M. Barge et al., 64-CHANNEL CORRELATOR IMPLEMENTING A KOHONEN-LIKE NEURAL-NETWORK FOR HANDWRITTEN-DIGIT RECOGNITION, Applied optics, 35(23), 1996, pp. 4655-4665
We present an optical implementation of an improved version of the Koh
onen map neural network applied to the recognition of handwritten digi
ts taken from a postal code database. Improvements result from the int
roduction of supervision during the learning stage, a technique that a
lso simplifies the map layer labeling. The experimental implementation
is based on a frequency-multiplexed raster computer-generated hologra
m used to realize the required N-4 interconnection. The setup is shown
to be equivalent to a 64-channel correlator. Computer simulations are
used to study various detection and classification procedures. The re
sults of the optical experiments, obtained with binary phase computer
generated holograms, are presented and shown to be in excellent agreem
ent with the simulations. (C) 1996 Optical Society of America