Bach Nguyen Gia, Tran Chanh Minh, Duc Tho Nguyen, Tan Phan Xuan, Kamioka Eiji
Graduate School of Engineering and Science, Shibaura Institute of Technology, Tokyo 135-8548, Japan.
Department of Information and Communications Engineering, Shibaura Institute of Technology, Tokyo 135-8548, Japan.
Sensors (Basel). 2022 Jun 30;22(13):4948. doi: 10.3390/s22134948.
In light field compression, graph-based coding is powerful to exploit signal redundancy along irregular shapes and obtains good energy compaction. However, apart from high time complexity to process high dimensional graphs, their graph construction method is highly sensitive to the accuracy of disparity information between viewpoints. In real-world light field or synthetic light field generated by computer software, the use of disparity information for super-rays projection might suffer from inaccuracy due to vignetting effect and large disparity between views in the two types of light fields, respectively. This paper introduces two novel projection schemes resulting in less error in disparity information, in which one projection scheme can also significantly reduce computation time for both encoder and decoder. Experimental results show projection quality of super-pixels across views can be considerably enhanced using the proposals, along with rate-distortion performance when compared against original projection scheme and HEVC-based or JPEG Pleno-based coding approaches.
在光场压缩中，基于图的编码在利用沿不规则形状的信号冗余方面很强大，并且能实现良好的能量压缩。然而，除了处理高维图的时间复杂度高之外，它们的图构建方法对视点之间视差信息的准确性高度敏感。在现实世界的光场或由计算机软件生成的合成光场中，由于渐晕效应以及两种光场中视图之间的视差较大，分别使用视差信息进行超光线投影可能会出现不准确的情况。本文介绍了两种新颖的投影方案，其视差信息误差更小，其中一种投影方案还能显著减少编码器和解码器的计算时间。实验结果表明，使用这些方案可以显著提高跨视图超像素的投影质量，以及与原始投影方案和基于高效视频编码（HEVC）或基于联合图像专家组全光（JPEG Pleno）的编码方法相比的率失真性能。
