to use second-order derivatives as the smoothness measure. Our simulation results show that a weighted combination of the quadratic variation and the Laplacian operator can significantly reduce the blurring across the edges while enforcing smoothness along the edges.