Influence of network delay on viewpoint change in free-viewpoint video transmission

Free viewpoint video attracts many researchers. With the video, users can change viewpoint of the video freely at the user side. Transmitting such media over IP network, the network delay deteriorates qualities of the media. In this paper, we investigate the influence of network delay in free-viewpoint video transmission by QoE (Quality of Experience) assessment. We address two transmission methods for free-viewpoint normal and stereoscopic videos. One is the synthesized image transmission method, and the other is the depth and image transmission method. Depth and image are data for synthesizing an image. We assess the image quality, the interactivity of viewpoint change, and the comprehensive quality. Assessment results demonstrate that the image quality of the synthesized image transmission method is higher than that of the depth and image transmission method, which is advantageous in terms of interactivity. The results also illustrate that the free-viewpoint stereoscopic video has higher image quality than the normal one.