In order to quantify the ability of the human visual system to use texture information to perceive planar surface orientation, I measured subjects' ability to discriminate planar surface slant (angle away from the fronto-parallel) for a variety of different types of textures and in a number of different viewing conditions. I measured the subjects' discrimination performance as a function of sur...

Rotating a surface about a horizontal axis alters the retinal horizontal-shear disparities. Opposed torsional eye movements (cyclovergence) also change horizontal shear. If there were no compensation for the horizontal disparities created by cyclovergence, slant estimates would be erroneous. We asked whether compensation for cyclovergence occurs, and, if it does, whether it occurs by use of an ...

In order to quantify the ability of the human visual system to use texture information to perceive planar surface orientation, I measured subjects’ ability to discriminate planar surface slant (angle away from the fronto-parallel) for a variety of different types of textures and in a number of different viewing conditions. I measured the subjects’ discrimination performance as a function of sur...

Since judgment of geographical slant requires the use of both optical and postural information, such judgments were used to determine whether intermodal relationships affect children’s perception. First, third, and fifth graders made judgments of geographical slant of surfaces depicted in photographs either with or without postural inclination. The results indicate the existence of a linear mec...

The slant of a stereoscopically defined surface cannot be determined solely from horizontal disparities or from derived quantities such as horizontal size ratio (HSR). There are four other signals that, in combination with horizontal disparity, could in principle allow an unambiguous estimate of slant: the vergence and version of the eyes, the vertical size ratio (VSR), and the horizontal gradi...

The work presented in this paper is a rst attempt at evaluating an ordinal representation for the local shape of smooth surface patches. To this end we investigate the reliability of estimating the tilt and slant components of the local surface orientation from binocular parallax. This is of interest because parallax is a commonly used cue, but has not been evaluated as to its susceptibility to...