Abstract
We rarely view pictures from their original projective distance, i.e. from the center of projection (CoP). Nonetheless, the scene perceived from a picture seems to be like the depicted scene. Why does pictorial scene perception seem resistant to changes in viewing distance? The retinal image is altered by changing viewing distance. Thus, if the viewer only used the retinal image associated with a surface in the picture, the surface slant would be misperceived when viewed from the wrong distance. For example, slant would be overestimated when viewing from farther than the CoP. The pictorial-compensation hypothesis (e.g. Kubovy, 1986; Sedgwick, 1980) states how viewers might compensate for incorrect distance. Pictorial cues (e.g. rectilinear structure in the depicted scene) locate the CoP and then used to effectively transport the viewer to the correct position. The compensation hypothesis thus predicts that surface slant would not be overestimated when viewing from farther than the CoP. We trained observers to judge the slant of an upright rectangle in a scene rich with pictorial cues. They made judgments at different distances (including the CoP distance) with monocular and binocular viewing. The visual angle of the stimulus was constant across viewing distance. With both monocular and binocular viewing, slant was estimated correctly at the CoP distance and was overestimated at longer distances. Thus, we found no evidence for the pictorial-compensation hypothesis, even when the picture contained rich pictorial information and the distance to the picture was specified by binocular disparity.
DOE CSGF (for ARG), NIH NRSA (for DV)