Local surface slant determines perceived shape in pictures

Perceived shape and its dependency on perceived slant.

Koffka's suggestions that perceived shape and perceived slant "will be coupled together so that if one changes, the other changes also" and that errors in perceived shape vary as some function of errors in perceived slant were examined. Ss described, by means of appropriate response mechanisms, the shapes and slants of trapezoids. Shape and slant responses were made both monocularly and binocul...

Perceived surface shape not features determines correspondence strength in apparent motion.

Previous psychophysical studies have revealed that shape similarity can affect apparent motion correspondence. Such results however, do not specify the level of representation, at which shape similarity is defined. We sought to understand this question by using a 2 x 2 competitive apparent motion paradigm. We manipulated the binocular disparity of the motion stimuli (tokens) relative to adjacen...

On the relationship between deformation and perceived surface slant

A compelling impression of surface slant is produced by random dot displays depicting deformation and translation alone. A simple model of slant estimation based upon deformation is shown to capture quantitatively both the perceived slant in this situation and the distortion in perceived slant produced when constant deformation is added to random dot displays depicting moving slanted surfaces. ...

Shape Operator of Slant Submanifolds in Kenmotsu Space Forms

Visual discrimination of local surface structure: Slant, tilt, and curvedness

In four experiments, observers were required to discriminate interval or ordinal differences in slant, tilt, or curvedness between designated probe points on randomly shaped curved surfaces defined by shading, texture, and binocular disparity. The results reveal that discrimination thresholds for judgments of slant or tilt typically range between 4 degrees and 10 degrees; that judgments of one ...