Abstract
Color ambiguity in the photo "#TheDress" has been considered as a special case due to its specific color distribution because only few other images turned out to induce similar effect. This study demonstrates "T-shirt" images to induce the similar effect by physically-based rendering with manipulating illuminant cue. Mitsuba-Renderer was used to generate the images of pink/gray striped T-shirts. Illuminant color was varied from white to greenish so that the reflected light from the pink and gray parts of the T-shirt become gray and green. Note that the same color reflection occurs when the "gray/green" T-shirt is illuminated by pinkish to white light. Thus without any illuminant cues, color constancy may fail. To confirm in the Exp.1, observers were asked to name the colors of each part of the pink/gray T-shirt image, rendered under various illuminant colors, displayed on black background. Exp.2 used the gray/green T-shirts image rendered under pinkish to white illuminant with achromatic floor and wall expected to work as a relevant illuminant cue. In Exp.3, the illuminant cue was given indirectly by a reference pink/gray T-shirt rendered under more pinkish illuminant, placed on the other side of the target image on black background. In Exp.1, color naming was stable and biased to either pink/gray or gray/green across individual observers, implying that there was a minimal illuminant cue inside of the T-shirt stabilizing the color percept, but that cue was used differently by individuals. Both in Exp. 2 and 3, cues modulated the color naming: less pink/gray and more gray/green responses were obtained, with color percept switched from pink/gray to gray/green within some observers. In conclusion, we found a systematic way 1) to generate other images to induce #TheDress-type effects and 2) to switch observers' color percept, providing a new approach to the underlying mechanisms of color ambiguity.
Meeting abstract presented at VSS 2018