Results 171 to 180 of about 9,024 (217)
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Comparative digital holography
Optics Letters, 2002We described a method for direct holographic comparison of the shape or the deformation of two objects when it is not necessary that both samples be located at the same place. In contrast to the well-known incoherent techniques based on inverse fringe projection, this new approach uses a coherent mask that is imaged onto a sample object that has a ...
Wolfgang, Osten +2 more
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Phase-shifting digital holography
Optics Letters, 1997A new method for three-dimensional image formation is proposed in which the distribution of complex amplitude at a plane is measured by phase-shifting interferometry and then Fresnel transformed by a digital computer. The method can reconstruct an arbitrary cross section of a three-dimensional object with higher image quality and a wider viewing angle ...
Ichirou Yamaguchi
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Digital holography with ultimate sensitivity [PDF]
Optics Letters, 2007 3 ...
M Atlan
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2015 IEEE 13th International Conference on Industrial Informatics (INDIN), 2015
Holographic interferometry as a means for nondestructive testing of technical or biological components has got significant momentum by the introduction of digital holography. In this paper after an introduction to holography, holographic interferometry and digital holography practical examples from deformation analysis, form determination, refractive ...
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Holographic interferometry as a means for nondestructive testing of technical or biological components has got significant momentum by the introduction of digital holography. In this paper after an introduction to holography, holographic interferometry and digital holography practical examples from deformation analysis, form determination, refractive ...
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Digital Holography for Security Applications
2012A survey of Digital Holography (DH) and its employment in different application fields is provided. This paper reviews the main principles of the DH focusing on the optical techniques for security purposes. Recording and processing of three dimensional data, secured storage data, the use of Multimedia Sensor Network (MSN) for encrypted data ...
Pellegrini, RM +2 more
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Digital refocusing with incoherent holography
2014 IEEE International Conference on Computational Photography (ICCP), 2014Light field cameras allow us to digitally refocus a photograph after the time of capture. However, recording a light field requires either a significant loss in spatial resolution [11, 21, 10] or a large number of images to be captured [12]. In this paper, we propose incoherent holography for digital refocusing without loss of spatial resolution from ...
Oliver Cossairt +2 more
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Time-averaged digital holography
Optics Letters, 2003We demonstrate that it is possible to study the modal structures of a vibrating object with digitally recorded holograms by use of the time-averaging principle. We investigate the numerical reconstruction from a theoretical point of view, and we show that the numerically reconstructed object from a digital hologram is modulated by the zeroth-order ...
Pascal Picart +2 more
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Digital in-line holography of microspheres
Applied Optics, 2002We have used digital in-line holography (DIH) with numerical reconstruction to image micrometer-sized latex spheres as well as ferrimagnetic beads suspended in gelatin. We have examined in detail theoretically and experimentally the conditions necessary to achieve submicrometer resolution of holographic reconstructions.
W, Xu +3 more
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Aliasing error in digital holography
Applied Optics, 1976The use of the discrete Fourier transform in digital holography introduces aliasing error in the reconstructed image. Spectrum shaping to reduce dynamic range may also result in a serious increase in aliasing error. The effect of aliasing in digital holography is analyzed. It is proposed that the bandwidth be constrained when shaping the image spectrum.
J P, Allebach, N C, Gallagher, B, Liu
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Surface profilometry by digital holography
2017 22nd IEEE International Conference on Emerging Technologies and Factory Automation (ETFA), 2017This 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 +4 more
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