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Coherent Optical Correlation For Defocused Images Recognition
SPIE Proceedings, 1989Deblurring images affected by severe focus defeat gives often poor results. A coherent optical method, the joint Fourier transform correlation, is suggested for the recognition of defocused images. Basing on the symmetry of the crosscorrelation function between an out-of-focus and the in-focus image, the recognition may be attempted simply correlating ...
Paolo Sirotti, Ennio Tofful
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An Optical Image Correlator For Robotic Applications
SPIE Proceedings, 1989The goal of cost effective, high performance optical systems capable of pattern matching tasks has fuelled research for over two decades. It is only recently with the introduction of novel optical/electronic architectures that such systems are becoming viable.
Cawte, Paul P.S. +8 more
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Optical correlation of spatial-frequency-shifted images in a photorefractive BSO correlator
Applied Optics, 2004The 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
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High-resolution optical correlation imaging in a scattering medium
Optics Letters, 2001An optical correlation setup is used to image transparent objects through scattering media, and 10-mum longitudinal and 2.5-mum transverse resolution are achieved. Spectral-bandwidth sampling of the light source is made possible by a tunable dye laser and leads to signal enhancement as a result of sampling interferogram filtering.
Ben Houcine, Karim +4 more
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Optical image-forming system for T-type correlation antennas
Applied Optics, 1978This paper describes an optical processor capable of forming real-time visible images of the radio sky directly from the output signals of a low-frequency T-type antenna array. Current modulator and light-valve technology could accommodate an array with 50-element crossbar and 25-element stem.
G J, Aitken, A M, Kidd
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Multiple Image Recognition By Nonlinear Optical Correlation
SPIE Proceedings, 1989We investigate the performance of a recently introduced bipolar joint transform image correlator when multiple reference objects and single and multiple targets are present at the input plane. The bipolar joint transform correlator uses nonlinearity at the Fourier plane to threshold the Fourier transform interference intensity to only two values, 1 and
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IV Triple-Correlation Imaging in Optical Astronomy
1991Publisher Summary This chapter discusses the triple-correlation imaging in optical astronomy. The chapter discusses the high-resolution imaging methods of speckle masking (bispectrum or triple correlation processing), speckle spectroscopy, and optical long-baseline interferometry with arrays of large telescopes.
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Digital image correlation-assisted phase-sensitive optical coherence tomography
Optics LettersIn this Letter, we introduce a digital image correlation-assisted (DIC-assisted) method to tackle the challenges of phase decorrelation and the inability to measure lateral displacement in phase-sensitive optical coherence tomography (PhS-OCT). This DIC-assisted PhS-OCT (DIC-PhS-OCT) first employs DIC to track displacements from the measured amplitude ...
Bo Dong +4 more
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Correlation-based imaging in adaptive optics
Imaging and Applied Optics 2019 (COSI, IS, MATH, pcAOP), 2019Lehtonen J., Helin Tapio
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Image-based profiling for drug discovery: due for a machine-learning upgrade?
Nature Reviews Drug Discovery, 2020Srinivas Niranj Chandrasekaran +2 more
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