Subjective quality of spatially asymmetric omnidirectional stereoscopic video for streaming adaptation

Asymmetric video coding is a well-studied area for bit rate reduction in stereoscopic video coding. Such video coding technique is possible because of the binocular fusion theory which states that the Human Visual System (HVS) is capable of fusing views from both the eyes. As a result, past literature has shown that the final perceived quality of different left and right quality images is closer the highest quality of the two views. In this paper, we investigate spatially asymmetric omnidirectional video in subjective experiments using a Head Mounted Display (HMD). We want to subjectively verify to what extent the binocular fusion theory applies in immersive media environments, and also assess to what degree reducing the omnidirectional video streaming bandwidth is feasible. We prove that (1) the HVS is capable of partial suppression of the low-quality view up to a certain resolution; (2) there is a bandwidth saving of 25% when 75% of the spatial resolution is used for one of the views, while ensuring a subjective visual quality with a DMOS of 4.7 points; (3) in case of bandwidth adaptation using asymmetric video, bit rate savings are in the range 25–50%.