A-09 Calibration of reflectance map when the light source exists in the direction of viewer

Abstract

Subjects observed images of cylinders illuminated from the viewer direction, and judged surface slant and crosssectional shape of perceived shapes. The reflectance maps used by the visual system were estimated from the relationship between the perceived shapes and the stimulus image intensity. The reflectance maps obtained from the judged slant varied depending on the stimuli, but those from the judged crosssectional shape were almost the same. These results suggest that when the light source exists in the viewer direction, the reflectance map is calibrated for slant perception, but a 'default' reflectance map is used for depth perception.