[OSM-dev] Website to generate polygons from OSM relations

Jocelyn Jaubert jocelyn.jaubert at gmail.com
Tue Jun 11 21:45:31 UTC 2013


I have put into production a website to generate various outputs from
OSM relations, by taking into account inclusion of other relations. It
is available at:


What it can do:

 - generate whole geometry from an OSM relation ID, with handling of
sub-relations - this works especially well with the recursive French
model for administrative relations, and can be used as a sanity check.

 - generate simplified geometries, even bigger or smaller - this is
useful to cut a .osm file with a good .poly file.

 - export WKT, .poly, GeoJSON, or even a picture.

 - import a user .poly file, and then do an Union from an OSM relation.
I used this to fix some polygons used for Geofabrik extracts.

A few examples:

OSM relation for Corsica:


Same thing for France (image is a little longer to generate)

Union of Geofabrik and OSM relation for PACA, a french region:


(you can see that some part of the region were missing from the yellow

The source code is available at:

This uses an osmosis database, containing the whole word, and some
Postgis functions. If you have any suggestion, don't hesitate to propose
them !


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