Equivalence Classes of Direction Objects and Applications

Abstract

Direction is an important spatial relationship that is used in many fields such as geographic information systems (GIS) and image interpretation. It is also frequently used as a selection condition in spatial queries. In our recent work we have described a novel viewpoint to model direction as a 'spatial object' based upon the concepts of vectors, points and angles. This was a departure from the conventional approach of treating direction as a spatial relationship between objects. In this paper, based upon 'direction objects', we partition the directional space into a set of equivalence classes. By defining an algebra on equivalence classes we provide a framework to model semantics of direction predicates for qualitative spatial reasoning. We then proceed to extrapolate the definition of direction equivalence classes to define `path' equivalence classes with an application to the landmark-based route description problem.

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Document Details

Document Type
Technical Report
Publication Date
Jul 21, 1999
Accession Number
AD1020026

Entities

People

  • Sanjay Chawla
  • Shashi Shekhar
  • Xuan Liu

Organizations

  • University of Minnesota

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Computer Graphics
  • Computer Science
  • Computers
  • Directional
  • Geographic Information Systems
  • Geometry
  • Graphics
  • High Performance Computing
  • Information Systems
  • Language
  • Military Research
  • Natural Languages
  • Navigation
  • Orientation (Direction)
  • Pattern Recognition
  • Reasoning
  • Two Dimensional

Fields of Study

  • Computer science

Readers

  • Computer Vision.
  • Graph Algorithms and Convex Optimization.
  • Theoretical Analysis.

Technology Areas

  • Space
  • Space - Space Objects