SPATIALLY ADAPTIVE INTRA MODE PRE-SELECTION FOR ERP 360 VIDEO CODING

In this work, we propose a spatially adaptive HEVC intra mode pre-selection for equirectangular (ERP) 360 video coding. The proposed technique exploits the spatial characteristics of 360 video in the ERP projection to reduce the complexity of intra prediction mode selection. The number of intra modes evaluated in Rate-Distortion Optimization is reduced based on a score technique that is adaptive to the frame region being encoded. Results show that the proposed technique achieves a complexity reduction of 16.5% with low coding efficiency penalties.