ABSTRACT
Optical information processing techniques based in the operation of correlation have proved to be a real alternative to electronic processing in applications such as security, encryption, and pattern recognition [1-12]. Optical techniques provide parallel operation, a high space-bandwidth product, and a large degree of freedom to secure data. These advantages, together with recent advances in electro-optical devices and components, have contributed to the progression of optical correlation methods. However, many of the reported techniques are based in the ability of a lens to perform optically a two-dimensional (2D) Fourier transform operation. Thus, optical pattern recognition technqiues have been commonly restricted to 2D input images.
