Acta Geodaetica et Cartographica Sinica

Previous Articles     Next Articles

A Qualitative Model of Directional Relations Based on Topological Constraint

  

  • Received:2012-08-16 Online:2014-04-20 Published:2014-02-18
  • Supported by:

    ;Program granted for scientific innovation research of college graduate in Jangsu province

Abstract:

Directional relation is one of the most important characters of spatial objects and is useful for spatial retrieval, analysis and reasoning. For line and area reference objects, the directional reference is distinct in the different topological area. However, existing models ignore this difference and represent the direction relations based on the same reference in the whole region of MBR (minimum bounding rectangle). To overcome the problems of direction-relation representation in the MBR of reference object, this paper extend the model of direction-relation matrix and propose a new model based on topological restraint. The new model, called the hierarchical direction-relation matrix based on topological restraint, retains three direction-matrixes with empty and non-empty tiles, which record direction-relation codes for three topological regions. The new qualitative model is based on the topological restraints to direction-relation definition, in which (1) the minimum bounding rectangle of reference object is decomposed into three topological regions (i.e. exterior, boundary and interior); (2) topological references are defined to discribe the alteration of directional reference in three topological regions; (3) three direction-relation matrixes (i.e. exterior, boudary, interior direction-relation matrix) are utilized to represent the directional relations of three topological regions; and (4) a hierarchical calculative approach is proposed for discription of direction relations between different topolical spatial objects to improve the computational efficiency. The new model overcomes the discription difficulty of directional relations bewteen objects of complex topological relations and improve the accuracy and veracity of direction relations models.

Key words: Directional relations, Qualitative Description, Minimum bounding rectangle of reference object, Topological reference for direction-relation, Direction-relation hierarchical matrix model based on topological reference

CLC Number: