Depth seen with subjective contours

Subjective contours and apparent depth.

Schumann (1904) investigated the physical parameters which affect the perception of contour. He reported that for a contour to be perceived the prerequisite was some relatively abrupt local change in brightness or color. In the course of these investigations, however, he noted that under certain favorable conditions contours could be made to appear in areas of the visual field where the physica...

Subjective contours and apparent depth: a direct test.

however, explains such secondary effects associated with subjective contours as changes in brightness or in apparent depth. In contradistinction to the physiological explanations are a number of hypotheses that are primarily cognitive in nature. Kanizsa (1976) maintains that illusory contours are merely an unusually strong example of the Gestalt principle of closure. Other theorists suggest, ra...

Computing Depth Contours with Graphics Hardware

Drawing Depth Contours with Graphics Hardware

Depth contours are a well-known technique for visualizing the distribution of multidimensional point data sets. We present an image-space algorithm for drawing the depth contours of a set of planar points. The algorithm is an improvement on existing algorithms based on the duality principle, implemented using 3D graphics rendering techniques.

Shape Encoding and Subjective Contours

Ullman proposes that subjective contc,.us consist of two circles which meet smoothly and which arc tangential to the contrast boundaries from which they originate. The foim of the solution derives from a number of premises, one of which Ullman calls “the locality hypothesis”. ‘Ihis is “based in part on cxpcrimcntal obscrvntions, and partly on a theoretical consideration” ([I 51 ~2). ‘I’hc “cxpc...