One obstacle to the solution of these problems has been the lack of a robust representation for contours.The contour is represented by a set of pairwise tangent circular arcs.

• 本论文所针对的重建对象为以轮廓线主的二维影像，让使用者能更具体的看到这一些轮廓线事实上在人类的生活中所代表的真实情况。