European Conference on Visual Perception edition:25 location:Glasgow date:25-29 August 2002
Research on the colour conditions for perceptual transparency has focused on variants of the episcotister model proposed by Metelli. These additive models have been found to describe the luminance conditions for perceptual transparency in achromatic displays very accurately, but they are less successful in the chromatic domain. We propose an alternative psychophysical model that is based on filter transparency. A computer simulation revealed that this model does indeed describe colour relations that are found in situations where a surface is covered by a transparent filter more accurately than the additive model. In two psychophysical experiments we compared the predictions of the filter model directly with those of the additive model. In a four-colour stimulus, three colours were fixed in such a way that both models made unique and clearly different predictions for the remaining colour C. The subjects then searched for the colour C that optimised their impression of transparency. Our results show that the subjects' settings conform very closely to the predictions of the filter model and deviate systematically from those of the additive model. We therefore conclude that the filter model describes the colour conditions for perceptual transparency more accurately than the additive model.