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Similarity Metric Learning for a Variable-Kernel Classifier

David G. Lowe
Computer Science Department
University of British Columbia
Vancouver, B.C., V6T 1Z4, Canada
E-mail: lowe@cs.ubc.ca

Abstract:

Nearest-neighbour interpolation algorithms have many useful properties for applications to learning, but they often exhibit poor generalization. In this paper, it is shown that much better generalization can be obtained by using a variable interpolation kernel in combination with conjugate gradient optimization of the similarity metric and kernel size. The resulting method is called variable-kernel similarity metric (VSM) learning. It has been tested on several standard classification data sets, and on these problems it shows better generalization than back propagation and most other learning methods. An important advantage is that the system can operate as a black box in which no model minimization parameters need to be experimentally set by the user. The number of parameters that must be determined through optimization are orders of magnitude less than for back-propagation or RBF networks, which may indicate that the method better captures the essential degrees of variation in learning. Other features of VSM learning are discussed that make it relevant to models for biological learning in the brain.

UBC-TR-93-43. This paper will be published in Neural Computation.





accesses since October 4, 1996.

David G. Lowe
Mon Mar 18 12:36:07 PST 1996