Virtual-view-assisted video super-resolution and enhancement

A 3-D multiview video gives users an experience that is different from that provided by a traditional video; however, it puts a huge burden on limited bandwidth resources. Mixed-resolution video in a multiview system can alleviate this problem by using different video resolutions for different views. However, to reduce visual uncomfortableness and to make this video format more suitable for free-viewpoint television, the low-resolution (LR) views need to be super-resolved to the target full resolution. In this paper, we propose a virtual-view-assisted super-resolution algorithm, where the inter-view similarity is used to determine whether the missing pixels in the super-resolved frame need to be filled by virtual-view pixels or by spatial interpolated pixels. The decision mechanism is steered by the texture characteristics of the neighbors of each missing pixel. Furthermore, the inter-view similarity is used, on the one hand, to enhance the quality of the virtual-view-copied pixels by compensating the luminance difference between different views and, on the other hand, to enhance the original LR pixels in the super-resolved frame by reducing their compression distortion. Thus, the proposed method can recover the details in regions with edges while maintaining good quality at smooth areas by properly exploiting the high-quality virtual-view pixels and the directional correlation of pixels. The experimental results demonstrate the effectiveness of the proposed approach with a peak signal-to-noise ratio gain of up to 3.85 dB.