This work addresses the problem of studying and characterizing individual artifacts found in digital video applications (e.g., blockiness, blurriness). In particular, the goal of this paper was to examine the properties of synthetic blocky and blurry artifacts, designed to be relatively pure, and a combination of these two artifacts. We performed a psychophysical experiment in which human subjects were asked to detect these artifacts, identify their types, and rate their annoyance. In most cases, the blocky and blurry artifacts were identified as blocky and blurry, respectively. In combined blocky-blurry artifacts the salience of blockiness increased and blurriness decreased as artifact strength increased. The blocky artifacts produced higher annoyance values than the blurry ones when the total squared error was the same.