Colour Appearance Modelling for Self-Luminous Colours.

The assessment of the quality and comfort of lighting requires a good understanding of the correlation between the optical properties of the stimuli, such as luminance, and their corresponding perceptual attributes, such as brightness, hue, colourfulness, lightness, chroma and saturation. To facilitate this, colour appearance models have been developed that simulate many of the physiological processes that take place in the human visual system. The colour of objects originates from the interaction between a light source and the physical properties of the object. Object colours (or surface colours) belong to the category of so-called related colours because they are perceived within the context of other colours such as the colour of the illuminant. For these stimuli, a colour appearance model was developed in 2002, i.e. CIECAM02, which has been widely accepted by the international community. It has been applied in printing and display technology to reproduce the correct colour appearance of images under different viewing conditions. However, there is at present no agreed model for the evaluation of self-luminous stimuli, such as light sources, seen against a luminous background, although this situation occurs frequently in everyday situations such as self-luminous panels and walls using LEDs, traffic signals and advertisements viewed both by day and by night. The aim of this project is to gather physical and visual data for these kinds of stimuli through measurements and observer assessments respectively. From these data, an improved or new colour appearance model will be developed which will increase our understanding of the mechanisms of perception of light sources seen in relation to other emissive sources. In the long term, this model will provide an interesting tool to describe the visual experience of the total lit environment.

Keywords:Colours, Selfluminous stimuli, Colour appearance, Colourfullness, Helmholtz-kohlrausch, Brightness

Disciplines:Other biological sciences, Other natural sciences