New definition and fast recognition of digital straight segments and arcs

The definition and recognition algorithm for a digital straight segment (DSS) is presented. The points of a DSS must have a limited distance from that edge. A recognition algorithm is given which uses only integer arithmetic and needs an average of about 10 such operations per point. The definition of a digital circular arc (DCA) which uses the notion of centers of the pixels (a pixel is considered as an elementary rectangular area) on both sides of a given curve is given. The centers comprise two sets: the left and the right. The curve is a DCA if a Euclidean circle separating the sets from each other exists. An efficient algorithm for finding all such circles is presented