Hi all, I was looking at the available OS data and one of the things they have but is not really in the current OSM database is building shapes. Individual buildings appear in the Street View data. The VectorMap District data seems to focus on land use and only has "important" buildings. The Street View data is much more complete in terms of individual buildings. I guess the questions we have to address are: "is this data worth having in OSM?" and "are there any better sources of building outline?" I think it would be a valuable addition for highly detailed mapping of urban areas, campuses, etc.
The other sources of building outlines I know of are the 1st edition OS sheets (which are rather old), Yahoo imagery (which takes work to trace), and manual surveying (which is a major hassle since buildings tend to throw off GPS positions). Another source would be preferable to these. If we do want this data, it seems to be only available as a raster layer. (Does anyone know if this will be available as a vector layer?) Converting raster map data to vector data is non trivial but I think it is achievable. The building colour in the raster map seems to be unique. The raster maps could be selected by colour, vectorised and simplified (to remove redundant nodes). Since we have a significant number of buildings mapped in the UK, we could presume that we don't want to overwrite or duplicate what is already there. Buildings could be imported if it would not overlap with an existing building in OSM. One problem is some buildings are marked as leisure=stadium without a building=*. We might end up with duplicates of stadiums, leisure centres, churches and so on. Would we want the import to be more cautious to prevent this? I won't be importing anything until the rectification of Street View is complete (and I get a feel for the consensus on the mailing list) but I have demoed most of the method in python using the shapely module to do some geometry transforms. Any general thoughts on buildings and imports? Will this data be officially available in vector form at some point? We don't seem to have much comment on the legal issues and the implications of ODbL yet. Do we have a view as to if our attribution is sufficient? Regards, TimSC _______________________________________________ Talk-GB mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-gb
