Audio and video cues for geo-tagging online videos in the absence of metadata

Tagging videos with the geo-coordinates of the place where they were filmed (i.e. geo-tagging) enables indexing online multimedia repositories using geographical criteria. However, millions of non geo-tagged videos available online are invisible to the eyes of geo-oriented applications, which calls for the development of automatic techniques for estimating the location where a video was filmed. The most successful approaches to this problem largely rely on exploiting the textual metadata associated to the video, but it is not rare to encounter videos with no title, description nor tags. This work focuses on this adverse scenario and proposes a purely audiovisual approach to geo-tagging. Using a subset of the MediaEval 2011 Placing task data set, we evaluate the ability of several visual and acoustic features for estimating the videos location, and demonstrate that the optimally configured version of the proposed system outperforms the only audiovisual participant in the MediaEval 2011 Placing task.