Detectability and Annoyance of Synthetic Blocky, Blurry, Noisy, and Ringing Artifacts

This paper presents the results of a series of four psychophysical experiments carried out to study the appearance, annoyance, and detectability of common digital video compression artifacts. The approach chosen in this paper was to use synthetic artifacts that look like "real" artifacts, yet are simpler, purer, and easier to describe. This approach allowed the control of the amplitude, distribution, and mixture of different types of artifacts. The algorithms for generating four of the most common types of artifacts: blockiness, blurriness, ringing, and noisiness, are described. The psychophysical experiments performed used video sequences containing different combinations of the generated synthetic artifacts. In these experiments, subjects were asked to detect any impairment and rate its annoyance. With the data gathered, the probability of detection and annoyance values were determined as a function of the total squared error. The results showed that "original video" (content) has a significant effect on both the detection threshold and the mid-annoyance parameter, while the "artifact signal type" does not. It was also found that these two parameters are highly correlated and linearly related