Results 161 to 170 of about 586,449 (202)
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Optical image segmentation using wavelet correlation
SPIE Proceedings, 1992This research introduces an optical method of segmenting potential targets using wavelet analysis. An optical Harr wavelet is created using a magneto-optic spatial light modulator (MOSLM). Two methods of controlling wavelet dilation are explored: (1) an aperture positioned in front of a binary modulated MOSLM; (2) spatial filtering of a ternary ...
Steven D. Pinski +7 more
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Optical image plane correlator for ambiguity surface computation
Applied Optics, 1979An optical image plane correlator is described which computes the ambiguity function for passive, wideband, complex, and basebanded signals. Quadrature input modulation, single-sideband filtering, and a modified image plane correlator requiring no moving parts are used to achieve the required complex correlations.
D, Casasent, B V, Kumar
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Hilbert transform and mirror-image optical correlators
Applied Optics, 2000An optical correlator, believed to be novel, adds an x-y mirror image to the input and filter images to perform convolution involving amplitude and phase. The resulting real Fourier transform filters can be loaded into a liquid-crystal device (LCD). In contrast, a complex filter would require high-resolution film. A Hilbert transform and a point source
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3D image correlator using optically reconstructed integral plane images
SPIE Proceedings, 2009ABSTRACT In this paper, we propose an optical method for 3-D image correlator using reconstructed integral plane images. In the proposed correlator based on integral imaging, elemental imag es of the reference and signal 3-D objects are recorded by lenslet arrays and then reference and signal integral plane images are optically reconstructed on the ...
Yong-Ri Piao +3 more
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Adaptive Optical Target Detection Using Correlated Images
IEEE Transactions on Aerospace and Electronic Systems, 1985A method for target detection that achieves clutter rejection by the use of multiple observations of the same target scene is developed. Multiple scene observations can be obtained by processing separate frequency bands of the same target scene or by recursively processing sequential observations in time.
A. Margalit, I.S. Reed, R.M. Gagliardi
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A Hybrid Optical/Electronic Image Correlator
1987The attraction of using optics to perform the cross-correlation of two images, is the ease with which a good quality lens generates a 2-D Fourier transform. This Fourier transform property of the lens is dependent on the use of coherent light to carry the image.
N. Collings +3 more
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Compact real-time acousto-optic image correlator
SPIE Proceedings, 1990The design and development of a compact acousto-optic image correlator capable of performing real-time correlations on grayscale imagery will be described. The system utilizes one-dimensional optical devices to perform the desired two-dimensional correlation.
Perry A. Molley +2 more
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Multichannel correlation recognition method of optical images
SPIE Proceedings, 2000In this paper a multi-channel real-time hybrid joint transform correlator is proposed. In this correlator, the computer control is used to divide the screen into several equal size windows, reference images of the windows are all the same one and object images are adopted from different frames of image sequences by CCD, twice Fourier transforms of ...
Hongxia Wang, Junfa He, Honghui Sun
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Optimization Of An Updatable Optical Image Correlator
Optical Engineering, 1987The utility of updatable optical image correlation in photorefractive materials for industrial applications is discussed. This allows the formation of iterative correlation products employing variable spatial frequency weighting and/or different reference images.
M. G. Nicholson +3 more
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Towards A Practical Updatable Optical Image Correlator
SPIE Proceedings, 1987We describe initial experiments on a photorefractive based optical image correlator which employs a frequency doubled, pulsed Nd:YAG laser with a pulse length of 10 nsec to write a phase grating into a crystal of bismuth silicon oxide. The correlation of simple binary images has been demonstrated and measurements indicate that the rise time of the ...
M. G. Nicholson +2 more
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