Abstract

An optical associative memory is implemented by using orthogonal features extracted through an optical wavelet transformation of a modified Peano scan of a 2-D image. The wavelet transform of 2-D data requires 4-D data representation. This is difficult to perform. By using a modified Peano scan it is possible to reduce the 2-D data to a 1-D vector, thus decreasing subsequent processing to 2-D while preserving much of the proximity relationships. The capacity of associative memories for pseudo-orthogonal vectors is typically about 13% of the total number of neurons. However, this capacity can be increased by using an optical wavelet transformation to extract orthogonal features to be used as input to the optical associative memory. The wavelet functions are typically stored within a fixed medium, producing a static optical storage matrix. By using a dynamically erasable optically addressable storage medium, such as an organic photopolymer, a dynamically reconfigurable storage matrix for wavelet functions is demonstrated.

© 1992 Optical Society of America