Shape completion

This report describes some simple techniques for smoothly filling in gaps in object contours. The first technique considered was recently proposed by Ullman; it constructs the completion of the contour using two arcs of circles that are tangent to the gap ends and to each other, and that have minimum total curvature. An analysis of this technique is presented, and examples of its use are given. A second technique uses cubic polynomial completions; when suitably constrained, this technique yields very reasonable completions.