EXTRACTING CONTOURS BY PERCEPTUAL GROUPING

A new contour extraction method is described in this paper. It is based on organization of the image data using perceptual grouping rules, and is therefore largely domain independent. The first step is to form an intermediate line segment representation of the contours by grouping edge points in parallel and at different resolutions. The main feature of the line segment extraction process is the identification, by perceptual criteria, of weak but significant edge points for participation in the grouping process. In the second stage the line segments are grouped into contours, again on the basis of perceptual criteria. This grouping stage is carried out hierarchically using a pyramid structure. In both cases, the use of perceptual grouping allows the filtering of noisy edges and line segments regardless of their strength.