To achieve optimal video quality under bandwidth and power constraints, modern video coding techniques employ lossy coding schemes, which often create compression artifacts that may lead to degradation of perceptual video quality. Understanding and quantifying such perceptual artifacts play important roles in the development of effective video compression, streaming and quality enhancement systems. Moreover, the characteristics of compression artifacts evolve over time due to the continuous adoption of novel coding structures and strategies during the development of new video compression standards. In this paper, we reexamine the perceptual artifacts created by standard video compression, summarizing commonly observed spatial and temporal perceptual distortions in compressed video, with emphasis on the perceptual temporal artifacts that have not been well identified or accounted for in previous studies. Furthermore, a floating effect detection method is proposed that not only detects the existence of floating, but also segments the spatial regions where floating occurs∗.