Ville Viitaniemi Jorma Laaksonen Representing Images with <i>chi</i><sup>2</sup> Distance Based Histograms of SIFT Descriptors. 694-703 2009 ICANN (2) http://dx.doi.org/10.1007/978-3-642-04277-5_70 conf/icann/2009-2 db/conf/icann/icann2009-2.html#ViitaniemiL09