Scan-in polygonal extraction of video images

Abstract From the Canadian patent

A video image is extracted and stored as a geometric figure by generating a binary pixel map of the image. The binary pixel map contains one bit for each pixel in the image represen-, tative of the value of a characteristic feature of that pixel relative to a threshold range. A crack following algorithm locates the border of a group of contiguous pixels all having the same binary value. This border defines the boundaries of the scanned image. It is smoothed by a recursive adaption technique to generate one or more polygons related to the shape of the image.