Multisensory 360° Videos Under Varying Resolution Levels Enhance Presence

Omnidirectional videos have become a leading multimedia format for Virtual Reality applications. While live 360<inline-formula><tex-math notation="LaTeX">$^\circ$</tex-math><alternatives><mml:math><mml:msup><mml:mrow/><mml:mo>∘</mml:mo></mml:msup></mml:math><inline-graphic xlink:href="covaci-ieq2-3140875.gif"/></alternatives></inline-formula> videos offer a unique immersive experience, streaming of omnidirectional content at high resolutions is not always feasible in bandwidth-limited networks. While in the case of flat videos, scaling to lower resolutions works well, 360<inline-formula><tex-math notation="LaTeX">$^\circ$</tex-math><alternatives><mml:math><mml:msup><mml:mrow/><mml:mo>∘</mml:mo></mml:msup></mml:math><inline-graphic xlink:href="covaci-ieq3-3140875.gif"/></alternatives></inline-formula> video quality is seriously degraded because of the viewing distances involved in head-mounted displays. Hence, in this article, we investigate first how quality degradation impacts the sense of presence in immersive Virtual Reality applications. Then, we are pushing the boundaries of 360<inline-formula><tex-math notation="LaTeX">$^\circ$</tex-math><alternatives><mml:math><mml:msup><mml:mrow/><mml:mo>∘</mml:mo></mml:msup></mml:math><inline-graphic xlink:href="covaci-ieq4-3140875.gif"/></alternatives></inline-formula> technology through the enhancement with multisensory stimuli. 48 participants experimented both 360<inline-formula><tex-math notation="LaTeX">$^\circ$</tex-math><alternatives><mml:math><mml:msup><mml:mrow/><mml:mo>∘</mml:mo></mml:msup></mml:math><inline-graphic xlink:href="covaci-ieq5-3140875.gif"/></alternatives></inline-formula> scenarios (with and without multisensory content), while they were divided randomly between four conditions characterised by different encoding qualities (HD, FullHD, 2.5K, 4K). The results showed that presence is not mediated by streaming at a higher bitrate. The trend we identified revealed however that presence is positively and significantly impacted by the enhancement with multisensory content. This shows that multisensory technology is crucial in creating more immersive experiences.