Competitive learning and winning-weighted competition for optimal vector quantizer design

Abstract

It is essential to build a nonparametric model to estimate a probability density function p(x) in the areas of vector quantization, pattern recognition, control, and many others. A generalization of Kohonen learning, the winning-weighted competitive learning (WWCL), is presented for a better approximation of p(x) and fast learning convergence by introducing the principle of maximum information preservation into the learning. The WWCL is a promising alternative and improvement to the generalized Lloyd algorithm (GLA) which is an iterative descent algorithm with a monotonically decreasing distortion function towards a local minimum. The WWCL is an online algorithm where the codebook is designed while training data is arriving and the reduction of the distortion function is not necessarily monotonic. Experimental results show that the WWCL consistently provides better codebooks than the Kohonen learning and the GLA in distortion or convergence rate. >