Visual distortion assessment with emphasis on spatially transitional regions

It is known that the human visual system (HVS) does not pay equal attention to each error and even region in judging picture quality. In this paper, we combine a perceptual model with an integrated detection of the spatially transitional regions in visual distortion evaluation to better match the HVS perception to visual quality. For decompressed images or video, the spatially transitional regions are the regions where major perceptually disturbing artefacts caused by edge impairments (mainly due to blurring and locations where the edge information is not adequately represented) and the presence of false edges (mainly due to blockiness and the presence of strong rippling effects of ringing) usually occur. Such regions are efficiently detected based on a single two-dimensional spatial high-pass filter in our work. Good correlation between the proposed method and the human perception has been demonstrated with the full set of 50-Hz video quality expert group test data.