Zhang Yun, Zhang Huan, Yu Mei, Kwong Sam, Ho Yo-Sung
IEEE Trans Image Process. 2019 Jul 29. doi: 10.1109/TIP.2019.2929433.
The temporal flicker distortion is one of the most annoying noises in synthesized virtual view videos when they are rendered by compressed multi-view video plus depth in Three Dimensional (3D) video system. To assess the synthesized view video quality and further optimize the compression techniques in 3D video system, objective video quality assessment which can accurately measure the flicker distortion is highly needed. In this paper, we propose a full reference sparse representation based video quality assessment method towards synthesized 3D videos. Firstly, a synthesized video, treated as a 3D volume data with spatial (X-Y) and temporal (T) domains, is reformed and decomposed as a number of spatially neighboring temporal layers, i.e., X-T or Y-T planes. Gradient features in temporal layers of the synthesized video and strong edges of depth maps are used as key features in detecting the location of flicker distortions. Secondly, dictionary learning and sparse representation for the temporal layers are then derived and applied to effectively represent the temporal flicker distortion. Thirdly, a rank pooling method is used to pool all the temporal layer scores and obtain the score for the flicker distortion. Finally, the temporal flicker distortion measurement is combined with the conventional spatial distortion measurement to assess the quality of synthesized 3D videos. Experimental results on synthesized video quality database demonstrate our proposed method is significantly superior to other state-of-the-art methods, especially on the view synthesis distortions induced from depth videos.
在三维（3D）视频系统中，当通过压缩多视点视频加深度来渲染合成虚拟视图视频时，时间闪烁失真是最烦人的噪声之一。为了评估合成视图视频质量并进一步优化3D视频系统中的压缩技术，非常需要能够准确测量闪烁失真的客观视频质量评估方法。在本文中，我们针对合成3D视频提出了一种基于全参考稀疏表示的视频质量评估方法。首先，将合成视频视为具有空间（X - Y）和时间（T）域的3D体数据，将其重新组织并分解为多个空间相邻的时间层，即X - T或Y - T平面。合成视频时间层中的梯度特征和深度图的强边缘被用作检测闪烁失真位置的关键特征。其次，然后推导并应用时间层的字典学习和稀疏表示，以有效地表示时间闪烁失真。第三，使用秩池化方法汇总所有时间层分数并获得闪烁失真分数。最后，将时间闪烁失真测量与传统的空间失真测量相结合，以评估合成3D视频的质量。在合成视频质量数据库上的实验结果表明，我们提出的方法明显优于其他现有方法，特别是在深度视频引起的视图合成失真方面。
