Perceptual prefiltering is the process of enhancing relevant portions of an image or of a video, and of simplifying contextual information in order to improve the perceived quality or the compression ratio. In this paper, we discuss the results of subjective quality evaluation experiments performed to assess the impact of perceptual prefiltering on video coding and we propose an objective quality metric that mimics the behavior of human observers. The predicted performance of the proposed metric is consistent with the subjective evaluation scores. Experimental results demonstrate that perceptual prefiltering leads to quality improvements by up to 10% at low bitrates.