Chaitanya thanks for the hints. So a sort of Union operation seems to be necessary. I need to check how fast that is with OGR on larger shapefiles (I want to store in PostGIS just the footprint, not the full geometry collection). The ConvexHull could be a good alternative to a simplified boundary.
I understand how the normal Union() works, it merges 2 geometries into a new one. But I don't get it what UnionCascade() is doing. It applies a Union on a single geometry and returns the new geometry, what is it actually unioning/merging then? Regards, Armin -------- Original-Nachricht -------- > Datum: Wed, 16 Mar 2011 10:06:57 +0530 > Von: Chaitanya kumar CH <chaitanya...@gmail.com> > An: armin.bur...@gmx.net > CC: Marius Jigmond <mariusjigm...@hotmail.com>, gdal-dev@lists.osgeo.org > Betreff: Re: [gdal-dev] Calculate footprints of shapefiles > Armin, > > This can be done in either OGR or PostGIS. > > For OGR, refer to the OGRGeometry class reference, especially the > ConvexHull(), Union() and UnionCascaded() functions. > For PostGIS, ST_Boundary() and ST_Union(). > -- GMX DSL Doppel-Flat ab 19,99 Euro/mtl.! Jetzt mit gratis Handy-Flat! http://portal.gmx.net/de/go/dsl _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
