Studying human behavioural responses to time-varying distortions for video quality assessment

Advances in video quality assessment have shown the added value of including temporal aspects of artifact perception in its objective metrics. The impact of quality variations over time and the associated implications for the assessment of overall video quality are so far not fully understood yet. To investigate the human behavioural responses to time-varying distortions and the relevance of such perception to overall quality judgements, a series of subjective experiments were conducted. In the major experiment, 30 human subjects scored the overall quality of 120 stimuli, which consist of 84 videos of various time-varying quality profiles and of their corresponding 36 constituent segments of spatio-temporally constant quality. Results show that the pattern of quality variations over time tends to affect the temporal summation strategy that delivers an overall quality.