UNSUPERVISED FILTERING OF COLOR SPECTRA

Citation
R. Lenz et al., UNSUPERVISED FILTERING OF COLOR SPECTRA, Journal of the Optical Society of America. A, Optics, image science,and vision., 13(7), 1996, pp. 1315-1324
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Optics
ISSN journal
1084-7529
Volume
13
Issue
7
Year of publication
1996
Pages
1315 - 1324
Database
ISI
SICI code
1084-7529(1996)13:7<1315:UFOCS>2.0.ZU;2-4
Abstract
We describe a class of unsupervised systems that extract features from databases of reflectance spectra that sample color space in a way tha t reflects the properties of human color perception. The systems find the internal weight coefficients by optimizing an energy function. We describe several energy functions based on second- and fourth-order st atistical moments of the computed output values. We also investigate t he effects of imposing boundary conditions on the filter coefficients and the performance of the resulting systems for the databases with th e reflectance spectra. The experiments show that the weight matrix for one of the systems is very similar to the eigenvector system, whereas the second type of system tries to rotate the eigenvector system in s uch a way that the resulting filters partition the spectrum into diffe rent bands. We also show how the system can be forced to use weight ve ctors with positive coefficients. Systems consisting of positive weigh t vectors are then approximated with Gaussian quadrature methods. In t he experimental part of the paper we investigate the properties of thr ee databases consisting of reflectance spectra. We compare the statist ical structure of the different databases and investigate how these sy stems can be used to explore the structure of the space of reflectance spectra. (C) 1996 Optical Society of America