Journal ArticleDOI
Reduction of speckle in digital holography by discrete Fourier filtering.
Jonathan Maycock,Bryan M. Hennelly,John McDonald,Yann Frauel,Albertina Castro,Bahram Javidi,Thomas J. Naughton +6 more
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TLDR
A digital signal processing technique that reduces the speckle content in reconstructed digital holograms based on sequential sampling of the discrete Fourier transform of the reconstructed image field is presented.Abstract:
We present a digital signal processing technique that reduces the speckle content in reconstructed digital holograms. The method is based on sequential sampling of the discrete Fourier transform of the reconstructed image field. Speckle reduction is achieved at the expense of a reduced intensity and resolution, but this trade-off is shown to be greatly superior to that imposed by the traditional mean and median filtering techniques. In particular, we show that the speckle can be reduced by half with no loss of resolution (according to standard definitions of both metrics).read more
Citations
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Journal ArticleDOI
Strategies for reducing speckle noise in digital holography
Vittorio Bianco,Pasquale Memmolo,Marco Leo,Silvio Montresor,Cosimo Distante,Melania Paturzo,Pascal Picart,Bahram Javidi,Pietro Ferraro +8 more
TL;DR: A broad discussion about the noise issue in DH is provided, with the aim of covering the best-performing noise reduction approaches that have been proposed so far and quantitative comparisons among these approaches will be presented.
Journal ArticleDOI
Quasi noise-free digital holography.
Vittorio Bianco,Pasquale Memmolo,Melania Paturzo,Andrea Finizio,Bahram Javidi,Pietro Ferraro +5 more
TL;DR: A novel framework is proposed that combines the concepts of encoding multiple uncorrelated digital holograms, block grouping and collaborative filtering to achieve quasi noise-free DH reconstructions and is comparable to the quality achievable with non-coherent techniques and far beyond the current state of art in DH.
Journal ArticleDOI
Speckle denoising in digital holography by nonlocal means filtering.
TL;DR: The Speckle noise adapted version of the NLM filter is compared with other common speckle denoising filters and is found to give better visual and quantitative results.
Journal ArticleDOI
Resolution limits in practical digital holographic systems
TL;DR: A series of experimental results are presented to confirm the validity of the theoretical model, demonstrating recovery of super- Nyquist frequencies for the first time and how the model can be used to optimize CCD design for lensless DH capture.
Journal ArticleDOI
Imaging live humans through smoke and flames using far-infrared digital holography
Massimiliano Locatelli,E. Pugliese,Melania Paturzo,Vittorio Bianco,Andrea Finizio,Anna Pelagotti,Pasquale Poggi,Lisa Miccio,Riccardo Meucci,Pietro Ferraro +9 more
TL;DR: In this work, easy detection of live, moving people is achieved through both smoke and flames, thus demonstrating the capability of digital holography at 10.6 μm.
References
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Journal ArticleDOI
Phase-shifting digital holography
Ichirou Yamaguchi,Tong Zhang +1 more
TL;DR: A new method 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, which can reconstruct an arbitrary cross section of a three-dimensional object with higher image quality and a wider viewing angle than from conventional digital holography using an off-axis configuration.
Book
Handbook of Holographic Interferometry: Optical and Digital Methods
TL;DR: In this paper, the Fourier Transform is used for the reconstruction of digital Holograms, and the convolutional approach is used to reconstruct the Holographic Histogram.
Journal ArticleDOI
Laser speckle and related phenomena
TL;DR: The second edition of Dainty's widely read book on laser and astronomical speckle as discussed by the authors is a beautiful soft-bound book identical to the first edition (sans typographical errors), except for a rewritten Chapter 7 on "Stellar Speckle Interferometry" and a new Chapter 8 on "Recent Developments" in the overall field of speckles.
Journal ArticleDOI
On a moment theorem for complex Gaussian processes
TL;DR: A general theorem is provided for the moments of a complex Gaussian video process that states that an n th order central product moment is zero if n is odd and is equal to a sum of products of covariances when n is even.