High-speed spline fitting, with application to boundary tracing in low-contrast digital images

The practical implementation of a rapid Catmull-Rom (cardinal) spline is described, and its advantages with respect to speed and ease of use are discussed. Consideration is also given to interactive tensioning of the curve, and how the spline may be used to contour the boundary in digital images prior to segmentation. For this purpose the spline control points are positioned by the user and automatically optimized by means of a local, two dimensional edge detector.