title: Systematic distortions of shape from stereopsis.
abstract: The effectiveness of disparity information in defining 3-D shape was investigated by means of judgements of the shape of cylindrical continuous curved surfaces presented as random dot stereograms. At a close viewing distance, truly circular cylinders appeared elongated; at an intermediate distance, perception was close to veridical; and, at a far distance, cylinders appeared flattened. Indirect measures of scaling distance were calculated from these data. The results strongly suggest that the observed shape distortions are a consequence of scaling horizontal disparities with an incorrect measure of egocentric distance.
authors.affiliation: University Laboratory of Physiology, Oxford, U.K.
authors.forename: E B
authors.initials: EB
authors.lastname: Johnston
mesh_terms: D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D008433:Mathematics; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010469:Perceptual Distortion / Q000502:physiology*; D011594:Psychometrics; D015357:Vision Disparity / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology