Gradual Chroma Reduction and High-Level Visual Masking in Videos

This study investigates the inability of the human vision system to detect gradual changes in video quality, specifically chroma reduction. We present the results from a subjective study, in which participants compared video stimuli of three different types: pristine, mildly chroma-reduced background with a fixed rate, chroma reduced with a gradual rate from a pristine first frame to a fully achromatic background in the last one. Our results show that the second type yields quality ratings that are significantly lower than those of the gradually modified samples, which are on par with those of the pristine samples.