Identification of Scene Locations from Geotagged Images

摘要

Due to geotagging capabilities of consumer cameras, it has become easy to capture the exact geometric location where a picture is taken. However, the location is not the whereabouts of the scene taken by the photographer but the whereabouts of the photographer himself. To determine the actual location of an object seen in a photo some sophisticated and tiresome steps are required on a special camera rig, which are generally not available in common digital cameras. This article proposes a novel method to determine the geometric location corresponding to a specific image pixel. A new technique of stereo triangulation is introduced to compute the relative depth of a pixel position. Geographical metadata embedded in images are utilized to convert relative depths to absolute coordinates. When a geographic database is available we can also infer the semantically meaningful description of a scene object from where the specified pixel is projected onto the photo. Experimental results demonstrate the effectiveness of the proposed approach in accurately identifying actual locations.