Factors contributing to depth perception: behavioral studies on the reverse perspective illusion

In three behavioral experiments using depth-inverted visual stimuli, the factors that contribute to the 'reverse perspective' illusion were measured. The density of linear perspective grid lines was found to induce the illusion most strongly, followed by shading/shadows, and texture/color information. The relative contributions of such pictorial cues to depth perception are similar to those that facilitate the normal perception of 3D space in 2D paintings.