LATERALLY INTERCONNECTED SELF-ORGANIZING FEATURE MAP IN HANDWRITTEN DIGIT RECOGNITION

Yoonsuck Choe and Risto Miikkulainen
Under Construction

Abstract

An application of biologically motivated laterally interconnected synergetically self-organizing maps (LISSOM) to off-line recognition of handwritten digit is presented. The lateral connections of the LISSOM map learns the correlation between units through Hebbian learning. As a result, the excitatory connections focus the activity in local patches and lateral connections decorrelate redundant activity on the map. This process forms internal representations for the input that are easier to recognize than the input bitmaps themselves or the activation patterns on a standard Self-Organizing Map (SOM). The recognition rate on a publically available subset of NIST special database 3 with LISSOM is 4.0% higher than that based on SOM, and 15.8% higher than that based on raw input bitmaps. These results form a promising starting point for building pattern recognition systems with a LISSOM map as a front end.

(a)Input Samples
(b)Initial Response
(c)Settling
(d)Final Response
(e)Scale
Figure 1: The settling of map activity through repeated, recursive lateral interaction with digits 5 (upper row) and 8 (lower row) are shown. (a) The two input samples, 5 and 8. (b) The initial response of the map shows wide spread and unfocused activity. (c) The animation shows the settling of the map activity through recursive lateral interaction. (d)The final response of the map after 15 settling iterations shows focused and sharp activity. Also, it is notable that the initial response of the map to the two different digits 5 and 8 are similar, the settled activity becomes distinct from each other.(e) The color scale codes the activity from 0.0 (black) through 1.0 (white).

Related Publications

  1. Yoonsuck Choe, Joseph Sirosh, and Risto Miikkulainen. "Laterally Interconnected Self-Organizing Maps in Hand-Written Digit Recognition" , To appear in D.S.Touretzky, M.C.Mozer, and M.E.Hasselmo. (Editors), Advances in Neural Information Processing Systems 8, pages 736-742. MIT Press, Cambridge, MA, 1996.
  2. Yoonsuck Choe. "Laterally Interconnected Self-Organizing Feature Map in Handwritten Digit Recognition", Techical Report AI95-236, Department of Computer Sciences, University of Texas at Austin, August 1995 [Masters Thesis]


This page is maintained by Yoonsuck Choe (yschoe@cs.utexas.edu).
Last Updated : Mon Sep 29 03:54:46 CDT 1997

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