High Frame Rates and the Visibility of Motion Artifacts

Abstract

Video frame rates, higher than those in conventional use today, have been shown to lead to an increase in perceived quality due to a reduction in the visibility of motion artifacts, specifically motion blur and temporal aliasing. Despite this, frame rates used in television and cinema have remained constant for many years. Although not currently in widespread use, the most recent ultrahigh-definition television (UHDTV) video standard (International Telecommunications Union-Radiocommunication (ITU-R) Recommendation BT. 2020) specifies a higher spatial resolution and a wider dynamic range than its predecessor; it also supports frame rates up to 120 Hz. In this context, we investigate the influence of temporal sampling rate on the visibility of aliasing artifacts. Our results show that impairments in motion quality can be tolerated to a degree, and that it is acceptable to sample at frame rates 50% lower than the critical frame rate (CFR)—the point at which motion artifacts become perceptible. Based on real-world data related to median viewing distances and screen sizes, we make the recommendation that frame rates should be at least 100 Hz in future immersive video formats. Two further experiments show how the CFR is dependent on both stimulus size and luminance. With respect to luminance dependence, our results indicate that the CFR for a bright high-dynamic range display may be 30% higher than that for a conventional low-dynamic range display.