[OSM-dev] OSM based replacement for builtup_area.shp in standard style

[Christoph Hormann]

Hello Everyone,

it has been pointed out occasionally (see for example [1]) that current 
use of external data sources in the OSM standard style is somewhat 
ugly.

Back in April i made some tests how to process OSM data to generate 
simplified polygons for urban landuse/builtup areas to be used as 
replacement for builtup_area.shp (which is the most significant outside 
source currently in the standard style).  This has not been mentioned 
here, you can read the details on [2].  I have now improved this 
technique sufficiently to process the whole planet and you can find a 
shapefile for testing on [3].

This is of course a fairly ressource intensive process with all building 
and road data in the database being used as basis.  But in principle it 
would be possible to run this with periodic updates in a similar way as 
currently done for the coastline.

Everyone feel free to try out these polygons in your maps.  I have not 
tried this myself in the standard style yet, it is likely that 
adaptations in either the generalization process or the style (or both) 
are necessary for best results.  Comments and examples on that are 
welcome.

Greetings,

Christoph

[1] http://wiki.openstreetmap.org/wiki/User:Mrwojo/builtup_area.shp
[2] http://www.imagico.de/map/osm_builtup_en.php
[3] http://www.imagico.de/map/osm_builtup_en.php#download

-- 
Christoph Hormann
http://www.imagico.de/