Thinning Contours

We must supply a list of control points to _1that will fit a Spline accurately to the original real-world feature. Therefore, we must decide which points contribute to the actual shape of the feature and which points are simply redundant.

Obviously, regions of high curvature are important to the overall shape of the feature, while low curvature regions will not play as important a role. We fit lines to each contour and represent them as polyline segments in _1. Each line only consists of its endpoints rather than all the image points along its length. All of the line segments and splines that make up a particular contour are combined together using the _1profile curve.

An example is in figure 3. The straight lines in this closed contour are found and the corner points are used as ``important'' points to the _1model. Points along the top arc are all used so that a spline can be fit to them accurately. The final region is represented as the combination of the lines and curves that make up its length.