>Aren't these polygons just vast derivative works of either OSM or >TeleAtlas/NavTeq data? Possibly, but I don't think so. ANAL disclaimer etc.
>All those geocoded photos that were just placed >on a map... derive the places from the map, right? nope - Yahoo's geo database was not made from flickr photos. For the Flickr example, the situation is not quite as pictured: Flickr uses dataset of WOEs. (we imagine it can be visualised as having polygons) A user adds and geotags a photo, using whatever they want, osm, exif, drag and drop. Flickr works out which WOE the photo is in. (point in polygon stuff) Flickr then uses clustr to make shapefiles based on the photos tagged with the WOE id. So, you will never get these new shapes with a larger extent than the real WOE dataset's polygon, but if no one has geotagged any images in a part of that WOE area, then it will be reflected in the clustr shapefile. ( Which could be an interesting analysis in itself, why don't people want to take pictures in my neighbourhood?) Flickr releases these new shapefiles. It's all a bit circular. So, these shapefiles are mainly a re-jigging of the WOE dataset. Actually how, or what dataset they use to add their photo's is less important, as they only really need to fall into a WOE bin to be counted. _______________________________________________ Geowanking mailing list [email protected] http://geowanking.org/mailman/listinfo/geowanking_geowanking.org
