Separating the effects of glare from simultaneous contrast

摘要

Appearance in High Dynamic Range images is controlled by intraocular glare and physiological spatial contrast. Increasing the number of high luminance pixels in a display increases glare and reduces the dynamic range of luminances on the retina. Simultaneous contrast makes areas with higher glare related luminances look darker. Previous experiments measured the range needed for the appearance black in surrounds with variable percentage of white pixels in the background. In these test targets it was 2.0 log units with 100% white pixels, 2.3 log units with 50% white pixels, 2.9 log units with 8% white pixels, and 5.5 log units with 0% white pixels. We want to calculate the intensity of veiling glare in these test scenes and relate retinal luminances to the magnitude estimates of appearance reported by observers. This paper uses a glare spread function to calculate the retinal luminances after intraocular scatter. By modeling the actual luminances on the retina we can compare them with appearance.