The spread function is a powerful operation for analysing a wide range of phenomena considered in geographical information systems (GIS). One important and common application of the spread functions is the calculation of distance on a map. Mathematical morphology is a technique extensively used in the area of image processing, and it has been applied to calculating distance using the spread function. Unfortunately, its computation time is extremely long. In this paper, we propose to reduce the computation time by using a hierarchical data structure. The proposed approach and algorithm are presented and experimental results demonstrate that a substantial speed up in computation time can be obtained.
International Journal of Geographical Information Science 12(6), pp.515-535