Abstract: A request may be received that includes an indicator associated with a geographic location and scope. A database search may be initiated, based on the geographic location and scope. A list of one or more tags may be received, the tags associated with the geographic location, ordered based on relevance within the geographic scope, based on tag locale rankings associated with each of the tags included in the list of tags, the tag locale rankings based on comparisons of relative frequencies of occurrence of the tags, based on first bounded geographic areas, compared with second relative frequencies of occurrence of the tags based on second bounded geographic areas that are respectively larger than the first bounded geographic areas, the request geographic scope indicating one of a plurality of hierarchical geographic analysis levels associated with a plurality of geographic locations.

Abstract: An image matching system is described for finding reference images which match a query image. The image matching system performs this operation in expeditious fashion by restricting the matching to a bounding region; the bounding region, in turn, may be associated with a location at which the query image may have been captured. In addition, the image matching system provides various mechanisms that expedite adding new reference images to an image index, to thereby provide a re-enforced learning mechanism of the image matching system.