[OSM-talk-be] Comparison between OSM buildings and Urbis buildings

[Marc Ducobu]

Hello,

Every 3 months, the layer UrbAdm of Urbis is updated and we do not
have an automatic way to know what to update in OSM. So I tried some
experiments and I write an article about it :
http://blog.champs-libres.coop/carto/2015/12/01/comparaison-urbis-osm.html

As the article is in French, here is a quick explanation in En :
- the OSM data & Urbis data are loaded in a PostGIS database
- for the moment only one type of polygons that are different in Urbis
& OSM are detected :
 - polygons such that :
      - there is an intersection between the osm polygon and the urbis polygon
      - the Hausdorff distance between the osm polygon and the urbis
polygon is greater than 0.0015 (
https://en.wikipedia.org/wiki/Hausdorff_distance )

Theses polygons are there :
https://cloud.champs-libres.coop/index.php/s/GpGVahe6wMCtPNn

The method can easily improved to detect polygons that are in urbis
and not is OSM (and vice-versa). But there is some work to perform to
detect more precisely the difference and also for dealing with
multi-polygons

Marc