Results 1 to 10 of about 18,946 (293)

Line projection profilometry

Optics Letters
Fringe Projection Profilometry (FPP) is widely used in 3D reconstruction tasks due to its advantages of high accuracy, high data density, and non-contact operation. However, in practical industrial inspections, measurements for high-dynamic range scenarios often suffer from local overexposure or underexposure in captured fringe
Qijian Tang, Yanfei Li, Xiaoli Liu
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Optical heterodyne profilometry

Applied Optics, 1981
A noncontact optical technique for the measurement of surface profile is described, which has a height sensitivity of the order of 1 A. It is based on a common path heterodyne interferometer in which two orthogonally polarized beams of slightly different frequency are focused on the surface to be measured.
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Surface profilometry by digital holography

2017 22nd IEEE International Conference on Emerging Technologies and Factory Automation (ETFA), 2017
This paper presents newly developed method for measurement of surface topography based on frequency scanning digital holography. Digital holography allows for direct computation of the phase field of the wavefront scattered by an object. A tuning of the light source optical frequency results in linear phase variation with respect to the optical ...
Pavel Psota, Vit Ledl, Frantisek Kavan, Pavel Mokry, Ondrej Matousek   +4 more
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Encrypted fringe projection profilometry

Optics Letters
We propose encrypted fringe projection profilometry (E-FPP), a co-keyed phase-code framework that embeds encryption directly into the measurement process of fringe projection profilometry (FPP). Two random phase fields and orthogonal temporal codes jointly encode the projected sequence, binding phase retrieval to legitimate key pairs.
Yang Cheng, Zichen Gui, Le Guan, Ran Jin, Beiwen Li   +4 more
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Aperture-coded confocal profilometry

Optics Letters, 2016
This Letter introduces a novel principle to the confocal profilometry for simultaneous measurement of surface position and tilt. The principle relies on an angle-dependent coding of the illumination of the surface-under-test, achieved by dividing the pupil into several subapertures.
Jaka, Pribošek, Janez, Diaci, Stefan, Sinzinger   +2 more
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Optical Profilometry of Nail Dystrophies

Dermatology, 2009
Optical profilometry after nail shadowing is introduced as a new technique to quantify nail surface alterations. Objective evaluations can be performed in vivo as well as on nail clippings and silicone rubber replicas. Trachyonychia, pittings, grooves and any other type of onychodystrophy are conveniently defined by 3 profilometric parameters: the mean
N, Nikkels-Tassoudji, C, Piérard-Franchimont, P, De Doncker, G E, Piérard   +3 more
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Urethral pressure profilometry in mares

Journal of the American Veterinary Medical Association, 1987
Summary A technique was developed for recording urethral pressure profiles (upp) in mares. Profiles were obtained from 12 clinically normal mares and from 3 mares with urinary incontinence. Variables measured on the profile included intravesicular pressure and maximal urethral closure pressure.
A D, Kay, J P, Lavoie
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Circular fringe projection profilometry

Optics Letters, 2016
In this Letter, a novel three-dimensional (3D) measurement method, called the circular fringe projection profilometry (CFPP), is proposed. Similar to the conventional fringe projection profilometry, CFPP also requires fringe pattern projection and capture, phase demodulation, and phase unwrapping.
Hong, Zhao, Chunwei, Zhang, Changquan, Zhou, Kejian, Jiang, Meiqi, Fang   +4 more
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Optical micro-profilometry for archaeology

SPIE Proceedings, 2005
A quantitative morphological analysis of archaeological objects represents an important element for historical evaluations, artistic studies and conservation projects. At present, a variety of contact instruments for high-resolution surface survey is available on the market, but because of their invasivity they are not well received in the field of ...
Carcagnì P, Daffara C, Fontana R, Gambino MC, Mastroianni M, Mazzotta C, Pampaloni E, Pezzati L   +7 more
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Improved Fourier-transform profilometry

Applied Optics, 2007
An improved optical geometry of the projected-fringe profilometry technique, in which the exit pupil of the projecting lens and the entrance pupil of the imaging lens are neither at the same height above the reference plane nor coplanar, is discussed and used in Fourier-transform profilometry.
Xianfu, Mao, Wenjing, Chen, Xianyu, Su
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