Temporal Motion Smoothness and the Impact of Frame Rate Variation on Video Quality

There has been a strong recent trend to improve the perceptual quality-of-experience of viewers by expanding the spatial resolution, dynamic range, color gamut, and frame rate of videos. Conceptually, increasing video frame rate should create a benefit of smoother perception of motion. However, how to measure motion smoothness is not a well resolved problem. In this study, we measure the smoothness of motion by examining the local phase correlation of complex wavelet coefficients along the temporal direction. Our experiments based on subjective-rated databases show that this novel measure provides a new means to capture the impact of frame rate on video quality, and demonstrates strong promise at improving the performance of objective video quality assessment models.