Subjective video quality assessment of immersive HDR content on head-mounted displays

High dynamic range (HDR) videos are known to provide better visual quality on HDR TV displays. Head-mounted displays (HMDs) are an integral part of immersive visual experiences. However, typical HMDs are equipped with standard dynamic range (SDR) displays, failing to show details in bright and dark areas of HDR content. Therefore, we aim to evaluate the perceptual quality improvement, in terms of mean opinion score (MOS), when observers view HDR instead of SDR content on immersive displays. We developed a pipeline to render 2D HDR and tone-mapped SDR immersive videos for HMDs. We conducted two single-stimulus subjective evaluation experiments to evaluate (1) the perceived visual difference when comparing one HDR scene with three tone-mapped SDR versions of it, and (2) how frame rates impact the perceptual quality of HDR immersive videos. Our results in MOS show that (1) there is a significant improvement of perceptual quality in HDR compared to tone-mapped SDR content, and (2) HDR immersive videos benefit much more from higher frame rates than SDR videos.