Topological Consistent Generalization of OpenStreetMap

Abstract included in text

Topological Consistent Generalization of OpenStreetMap

Abstract included in text

A Robust Strategy for Handling Linear Features in Topologically Consistent Polyline Simplification

Polyline simplification is a technique that reduces the number of vertices of a polygonal chain for the purpose of map generalization and for speeding up processing and visualization in GIS. Unfortunately, the majority of simplification algorithms does not preserve the topological consistency of the map, namely the spatial placement of a polyline with respect to itself and to its neighbouring features. To overcome this problem, some approaches based on the consistency of a point feature have been proposed. For the sake of simplicity, they unify the handling of linear and point features by considering a linear feature as a sequence of point features. This solution, however, fails in a few particular cases. In this paper, we firstly examine the reason for it to fail and then present a robust strategy for remedying the remaining problems without abandoning the basic principle of reducing a linear feature to a sequence of point features.Pages: 19-3

A Robust Strategy For Handling Linear Features In Topologically Consistent Polyline Simplification

Polyline simplification is a technique that reduces the number of vertices of a polygonal chain for the purpose of map generalization and for speeding up processing and visualization in GIS. Unfortunately, the majority of simplification algorithms does not preserve the topological consistency of the map, namely the spatial placement of a polyline with respect to itself and to its neighbouring features. To overcome this problem, some approaches based on the consistency of a point feature have been proposed. For the sake of simplicity, they unify the handling of linear and point features by considering a linear feature as a sequence of point features. This solution, however, fails in a few particular cases. In this paper, we firstly examine the reason for it to fail and then present a robust strategy for remedying the remaining problems without abandoning the basic principle of reducing a linear feature to a sequence of point features.Ai, T., Guo, R., Liu, Y., Safe sets for line simplification (2000) The 9th International Symposium on Spatial Data Handling, pp. 30-43De Berg, M., Van Kreveld, M., Schirra, S., Topologically correct subdivision simplification using the bandwidth criterion (1998) Cartography and Geographic Information Systems, 25 (4), pp. 243-257Douglas, D.H., Peucker, T.K., Algorithms for the reduction of the number of points required for represent a digitized line or its caricature (1973) Canadian Cartographer, 10 (2), pp. 112-122Edwardes, A., MacKaness, W., Urvin, T., Self evaluating generalization algorithms to automatically derive multi scale boundary sets (1998) The 8th International Symposium on Spatial Data Handling, pp. 361-372. , Vancouver, CanadaJenks, G.F., Lines, computers and human frailties (1981) Annals of the Association of American Geographers, 71, pp. 1-10Jones, C.-B., Bundy, G.-L., Ware, J.-M., Map generalization with a triangulated data structure (1995) Cartography and Geographic Information Systems, 22 (4), pp. 317-331Lang, T., Rules for the robot draughtsmen (1969) The GeographicalMagazine, 42 (1), pp. 50-51McKeown, D., McMahill, J., Caldwell, D., The use of spatial context in linear feature simplification (1999) GeoComputation 99, , Mary Washington College, Fredericksburg, VirginiaMüller, J.C., The removal of spatial conflicts in line generalisation (1990) Cartography and Geographic Information Systems, 17 (2), pp. 141-149Ramer, U., An iterative procedure for the polygonal approximation of plane curves (1972) Computer Graphics and Image Processing, 1, pp. 224-256Reumann, K., Witkam, A.P.M., Optimizing curve segmentation in computer graphics (1974) Proceedings of the International Computing Symposium, pp. 467-472. , Gunther, A., Levrat, B., and Lipps, H., editors,. American ElsevierSaalfeld, A., Topologically consistent line simplification with the Douglas-Peucker algorithm (1999) Cartography and Geographic Information Science, 26 (1), pp. 7-18Tobler, W.R., (1964) An Experiment in the Computer Generalization of Map, , Technical report, Office of Naval Research, Geography BranchVan Der Poorten, P., Jones, C., (1999) Customisable Line Generalisation Using Delaunay Triangulation, , The 19th International Cartographic Association ConferenceVan Der Poorten, P., Jones, C., Characterisation and generalisation of cartographic lines using Delaunay triangulation (2002) International Journal of Geographical Information Science, 16 (8), pp. 773-795Visvalingam, M., Whyatt, J.D., Line generalisation by repeated elimination of points (1993) Cartographic Journal, 30 (1), pp. 46-51Wang, Z., Müller, J.C., Line generalization based on analysis of shape characteristics (1998) Cartography and Geographic Information Systems, 22 (4), pp. 264-27

Proceedings of the GIS Research UK 18th Annual Conference GISRUK 2010

This volume holds the papers from the 18th annual GIS Research UK (GISRUK). This year the conference, hosted at University College London (UCL), from Wednesday 14 to Friday 16 April 2010. The conference covered the areas of core geographic information science research as well as applications domains such as crime and health and technological developments in LBS and the geoweb. UCL’s research mission as a global university is based around a series of Grand Challenges that affect us all, and these were accommodated in GISRUK 2010. The overarching theme this year was “Global Challenges”, with specific focus on the following themes: * Crime and Place * Environmental Change * Intelligent Transport * Public Health and Epidemiology * Simulation and Modelling * London as a global city * The geoweb and neo-geography * Open GIS and Volunteered Geographic Information * Human-Computer Interaction and GIS Traditionally, GISRUK has provided a platform for early career researchers as well as those with a significant track record of achievement in the area. As such, the conference provides a welcome blend of innovative thinking and mature reflection. GISRUK is the premier academic GIS conference in the UK and we are keen to maintain its outstanding record of achievement in developing GIS in the UK and beyond