The Illuminant Estimation Hypothesis and Surface Colour Perception

The degree of surface colour constancy that we experience depends on viewing conditions: under some circumstances, we have essentially none, and under others, we show a remarkable, nearly perfect, degree of constancy. This chapter considers an analogous explanation for failures and successes of surface colour perception, based on the illuminant estimation hypothesis. An evident implication of this illuminant estimation hypothesis is that the number and strength of illuminant cues present in a scene limit the degree of colour constancy possible: little colour constancy is possible in scenes devoid of illuminant cues. If a colour visual system fails to make use of the cues available, we would also expect errors in surface colour perception as a consequence.