Tim, I think this is a really good idea, and is one of the main benefits of the StreetView data.
I have been wondering how to do this, but haven't got far. I would like to see a plugin for josm that takes a raster input (landsat, yahoo, StreetView) and processes it into 'draft' ways around areas of constant(ish) colour - the user then tidies it up and tags it before uploading (ie I would be very wary of a 'blind' import!). I think streetview would be the easiest because of the high contrast - I would like to see it work for landsat because I am colourblind and can't trace the outline of woods, and the North Yorkshire moors need some more detail!. Someone (I think it was Mike DuPont) reported doing this with gdal_contour, but I haven't tried it yet, and I haven't looked at how to turn this into a josm plugin. If I'd thought of it earlier I would have suggested this as a GSoC student project! Regards Graham. On 5 April 2010 17:57, TimSC <mapp...@sheerman-chase.org.uk> wrote: > > 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 > Talk-GB@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-gb > -- Dr. Graham Jones Hartlepool, UK email: grahamjones...@gmail.com
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