Perceptual Convexity
نویسندگان
چکیده
Often objects which are not convex in the mathematical sense are treated as`perceptually convex'. We present an algorithm for recognition of the perceptual convexity of a 2-d contour. We start by reducing the notion ofà contour is perceptually convex' to the notion ofà contour is Y-convex'. The latter reeects an absence of large concavities in the OY direction of an XOY frame. Then we represent a contour by a G-graph and modify the slowest descent-the small leaf trimming procedure recently introduced for the estimation of shape similarity. We prove that executing the slowest descent down to a G-graph consisting of 3 vertices allows us to detect large concavities in the OY direction. This allows us to recognize the perceptual convexity of an input contour.
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