David W. Jacobs Daphna Weinshall Yoram Gdalyahu Classification with Nonmetric Distances: Image Retrieval and Class Representation. 583-600 2000 22 IEEE Trans. Pattern Anal. Mach. Intell. 6 http://www.computer.org/tpami/tp2000/i0583abs.htm db/journals/pami/pami22.html#JacobsWG00