抄録
To perceive shape from shading correctly, information about the direction of illumination is needed. We investigated how the direction from visual information affects perceiving shape from shading and how we estimate the direction of illumination using both visual information and the Light-from-above assumption. The results showed that the information about the direction of illumination was extracted from the surrounding visual stimuli and that the area within, where this information propagated, was limited. In addition, even when the explicit visual information about the direction of illumination was available, the Light-from-above assumption also worked, at least in some situations.The effect of assumption was enhanced by the surrounding stimuli with luminance gradation. These results indicate that the configurations of visual stimuli largely affect the estimation of the direction of illumination for shape from shading.
