2125	 A Note on Minimal Length Polygonal Approximation to a Digitized Contour	 A method for extracting a smooth polygonal contour from a digitized image is illustrated. The ordered sequence of contour points and the connection graph of the image are first obtained by a modified Ledley algorithm in one image scan. A minimal perimeter polygon subjected to specified constraints is then chosen as the approximating contour. The determination of the minimal polygon can be reduced to a nonlinear programming problem solved by an algorithm which takes into account the weak bonds between variables. Some examples are presented and the corresponding computing times are listed. digitized image connection tree minimal polygon optimal approximation nonlinear programming
