Polynomial/Rational Approximation of Minkowski Sum Boundary Curves

In Kwon Lee, Myung Soo Kim, Gershon Elber

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88 Citations (Scopus)


Given two planar curves, their convolution curve is defined as the set of all vector sums generated by all pairs of curve points which have the same curve normal direction. The Minkowski sum of two planar objects is closely related to the convolution curve of the two object boundary curves. That is, the convolution curve is a superset of the Minkowski sum boundary. By eliminating all redundant parts in the convolution curve, one can generate the Minkowski sum boundary. The Minkowski sum can be used in various important geometric computations, especially for collision detection among planar curved objects. Unfortunately, the convolution curve of two rational curves is not rational, in general. Therefore, in practice, one needs to approximate the convolution curves with polynomial/rational curves. Conventional approximation methods of convolution curves typically use piecewise linear approximations, which is not acceptable in many CAD systems due to data proliferation. In this paper, we generalize conventional approximation techniques of offset curves and develop several new methods for approximating convolution curves. Moreover, we introduce efficient methods to estimate the error in convolution curve approximation. This paper also discusses various other important issues in the boundary construction of the Minkowski sum.

Original languageEnglish
Pages (from-to)136-165
Number of pages30
JournalGraphical Models and Image Processing
Issue number2
Publication statusPublished - 1998 Mar

Bibliographical note

Funding Information:
1The research was supported in part by the Korean Ministry of Science and Technology under Grants 96-NS-01-05-A-02-A and 96-NS-01-05-A-02-B of STEP 2000, and by KOSEF (Korea Science and Engineering Foundation) under Grant 96-0100-01-01-2.

All Science Journal Classification (ASJC) codes

  • Modelling and Simulation
  • Computer Vision and Pattern Recognition
  • Geometry and Topology
  • Computer Graphics and Computer-Aided Design


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