A new colour appearance model for unrelated colours

In a series of psychophysical experiments the brightness, hue and “amount of white” perception of unrelated self-luminous stimuli was investigated. The “amount of white” is introduced as a new attribute in an attempt to find an alternative to colourfulness and saturation, attributes which are difficult to evaluate by laypeople without an intensive training. Based on the experimental visual data, a new colour appearance model for unrelated selfluminous stimuli, CAM15u, was developed. It was found that, despite its simplicity, CAM15u performs as well or better than other, more complicated, CAMs. Furthermore, the brightness perception of different sized, unrelated self-luminous stimuli was investigated. A significant, hue independent, effect of stimulus size on brightness was found, effectively modeled by a simple power function. The dependence of brightness on stimulus size was incorporated into the brightness prediction of the CAM15u model. It has been shown that the model can be a valuable tool to improve existing standards and guidelines describing the requirements for traffic signs, LED billboards, etc.status: publishe