Versatile Video Coding of 360º Video using Adaptive Resolution Change

Encoding 360º video with ultra high spatial resolution requires high bitrates to guarantee acceptable QoE in video delivery services. However, since in general the full Field-of-View (FoV), i.e., 360º, is not required at once, a great deal of bandwidth can be saved if only a limited FoV is delivered, according to content relevancy or/and user demand. This work addresses this problem using the concept of Adaptive Resolution Change (ARC) defined in the forthcoming Versatile Video Coding (VVC) standard, by dynamically mapping the full FoV into multiple video frames with different spatial resolutions. Those FoVs attracting more visual attention are encoded with higher resolution while the others are encoded with lower resolution, thus without compromising the visual quality and resolution of the most relevant regions. The simulation results show that the proposed adaptive coding scheme is able to deliver high quality video for the most relevant FoV at any time instant, achieving a maximum bitrate reduction of 37.2%.