Results 251 to 260 of about 16,724,170 (299)

Miniature acousto-optic image correlator

SPIE Proceedings, 1991
An acousto-optic (AO) image correlator architecture will be presented that minimizes the overall system size while maintaining excellent image quality for large input scenes. The correlator can accommodate gray-scale input scenes with dimensions of 512 X 244 pixels and gray-scale reference templates of 64 X 64 pixels.
Perry A. Molley, William C. Sweatt, David S. Strong   +2 more
openaire   +1 more source

Image Velocity Sensing by Optical Correlation

Applied Optics, 1966
The technique of measuring the velocity of a moving image by means of a parallel-slit spatial filter is treated as continuous optical correlation processing. This technique is compared with other approaches to measuring image velocity by correlation and is shown to be a special case where the image displacement necessary for the correlation measurement
openaire   +2 more sources

Optical correlator based on the Hilbert transform for image recognition

2021 13th International Conference on Electronics, Computers and Artificial Intelligence (ECAI), 2021
In this paper, we evaluated the advantages of using the Hilbert transform in an optical correlator. We reviewed state-of-art optical techniques that employ the Hilbert transform and, based on the principle of the classic Hilbert correlator, we performed simulations for this type of optical correlator.
Andrei Dragulinescu, Ana-Maria Dragulinescu, Ioana M. Marcu   +2 more
openaire   +2 more sources

Multisensor image registration and optical correlation

SPIE Proceedings, 1999
We present several approaches for visible and infrared video image sequence registration, useful for image fusion, target detection and recognition. Feature inconsistency and low contract and noise in the infrared image background consist of the principle difficulty in the image registration for the well separated spectral bands visible and IR images ...
Yunlong Sheng, Xiangjie Yang, Daniel McReynolds, Pierre Valin, Leandre Sevigny   +4 more
openaire   +1 more source

Hilbert transform and mirror-image optical correlators

Applied Optics, 2000
An 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
openaire   +2 more sources

Optical implementation of color image correlation

Optics Communications, 1997
Abstract In contrast to a conventional optical matched filtering system, which converts scalar information of objects into an intensity distribution of coherent light using the so-called incoherent-coherent converter, a new matched filtering system that uses a complex amplitude modulation device and a reference wave is proposed in this paper.
Mitsugu Kakuta, Takashi Obi, Masahiro Yamaguchi, Nagaaki Ohyama   +3 more
openaire   +1 more source

Incoherent Electro-Optic Image Correlator

Optical Engineering, 1984
A real-time optical image correlator is described. An acousto-optic device and an array of light-emitting diodes are the electronic-to-optical transducers for the input and reference images, respectively, in this architecture. The two-dimensional correlation is formed by temporal integration on a two-dimensional CCD detector.
openaire   +1 more source

Optimization Of An Updatable Optical Image Correlator

Optical Engineering, 1987
The 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.
openaire   +1 more source

A Hybrid Optical/Electronic Image Correlator

1987
The 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, R. C. Chittick, I. R. Cooper, P. Waite   +3 more
openaire   +1 more source

Optical correlation of spatial-frequency-shifted images in a photorefractive BSO correlator

Applied Optics, 2004
The optical cross correlation of an image with another image that was spatial-frequency shifted in one dimension was demonstrated in a photorefractive VanderLugt correlator. The first image was stored as a Fourier-transform hologram in a photorefractive Bi12SiO20 crystal (BSO) and was successively correlated with different spatial-frequency-shifted ...
Abtine, Tavassoli, Michael F, Becker
openaire   +2 more sources