Influence of Display Devices and Field of View on Subjective Quality of Experience Evaluation of 8K 360° Videos

As 360° videos are gradually gaining popularity, various display devices have emerged for watching 360° videos, including both head-mounted displays (HMDs) and touchscreen displays. While several experiments have been conducted to examine the quality of experience (QoE) of watching 360° videos using HMDs, the QoE when using touchscreen displays has not been examined thoroughly. In this work, we conducted subjective evaluation experiments to examine the influence of an HMD and touchscreen display, including the influence of scaling when using the touchscreen display, on the QoE when watching 8K 360° videos encoded via high efficiency video coding (HEVC) at various bitrates. The results show that better QoE scores are obtained (1) when using the HMD than when using the touchscreen display without scaling and (2) when enabling scaling on the touchscreen display than when disabling scaling at lower bitrates. Moreover, we examined the relationship between the QoE and other factors, such as the video quality and sense of presence. Our analysis revealed that when watching 360° videos on the touchscreen display, the QoE is more strongly associated with the sense of presence than with the video quality, particularly when scaling is enabled.