Symmetry (May 2022)

A Hierarchical Universal Algorithm for Geometric Objects’ Reflection Symmetry Detection

  • Borut Žalik,
  • Damjan Strnad,
  • Štefan Kohek,
  • Ivana Kolingerová,
  • Andrej Nerat,
  • Niko Lukač,
  • David Podgorelec

DOI
https://doi.org/10.3390/sym14051060
Journal volume & issue
Vol. 14, no. 5
p. 1060

Abstract

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A new algorithm is presented for detecting the global reflection symmetry of geometric objects. The algorithm works for 2D and 3D objects which may be open or closed and may or may not contain holes. The algorithm accepts a point cloud obtained by sampling the object’s surface at the input. The points are inserted into a uniform grid and so-called boundary cells are identified. The centroid of the boundary cells is determined, and a testing symmetry axis/plane is set through it. In this way, the boundary cells are split into two parts and they are faced with the symmetry estimation function. If the function estimates the symmetric case, the boundary cells are further split until a given threshold is reached or a non-symmetric result is obtained. The new testing axis/plane is then derived and tested by rotation around the centroid. This paper introduces three techniques to accelerate the computation. Competitive results were obtained when the algorithm was compared against the state of the art.

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