Abstract
In this paper we present a method for representing a continuous curve in the plane by a function defined on a unit interval, which we call the angular characteristic function of the curve. This representation is invariant under translations, rotations and universal scaling and is well suited for curve shape recognition. We have used this function for feature extraction in an experimental system for optical recognition of handwritten characters and the approach, briefly described in this paper, has shown good results. For graphic primitives - circular arcs and line segments - the angular characteristic function representing them has a particularly simple form. This circumstance allows using the angular characteristic function in motion planning problems and in robotics. As an example of such applications, we present an algorithm that can be used in a system for automatic program generation for a robotic manipulator used for a cutting process. This is an algorithm for approximating a smooth curve in the plane by a sequence of such graphic primitives forming a continuous smooth curve (in which each segment is conjugate to its neighbors).