International Workshop on Combinatorial Algorithms

IWOCA 2014: Combinatorial Algorithms pp 140-152 | Cite as

A 3-Approximation Algorithm for Guarding Orthogonal Art Galleries with Sliding Cameras

  • Stephane Durocher
  • Saeed MehrabiEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8986)


A sliding camera travelling along a line segment s in a polygon P can see a point p in P if and only if p lies on a line segment contained in P that intersects s at a right angle. The objective of the minimum sliding cameras (MSC) problem is to guard P with the fewest sliding cameras possible, each of which is a horizontal or vertical line segment. In this paper, we give an \(O(n^3)\)-time 3-approximation algorithm for the MSC problem on any simple orthogonal polygon with n vertices. Our algorithm involves establishing a connection between the MSC problem and the problem of guarding simple grids with periscope guards.


Slider Camera Simple Orthogonal Polygon Maximal Line Segment Pocket Edge Grid Segment 
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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.Department of Computer ScienceUniversity of ManitobaWinnipegCanada

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