Projection Methods for 360-degree Video

Abstract

This paper discusses the methods used for projecting 360-degree video onto a two-dimensional plane to reduce the transmission bandwidth. The two primary methods examined are Equirectangular Projection and Cube Projection. Equirectangular Projection is known for its oversampling problem at high latitudes, leading to uneven pixel distribution. To address this, a region adaptive smoothing technology is introduced to optimize video quality and save bandwidth. Cube Projection, which maps spherical video onto the faces of a cube, is analyzed for its ability to maintain pixel uniformity and reduce geometric distortion. The paper further discusses the solutions for correcting motion compensation errors in Cube Projection, emphasizing the importance of multi-facet and cube face extensions in eliminating geometric distortions.