Corner detection by means of contour local vectors

A corner detection algorithm for planar shapes based on a new curvature index is proposed. The calculation parameters of this new index are adapted to the shape curvature at each point of its contour. The process consists of estimating the maximum length of contour yielding no significant discontinuities on the right and left sides of each contour point in order to calculate the contour curvature index at that point. Thus, the curvature index is adaptively filtered depending on the natural scale of the contour pixels. Corners are detected by simply thresholding the curve. The proposed method provides a more precise characterisation of the contour. Detected corners are very stable against noise distortion, scaling or rotation.