JVET-D0072 AHG8: Area Weighted Spherical PSNR for 360 video qual ity evaluation [B. Vishwanath, Y. He, Y. Ye (InterDigital)]
At the 3rd JVET meeting, AHG8 on 360 video test conditions was established. One of AHG8’s mandates is to “discuss definition of common test conditions, test sequence formats, and evaluation criteria.” In terms of quality evaluation for 360 video content, it is generally agreed that the conventional PSNR metric is not a suitable quality metric. Spherical PSNR (SPSNR) and WS-PSNR (uniform Weighted SPNSR) have been previously proposed as more suitable quality metrics for 360 video quality evaluation. In this document, we propose Area Weighted Spherical PSNR (AW-SPSNR). Based on similar concept as WS-PSNR in MPEG document m38551, AW-SPSNR reportedly overcomes some of the shortcomings of SPSNR, and is therefore asserted to be a more suitable metric for 360 video quality evaluation. AW-SPSNR is implemented in the PCT360 tool described in JVET-D0021, and is implemented for a variety of projection formats, including equirectangular (ERP), equal-area (EAP), cubemap (CMP), and octahedron (OHP).
A suggestion was made to render to a viewport, and calculate normal PSNR, and see how the proposed AW-PSNR for that region compares.