Topology-preserving automated cartographic generalisation: Polygon simplification, error correction and measuring performance

Abstract

Location-based services and mobile applications that use cartographic data are becoming increasingly popular. When serving mobile clients with map data across a network it is important to minimise the data to be transferred. A vector-based data representation together with employing cartographic map generalisation to produce multiple maps of the same area at decreasing level of detail serves this goal. This paper presents core concepts in map-based applications and map generalisation. The theory of map generalisation and the state of the art algorithms in that field are explained, with a focus on preserving the topological relationships between map objects. The SmoothShp map generalisation algorithm is conveyed and discussed. A method for measuring the effect of map generalisation in a complete system for location-based services with web and mobile phone clients is presented, measurements are carried out and the results discussed.