Perception of temporal pumping artifact in video coding with the hierarchical prediction structure

The usage of the hierarchical prediction structure in video coding has introduced a special type of temporal noise, i.e., the temporal pumping artifact. This artifact presents itself as severe quality fluctuations among adjacent pictures and is quite annoying due to the pumping or stumbling effect in perception. In this paper the fundamental reason of perception of the temporal pumping artifact is analyzed. The key factors influencing perception of temporal pumping artifact are evaluated based on subjective experiments, in terms of amplitude, frequency and phase of quality fluctuations, respectively. The detailed analysis suggests how the temporal pumping artifact can be well alleviated or even eliminated through adjusting coding parameters.