METHOD FOR AUTOMATIC RECOGNITION OF A CONCAVITY OR CONVEXITY

An automatic recognition method capable of accurately determining edges of a concavity or convexity in order to achieve an improved measuring accuracy in recognition of a concavity or convexity. This method comprises the steps of: converting a photographic image of an object having a concavity or convexity defined therein into data in a specified feature space; obtaining a plurality of points that exist outside a virtual circle determined by a virtual center of the concavity or convexity, the virtual center being established for each elementary area of the image converted into the feature space data; obtaining the equation of a plane that passes through the plurality of points; detecting symmetric pairs of pixels in each elementary area of the feature space data with respect to the corresponding virtual concavity or convexity center; and recognizing the position of the concavity or convexity of the object when the symmetric pixels satisfy the equation of the plane.