Hi, I have performed a test import of a fragment of auto-traced building outlines data for Szczecin, Poland and am looking for comments before continuing with the rest of the city and perhaps other cities, http://osm.org/go/0NgiAGiak--. This contains addresses, heights (in storeys count) and primary usage for each building. I made an analogy to French cadastre because this data is based on the city's website running a map server that only provides raster images and is auto-traced using a program, I'm not sure if this has been done before but the result is similar to the manual tracing.
The full story: In Wroclaw, Poland user "lms" asked the city administration if he could use their 8cm aerial imagery for tracing map features for OSM to which the city responded that he was permitted to use all of their website, which also has about 10 other data layers accessible through the web interface. With lots of hard work he has traced many buildings in his district with similar tools and similar results to the French cadastre users in OSM. Later user "antblant" obtained a similar permit with regards to the Szczecin city's GIS website (gis.um.szczecin.pl). Since both websites let you zoom in as much as you like on the data layers, you can in theory reproduce the full vector layer, either manually or using some smart algorithm. I have asked the mappers to also ask the city councils if they allowed automatic tracing of the features from their data layers and so far the Szczecin point of contact has replied that they had nothing against automatic tracing and indeed were interested in knowing how this worked. I'm using a modified potrace (subproject of Inkscape I think?) as the "brain" of a python script that later spends 10 times longer than potrace in fixing the result of the tracing to get usable quality and I'm quite happy with the results now. It still requires manual fixes here and there, but there's some space for improvement in the script still. The housenumbers and heights are obtained from different layers. I have also asked my city's (Warsaw) "geodesy and cadastre bureau" the same question about using their website but they're much less willing to allow any use under any free license and I have heard at least two different answers so far, maybe that's because I'm talking to a contact person there who is not a lawyer and has to go and ask their lawyer about every detail and I have even heard complaints from him about the lawyer guy's attitude and how it isn't easy to catch him at work much less ask him something. One thing he made clear is that there's some law that prevents the cities in Poland from releasing the actual vector data to anyone under any license allowing redistribution or commercial use, and even for private use the access to the building outlines for all of Warsaw for example costs about EUR 75000 and this is also fixed by that law... :( Cheers _______________________________________________ Imports mailing list Imports@openstreetmap.org http://lists.openstreetmap.org/listinfo/imports
