Detectability and annoyance of synthetic blurring and ringing in video sequences

One approach for studying digital video impairments is to work with synthetic artifacts which look like real impairments, yet are simpler, purer and easier to describe. We have created synthetic ringing and blurring and inserted them in short video sequences. In a psychophysical experiment, we measured the probability of detection and the annoyance value of these artifacts as a function of their total squared error. Although ringing occurs only near edges and blurring can occur over wide areas of the images, there is no consistent difference between either the thresholds or mid-annoyance strengths. There are, on the other hand, interactions between the specific video and artifact type in the determination of these values. Mid-annoyance strength was found to be highly correlated with threshold. Also, we combined ringing and blurring to produce mixed artifacts. Their thresholds and mid-annoyance strengths tend to be intermediate between those of the individual artifacts. Their annoyance value is well predicted by a weighted sum of the annoyance values for blurring and ringing with weights of approximately 0.6 and 0.4, respectively.