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360-degree video is an emerging form of media that encodes information about all directions surrounding a camera, offering an immersive experience to the users. Unlike traditional 2D videos, visual information in 360-degree videos can be naturally represented as pixels on a sphere. Inspired by state-of-the-art deep-learning-based 2D image super-resolution models and spherical CNNs, in this paper, we design a novel spherical super-resolution (SSR) approach for 360-degree videos. To support viewport-adaptive and bandwidth-efficient transmission/streaming of 360-degree video data and save computation, we propose the Focused Icosahedral Mesh to represent a small area on the sphere. We further construct matrices to rotate spherical content over the entire sphere to the focused mesh area, allowing us to use the focused mesh to represent any area on the sphere. Motivated by the PixelShuffle operation for 2D super-resolution, we also propose a novel VertexShuffle operation on the mesh and an improved version VertexShuffle_V2. We compare our SSR approach with state-of-the-art 2D super-resolution models and show that SSR has the potential to achieve significant benefits when applied to spherical signals.
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Saliency Computation for Virtual Cinematography in 360° Videos
Recent advances in virtual reality cameras have contributed to a phenomenal growth of 360∘∘ videos. Estimating regions likely to attract user attention is critical for efficiently streaming and rendering 360∘∘ videos. In this article, we present a simple, novel, GPU-driven pipeline for saliency computation and virtual cinematography in 360∘∘ videos using spherical harmonics (SH). We efficiently compute the 360∘∘ video saliency through the spectral residual of the SH coefficients between multiple bands at over 60FPS for 4K resolution videos. Further, our interactive computation of spherical saliency can be used for saliency-guided virtual cinematography in 360∘∘ videos.
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- Award ID(s):
- 1823321
- PAR ID:
- 10280495
- Date Published:
- Journal Name:
- IEEE computer graphics and applications
- Volume:
- 41
- Issue:
- 4
- ISSN:
- 1558-1756
- Page Range / eLocation ID:
- 99-106
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1109/MCG.2021.3080320
