Optical implementation of a feature-based neural network with application to automatic target recognition

Parallel optical-feature extraction by use of rotationally multiplexed holograms

We propose a novel rotational (peristrophic) multiplexing method of hologram recording for parallel opticalfeature extraction and report basic experimental results. The features to be extracted are line-segment orientations separated by 30 degrees . The extracted features can be used for f lexible pattern recognition.

Multilayer associative memory and its hybrid optical implementation

We propose a multilayer associative memory with a winner-take-all operation on the inner product between an input and stored exemplars. The winner-take-all operation is performed by a unit-step operation with an adaptive-threshold strategy. We show that the multilayer-associative-memory unit-step operation with an adaptive-threshold strategy has a high noise immunity and a large storage capacity, and it is also capable of extending to a gray-level associative memory with a phase-representation technique. A hybrid optical implementation with a proof-of-concept experiment is also provided.

Nonlinear optical hit-miss transform for detection

Morphological processing involves nonlinear low-level image-processing operations that can be realized on optical processors. Amodified version of the hit-miss morphological transform is described for object detection. Simulation results and optical laboratory realizations are presented. Some of the simple filters required can be realized as ternary-phase-amplitude optical filters.