Michael Grubinger Paul Clough Allan Hanbury Henning Müller Overview of the ImageCLEFphoto 2007 Photographic Retrieval Task. 433-444 2007 CLEF http://dx.doi.org/10.1007/978-3-540-85760-0_57 conf/clef/2007 db/conf/clef/clef2007.html#GrubingerCHM07