Hi all, I am looking for a method that generates me an enclosing polygon that should contain all input geometries but is not as big as the polygon generated by the ST_ConvexHull() command. The input should be a list of different geometries (point,linestring,polygon), and the output should be one polygon that can contain concave outlines but needs to guarantee that all input geometries are inside. I don't know if any term exists for such a polygon. Concave-hull? Non-convex hull?
Googling around I came across: http://www.spatialanalysisonline.com/output/html/Non-convexhulls.html >From the figure, version "d" is actually what I want as a result. Or here is another pointer: http://ubicomp.algoritmi.uminho.pt/local/concavehull.html My question now: Are there existing methods in Postgis or geos that would help me generate such polygons? If not - how many hours would a Postgis programmer potentially need to implement such an algorithm in Postgis? Thanks, Andreas -- Andreas Neumann http://www.carto.net/neumann/ http://www.svgopen.org/ _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users