A frame level metric for just noticeable temporal pumping artifact in videos encoded with the hierarchical prediction structure

At low bit-rates, video coding in the hierarchical prediction structure (HPS) using the quantization parameter cascading strategy will introduce the temporal pumping artifact (TPA). TPA presents itself as a stumbling visual effect and is caused by severe quality fluctuations among adjacent pictures. This paper proposes a frame level metric for just noticeable temporal pumping artifact (JNTPA) relying on the characteristics of temporal-spatial masking in the human visual system (HVS). The proposed metric quantitatively determines the TPA when it becomes visible. The experiments have demonstrated that the estimated JNTPA values for different videos using the proposed metric are in line with the HVS perception. An accurate estimation of the JNTPA can be used in video coding for avoiding the annoying TPA, and in perceptual quality evaluation for videos.