Equatorial part segmentation model for 360-deg video projection

摘要

The 360-deg or virtual reality video can capture all sides around the observer at the same time and provides the freedom to select any part of the surroundings for display using a head mounted display in the case of a single user or smart TV, curved screen, and even with video projectors placed in a 360-deg projection room in the case of multiusers. In order to encode these spherical videos with standard codecs, a projection step is necessary to transform the original 3-D space scene into a regular 2-D video sequence. Thus different geometric shapes can be used as equirectangular projection (ERP), cubemap projection (CMP), segmented sphere projection (SSP), etc. The proposed model presents the 360-deg video on eight square faces, six faces for the equatorial part, and two faces for the top and bottom views. This shape can ensure a better projection of the video thanks to the size ratio of the lateral faces, which is very close to the size ratio of televisions and video projectors used in 360-deg rooms. Quality metrics comparison shows average gains when compared with ERP and SSP models and the encoding time is hugely reduced when compared with CMP model. (C) 2019 SPIE and IS&T