Visual extrapolation of contour geometry

Visual extrapolation of contour geometry.

Computing the shapes of object boundaries from fragmentary image contours poses a formidable problem for the visual system. We investigated the extrapolation of contour shape by human vision. Measurements of extrapolation position and orientation were taken at six distances from the point of occlusion, thereby yielding a detailed representation of the extrapolated contours. Analyses of these me...

Supporting information for: Visual extrapolation of contour geometry

Computational Geometry of Contour Extraction

We present a method for extracting contours from digital images using techniques from computational geometry. Our approach is different from traditional pixelbased methods in image processing. Instead of working directly with pixels, we extract a set of oriented feature points from the input digital images, then apply classical geometric techniques such as clustering, linking, and simplificatio...

Bayesian contour extrapolation: Geometric determinants of good continuation

We investigated whether observers use rate of change of curvature in visually extrapolating contour shape. Arcs of Euler spirals with positive or negative rate of change of curvature gamma (hence linearly increasing or decreasing curvature) disappeared behind the straight-edge of a half-disk occluder. Observers adjusted the position and the orientation of a line probe around the curved portion ...

Contour Matching Using Epipolar Geometry

Generally contour matching is diicult, and the problem becomes more diicult when the motion between successive image frames is large. When the image frames are obtained while the camera is in motion, we can use constraints about the scene and the camera. In this paper we propose a contour matching algorithm which guarantees an accurate matching result, even for large motion contours. The key id...