The application of volume M-type holograms for building multichannel geometries in pattern recognition systems is considered. The results of theoretical and experimental investigations of the hologram's parameters...
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ISBN:
(纸本)0819425818
The application of volume M-type holograms for building multichannel geometries in pattern recognition systems is considered. The results of theoretical and experimental investigations of the hologram's parameters as a function of their recording parameters and their use as filters in correlation setups are presented. Multichannel correlation schemes where the processed signals have either different or the same wavelength are proposed. We have shown that all the correlation schemes proposed allow one to increase data throughput several times over single-channel BR-based correlators.
Nonlinear joint transform correlators (JTCs) have been proposed for opticalinformationprocessing. They have been shown to be attractive in many difficult instances because of their high discriminating performance. H...
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ISBN:
(纸本)081942921X
Nonlinear joint transform correlators (JTCs) have been proposed for opticalinformationprocessing. They have been shown to be attractive in many difficult instances because of their high discriminating performance. However, unlike the linear matched filter, which was designed on the basis of the statistical estimation theory before its implementation in optical correlators, investigations on nonlinear filtering techniques have been mostly experimental and their basic properties in terms of signal processing and pattern recognition still need theoretical analyses. We propose in this paper to analyze the optimal solutions obtained in the context of the statistical estimation theory when the spectral density of the additive gaussian noise is unknown. Maximum likelihood, maximum a posteriori and Bayesian solutions to this problem are discussed and practical consequences are analyzed. In particular, we show that nonlinear JTC methods can be considered as a first order, but very efficient, approximation of these optimal solutions.
This paper describes algorithmic development toward an automated process that generates a same patient sequence of fundic images that are normalized in position and intensity and have noise artifacts removed. Normaliz...
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ISBN:
(纸本)0819425818
This paper describes algorithmic development toward an automated process that generates a same patient sequence of fundic images that are normalized in position and intensity and have noise artifacts removed. Normalization of these fundic images is a key first step to further automatic analysis for the presence or progress of ophthalmic diseases. The Litton PRC team, inclusive of Litton Data systems and Tomey Inc., evaluated the potential use of a hybrid optical/digital processor in the normalization of ophthalmic imagery. PRC provided the funding, initial architecture and approach for disease analysis using the optical processor. Tomey Inc. provided the fundus imagery and clinical advice on ''normalization'' of images prior to undertaking the disease analysis. Litton Data systems prototyped the algorithms and tests using a rapid application prototyping tool for object recognition. The team approach was to do a coarse vessel alignment to bring the images within a to-be-determined level of alignment, and then repeat the algorithms at a threshold and alignment for fine vessels. The success of the coarse work encouraged the investigation of algorithms for processing higher resolution images with greater accuracy. The combined results completed the IRAD investigation and are shown as successfully aligning two images.
We explain that a holographic filter of the generalized Hough transform can be easily obtained by the use of muliplexing techniques in hologram recording. To show the feasibility of our approach experimentally, we rec...
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ISBN:
(纸本)081942921X
We explain that a holographic filter of the generalized Hough transform can be easily obtained by the use of muliplexing techniques in hologram recording. To show the feasibility of our approach experimentally, we recorded the Hough transform filter of both line and circle parameterizations by combined use of rotational and angle multiplexing, Experimental results on the Hough transform for a few input patterns are presented.
In the Real World Computing Program, optics provides new device technology as well as new architectures and new algorithms, which aims at flexible informationprocessing by employing massively parallel and massively d...
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ISBN:
(纸本)0780314212
In the Real World Computing Program, optics provides new device technology as well as new architectures and new algorithms, which aims at flexible informationprocessing by employing massively parallel and massively distributed processing. Classified into three categories is optical technology to be developed in the program. These are namely, optical interconnection, optical neural systems, and optical digital systems.
The presence of turbulence such as maritime aerosols between the target and the observer degrades the detection and classification performance of electro-optical sensors and detectors. A filtering algorithm that takes...
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ISBN:
(纸本)081942921X
The presence of turbulence such as maritime aerosols between the target and the observer degrades the detection and classification performance of electro-optical sensors and detectors. A filtering algorithm that takes into account of the environmental degradation, the background non-overlapping noise, the non-stationarity of the scene, non-target objects and additive system noise is designed and implemented to detect and classify targets under such conditions. The detection performance of this algorithm has been validated using computer simulations and found to be superior to filters that are optimal with respect to noise statistics but do not take into account the effects of environmental conditions. The algorithm is then extended using a set of training images to be distortion-invariant with respect to different target aspects.
In this paper we present an optoelectronic hardware implementation of a neural network system based on optoelectronic devices and electronic techniques. The system is composed of basic cells with optoelectronic artifi...
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ISBN:
(纸本)0819445568
In this paper we present an optoelectronic hardware implementation of a neural network system based on optoelectronic devices and electronic techniques. The system is composed of basic cells with optoelectronic artificial neurons;every basic cells exploits the communication strengths of optics to broadcast the input to all neurons and the computational strengths of electronics to assign the interconnections weights. Description of the architecture of the basic cell, the first implementation of a prototype based on the proposed system and examples of configuration of the neural system are described.
Smart-pixel spatial light modulators (SLMs) with optical inputs and outputs can offer a powerful combination of optical and electronic processing functions. Here we report on work in progress on an experimental FLC-VL...
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ISBN:
(纸本)081942921X
Smart-pixel spatial light modulators (SLMs) with optical inputs and outputs can offer a powerful combination of optical and electronic processing functions. Here we report on work in progress on an experimental FLC-VLSI SLM intended for use in the first Fourier plane of a joint transform correlator (JTC). The JTC SLM is designed to eliminate the unwanted autocorrelation term that normally exists in the JTC's output. One of the JTC's input images is modulated in phase or amplitude causing a modulation term to occur in the intensity of their joint transform. The smart-pixel SLM selectively responds to the modulation term and displays the result as an image that will pass through the second and final Fourier transform lens (each pixel contains both a photodetector and an optical modulator).
The search for a dynamic recording medium that can be used in real time without the need for processing has become a critical issue in the development of practical neural network systems, correlators, all-optic switch...
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ISBN:
(纸本)0819425818
The search for a dynamic recording medium that can be used in real time without the need for processing has become a critical issue in the development of practical neural network systems, correlators, all-optic switches, image and signal processors, and optical storage (including 3-D) devices. A typical optical material responds to changes in the intensity, polarization, or wavelength of the illuminating light. The optical material developed and used for neural network applications responds to changes in the polarization of blue or green laser (Ar+) light. Implementing a neural network or performing optically-controlled acoustic beam steering requires a high-speed read/write/erase optical memory. POC's erasable dye polymer (EDP) material offers a high read/write/erase data rate, nondestructive reading, fast data access, high storage density, overwrite capability, and long cycle life.
An encrypted holographic memory based on double random phase encoding and angular multiplexing is presented. A two-dimensional digital image is encrypted by two random phase codes located at the input and Fourier plan...
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ISBN:
(纸本)0819432903
An encrypted holographic memory based on double random phase encoding and angular multiplexing is presented. A two-dimensional digital image is encrypted by two random phase codes located at the input and Fourier planes. The input digital image is displayed on a liquid crystal display. In a photorefractive LiNbO3:Fe crystal, Fourier-transformed patterns of encrypted images are stored holographically by using angular multiplexing. Experimental results of encryption and decryption of digital data ate presented.
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