Patent ID: 6289126
Filing Date: 2001-09-11
Classification: G06K,G06T

Abstract:
A method for determining a boundary of an object based on its optically captured image, comprising the steps of:(a) converting a density data of each of a plurality of pixels forming the captured image into a binary signal;(b) converting the binary signal into a neighbor pixel state value so that only the pixels located on the boundary or in an interior of the object have a value corresponding to the binary signals of the surrounding pixels;(c) normalizing the neighbor pixel state value using an absolute chain direction value of a previous chain direction;(d) obtaining a relative chain direction value for pixel located on the boundary of the object in the image relative to the direction from which the chain has proceeded, with reference to the neighbor pixel state value of the pixel;(e) calculating an absolute chain direction value of a next chain direction on the basis of the relative chain direction value; and(f) repeating the steps (c) to (e) for each pixel located on the boundary to trace the boundary of the object.