Head-Motion-Aware Viewport Margins for Improving User Experience in Immersive Video

Viewport-dependent delivery (VDD) is a technique to save network resources during the transmission of immersive videos. However, it results in a non-zero motion-to-high-quality delay (MTHQD), which is the delta time from the moment where the current viewport has at least one low-quality tile to when all the tiles in the new viewport are rendered in high quality. MTHQD is an important metric in the evaluation of the VDD systems. This paper improves an earlier concept called viewport margins by introducing head-motion awareness. The primary benefit of this improvement is the reduction (up to 64%) in the average MTHQD.