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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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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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Annual Meeting Optical Society of America, 1988
Ordinary holograms are made by interference experiments, digital holograms by computer and plotter. The object does not have to exist physically. Most advantages of digital holograms derive from that fact. Fundamentals and some applications are reviewed: AO display; image processing; and testing.
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Ordinary holograms are made by interference experiments, digital holograms by computer and plotter. The object does not have to exist physically. Most advantages of digital holograms derive from that fact. Fundamentals and some applications are reviewed: AO display; image processing; and testing.
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Coherence requirement in digital holography
Applied Optics, 2012In this paper the coherence requirement for different holographic setups (Fresnel hologram, Fourier hologram, and image-plane hologram) is compared. This analysis is based on the investigation of the recorded interference pattern from the superposition of reference wave and object wave in in-line and off-axis mode. The outcome of this investigation can
Daniel, Claus +2 more
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Numerical optics in digital holography
Adaptive Optics: Analysis and Methods/Computational Optical Sensing and Imaging/Information Photonics/Signal Recovery and Synthesis Topical Meetings on CD-ROM, 2007As digital holography achieves numerical reconstruction of the complex wavefront diffracted by specimen, a numerical optics formalism has been developed: numerical filters replace pinholes in Fourier planes, numerical lenses allow aberrations compensation and image magnification.
Colomb, Tristan +4 more
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Digital diffusers for optical holography
Optics Letters, 1991In optical Fourier holography, diffuse illumination is used to achieve an almost linear recording of the spatial frequencies of the object on film. To this end, usually a ground glass is placed next to the object. However, then a speckle pattern occurs in the reconstruction. In digital holography, diffusers can be designed that do not introduce speckle.
R, Bräuer +3 more
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Digital holography-based steganography
Optics Letters, 2010A steganographic method offering a high hiding capacity is presented in which the techniques of digital holography are used to distribute information from a small secret image across the larger pixel field of a cover image. An iterative algorithm is used to design a phase-only or complex hologram from a padded version of the secret image, quantizing ...
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Optimum quantization in digital holography
Applied Optics, 1978Finite plotter resolution introduces quantization into the representation of digital holograms. By utilizing the statistical properties of the Fourier transform of random phase images, optimum quantization schemes are derived and tabulated for the representation of these transforms.
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