Geoinformatica DOI 10.1007/s10707-013-0199-6 Large-scale geo-tagged video indexing and queries He Ma · Sakire Arslan Ay · Roger Zimmermann · Seon Ho Kim Received: 14 December 2012 / Revised: 8 August 2013 / Accepted: 28 November 2013 © Springer Science+Business Media New York 2013 Abstract With the wide spread of smartphones, a large number of user-generated videos are produced everyday. The embedded sensors, e.g., GPS and the digital compass, make it possible that videos are accessed based on their geo-properties. In our previous work, we have created a framework for integrated, sensor-rich video acquisition (with one instanti- ation implemented in the form of smartphone applications) which associates a continuous stream of location and viewing direction information with the collected videos, hence allowing them to be expressed and manipulated as spatio-temporal objects. These sensor meta-data are considerably smaller in size compared to the visual content and are helpful in effectively and efficiently searching for geo-tagged videos in large-scale repositories. In this study, we propose a novel three-level grid-based index structure and introduce a num- ber of related query types, including typical spatial queries and ones based on bounded radius and viewing direction restriction. These two criteria are important in many video applications and we demonstrate the importance with a real-world dataset. Moreover, exper- imental results on a large-scale synthetic dataset show that our approach can provide a H. Ma () · R. Zimmermann School of Computing, National University of Singapore, Singapore 117417, Singapore e-mail: mahe@comp.nus.edu.sg; he.ma@nusri.cn R. Zimmermann e-mail: rogerz@comp.nus.edu.sg S. Arslan Ay School of Electrical Engineering & Computer Science, Washington State University, 355 Spokane St. Pullman, Washington, DC 99164-2752, USA e-mail: sakire.arslanay@wsu.edu S. H. Kim Integrated Media Systems Center, University of Southern California, Los Angeles, CA 90089, USA e-mail: seonkim@usc.edu H. Ma Center of Interactive Media and Software Development, National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Jiang Su 215123, People’s Republic of China