Sumit Chopra Raia Hadsell Yann LeCun Learning a Similarity Metric Discriminatively, with Application to Face Verification. 539-546 2005 conf/cvpr/2005 CVPR (1) http://dx.doi.org/10.1109/CVPR.2005.202 db/conf/cvpr/cvpr2005-1.html#ChopraHL05