Perceptual Versus Latitude-Based 360-Deg Video Coding Optimization
Sami Jaballah, Amegh Bhavsar, Mohamed–Chaker Larabi · 2020
In this paper, we present two optimization strategies for the improvement of 360-degree video coding efficiency. For the first strategy, the just noticeable difference dedicated to 360-degree images is obtained thanks to a novel framework relying on rectilinear projections. The estimated JND is incorporated as a weighting function for the 360Lib-VTM-4.0 RDO scheme in order to make its selection results more correlated with the human perception. The second strategy consists of a QP adjustment according to the latitude position in the sphere, where the incorporated weighting factor are modeled using the Von Mises Distribution. In order to evaluate the performance of both video coding optimization strategies, a set of experimental tests are performed using four high resolution 360-degree video sequences. The RDO-based JND strategy outperforms the anchor 360Lib9.0-VTM 4.0 while preserving the perceived image quality. Further, the latitude-based strategy achieves higher performance when compared to 360Lib9.0-VTM 4.0 and to a state-of-the-art approach [1], in terms of BD-rate of WS-PSNR and CPP-PSNR.