Polar square projection for panoramic video

Panoramic video provides an immersive experience by presenting a 360° spherical video content. Due to the limitations of coding and storage technology, the spherical panoramic video needs to be projected onto the two-dimensional plane for storage and encoding. In this paper, we propose a polar square projection scheme. We project the area near the poles of the sphere into two square planes and a latitude circle on sphere is projected to a square circle on squares plane, in addition, the rest of area on sphere is projected into a rectangle by means of equal area projection. Experimental results show our proposed projection can obtain a gain of 11.63% BD-rate compared to the equirectangular projection.