An algorithm has been discussed which can identify the mechanical parts using curvature description. It is assumed that well processed contours of mechanical parts are available from any other edge detection algorithm. These compact contours can be used for forming a model under favorable viewing conditions or for identifying a part by a matching process that uses a previously formed model.
We use the curvature as a descripter along the contour, and normalize it to make it insensitive to size variations. To find the curvature, original contour is transformed to the θ-s (Angle Displacement) plane on which the curvature means a slope of a curve. Then, the HOUGH Transform is employed locally to fit the each segment which is cut through a segmentation algorithm on the θ-s plane.
A measure of similarity is defined, and its variation with respect to sizes and angles of objects are discussed.