Colour constancy in perceptual transparency has been mostly studied using filters partially superimposed on variegated stimuli, that is, on stimuli with areas having one part visible directly and the other part visible through the filter. The problem of whether colour constancy also occurs when variegated stimuli are completely covered by a filter has been studied less often and with mixed results. In two experiments we found that the grey colours of the areas of an achromatic Mondrian completely covered by an achromatic filter differ from the expected grey colours, that is, the grey colours of the respective areas of the same Mondrian viewed without the filter. Our results show poor achromatic colour constancy. Depending on the filter and the colour of the areas of the Mondrian, the grey colours of the Mondrian seen through the filter shifted from the expected grey colour by up to more than two Munsell steps in the 10-step grey scale. We also found that the achromatic colour shifts caused by failure of constancy were asymmetrical. That is, under the filter, the lighter areas were darker and the darker areas were lighter than expected. This asymmetry occurred both when the background outside the filter was white or black.
LIGHTNESS CONSTANCY UNDER ACHROMATIC FILTERS
DA POS, OSVALDO;
2009
Abstract
Colour constancy in perceptual transparency has been mostly studied using filters partially superimposed on variegated stimuli, that is, on stimuli with areas having one part visible directly and the other part visible through the filter. The problem of whether colour constancy also occurs when variegated stimuli are completely covered by a filter has been studied less often and with mixed results. In two experiments we found that the grey colours of the areas of an achromatic Mondrian completely covered by an achromatic filter differ from the expected grey colours, that is, the grey colours of the respective areas of the same Mondrian viewed without the filter. Our results show poor achromatic colour constancy. Depending on the filter and the colour of the areas of the Mondrian, the grey colours of the Mondrian seen through the filter shifted from the expected grey colour by up to more than two Munsell steps in the 10-step grey scale. We also found that the achromatic colour shifts caused by failure of constancy were asymmetrical. That is, under the filter, the lighter areas were darker and the darker areas were lighter than expected. This asymmetry occurred both when the background outside the filter was white or black.Pubblicazioni consigliate
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