Effects of Luminance and Color Conditions on Color Spreading in Flank Transparency Displays

摘要

Adding narrow colored flanks to black lines where these lines fall within a virtual square induces the perception of a colored transparent square with illusory contours, an illusion called flank transparency (Wollschlager et al., 2001). We investigated luminance and color conditions for the perception of color spreading in a static flank transparency display. Luminances of the flanks, lines, and background in the display were systematically varied. The flanks were either colored (green) or achromatic, and the lines and background were always achromatic. Observers rated the certainty of color spreading with a five point scale. The results revealed that color spreading depended upon color as well as luminance conditions. Moreover, the results could mostly be accounted for by an episcotister model of perceptual transparency generalized to a cone contrast metric; i.e., color spreading was reported when the color conditions in the display satisfied the conditions predicted by the model. Consistently with the findings using neon color spreading displays (Ekroll & Faul, 2002), the present findings suggest that perceptual scission of color and luminance information in a flank region into a transparent layer and a background plays a critical role in producing color spreading in flank transparency displays.