Intersection and Union Overlays for GIS

Abstract

Intersection and Union are the most important Overlay functions in the GIS. It mainly concerns with the algorithms which should be optimized and made efficient in terms of memory requirement and processor utilization. Memory can be saved by using the simple data structure and processor utilization can be improved by using algorithms which minimizes the use of more iterative loops. This thesis explains efficient algorithms related to the Intersection and Union overlay and is based on the vector images mainly stored as shape file format. Intersection and Union algorithms mainly concerns with the Point in Polygon strategies, Line-Line intersection, Line-Polygon intersection, Polygon- Polygon intersection, Polygon-Polygon Union and their integration with each other. By using this algorithms Intersection and Union Overlays can be developed using different programming languages. Here it is developed using VC++ and VB.