Accedi

Bibliografie tematiche / Digital holography

Indice

Articoli di riviste
Tesi
Libri
Capitoli di libri
Atti di convegni
Rapporti di organizzazioni

Letteratura scientifica selezionata sul tema "Digital holography"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 25 maggio 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Digital holography".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Articoli di riviste sul tema "Digital holography"

1

Kang, Hoonjong, Dimana Nazarova, Branimir Ivanov, Sunghee Hong, Joo Sup Park, Youngmin Kim, Jiyong Park, Nataliya Berberova, Elena Stoykova e Nikola Malinowski. "Digital Holographic Printing Methods for 3D Visualization of Cultural Heritage Artifacts". Digital Presentation and Preservation of Cultural and Scientific Heritage 4 (30 settembre 2014): 69–78. http://dx.doi.org/10.55630/dipp.2014.4.8.

Testo completo

Abstract (sommario):

Holography enables capture and reconstruction of the optical field scattered from three-dimensional (3D) objects. The hologram encodes both amplitude and phase of the field under coherent illumination, whereas photography records only the amplitude by incoherent light. 3D visualization feature of holography motivates expansion of research efforts dedicated to digital holographic imaging methods as a holographic display or a holographic printer. The paper presents two holographic 3D printing techniques which combine digital 3D representation of an object with analog holographic recording. Generation of digital contents is considered for a holographic stereogram printer and a recently proposed wavefront printer. These imaging methods could be applied to specific artifacts which are difficult to be recorded by conventional analog holography.

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Picart, Pascal. "Recent advances in speckle decorrelation modeling and processing in digital holographic interferometry". Photonics Letters of Poland 13, n. 4 (30 dicembre 2021): 73. http://dx.doi.org/10.4302/plp.v13i4.1126.

Testo completo

Abstract (sommario):

Digital holography, and especially digital holographic interferometry, is a powerful approach for the characterization of modifications at the surface or in the volume of objects. Nevertheless, the reconstructed phase data from holographic interferometry is corrupted by the speckle noise. In this paper, we discuss on recent advances in speckle decorrelation noise removal. Two main topics are considered. The first one presents recent results in modelling the decorrelation noise in digital Fresnel holography. Especially the anisotropy of the decorrelation noise is established. The second topic presents a new approach for speckle de-noising using deep convolution neural networks. Full Text: PDF ReferencesP. Picart (ed.), New techniques in digital holography (John Wiley & Sons, 2015). CrossRef T.M. Biewer, J.C. Sawyer, C.D. Smith, C.E. Thomas, "Dual laser holography for in situ measurement of plasma facing component erosion (invited)", Rev. Sci. Instr. 89, 10J123 (2018). CrossRef M. Fratz, T. Beckmann, J. Anders, A. Bertz, M. Bayer, T. Gießler, C. Nemeth, D. Carl, "Inline application of digital holography [Invited]", Appl. Opt. 58(34), G120 (2019). CrossRef M.P. Georges, J.-F. Vandenrijt, C. Thizy, Y. Stockman, P. Queeckers, F. Dubois, D. Doyle, "Digital holographic interferometry with CO2 lasers and diffuse illumination applied to large space reflector metrology [Invited]", Appl. Opt. 52(1), A102 (2013). CrossRef E. Meteyer, F. Foucart, M. Secail-Geraud, P. Picart, C. Pezerat, "Full-field force identification with high-speed digital holography", Mech. Syst. Signal Process. 164 (2022). CrossRef L. Lagny, M. Secail-Geraud, J. Le Meur, S. Montresor, K. Heggarty, C. Pezerat, P. Picart, "Visualization of travelling waves propagating in a plate equipped with 2D ABH using wide-field holographic vibrometry", J. Sound Vib. 461 114925 (2019). CrossRef L. Valzania, Y. Zhao, L. Rong, D. Wang, M. Georges, E. Hack, P. Zolliker, "THz coherent lensless imaging", Appl. Opt. 58, G256 (2019). CrossRef V. Bianco, P. Memmolo, M. Leo, S. Montresor, C. Distante, M. Paturzo, P. Picart, B. Javidi, P. Ferraro, "Strategies for reducing speckle noise in digital holography", Light: Sci. Appl. 7(1), 1 (2018). CrossRef V. Bianco, P. Memmolo, M. Paturzo, A. Finizio, B. Javidi, P. Ferraro, "Quasi noise-free digital holography", Light. Sci. Appl. 5(9), e16142 (2016). CrossRef R. Horisaki, R. Takagi, J. Tanida, "Deep-learning-generated holography", Appl. Opt. 57(14), 3859 (2018). CrossRef E. Meteyer, F. Foucart, C. Pezerat, P. Picart, "Modeling of speckle decorrelation in digital Fresnel holographic interferometry", Opt. Expr. 29(22), 36180 (2021). CrossRef M. Piniard, B. Sorrente, G. Hug, P. Picart, "Theoretical analysis of surface-shape-induced decorrelation noise in multi-wavelength digital holography", Opt. Expr. 29(10), 14720 (2021). CrossRef P. Picart, S. Montresor, O. Sakharuk, L. Muravsky, "Refocus criterion based on maximization of the coherence factor in digital three-wavelength holographic interferometry", Opt. Lett. 42(2), 275 (2017). CrossRef P. Picart, J. Leval, "General theoretical formulation of image formation in digital Fresnel holography", J. Opt. Soc. Am. A 25, 1744 (2008). CrossRef S. Montresor, P. Picart, "Quantitative appraisal for noise reduction in digital holographic phase imaging", Opt. Expr. 24(13), 14322 (2016). CrossRef S. Montresor, M. Tahon, A. Laurent, P. Picart, "Computational de-noising based on deep learning for phase data in digital holographic interferometry", APL Photonics 5(3), 030802 (2020). CrossRef M. Tahon, S. Montresor, P. Picart, "Towards Reduced CNNs for De-Noising Phase Images Corrupted with Speckle Noise", Photonics 8(7), 255 (2021). CrossRef E. Meteyer, S. Montresor, F. Foucart, J. Le Meur, K. Heggarty, C. Pezerat, P. Picart, "Lock-in vibration retrieval based on high-speed full-field coherent imaging", Sci. Rep. 11(1), 1 (2021). CrossRef

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Balasubramani, Vinoth, Małgorzata Kujawińska, Cédric Allier, Vijayakumar Anand, Chau-Jern Cheng, Christian Depeursinge, Nathaniel Hai et al. "Roadmap on Digital Holography-Based Quantitative Phase Imaging". Journal of Imaging 7, n. 12 (26 novembre 2021): 252. http://dx.doi.org/10.3390/jimaging7120252.

Testo completo

Abstract (sommario):

Quantitative Phase Imaging (QPI) provides unique means for the imaging of biological or technical microstructures, merging beneficial features identified with microscopy, interferometry, holography, and numerical computations. This roadmap article reviews several digital holography-based QPI approaches developed by prominent research groups. It also briefly discusses the present and future perspectives of 2D and 3D QPI research based on digital holographic microscopy, holographic tomography, and their applications.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Zhang, Yu Fei, e Yi Quan Wu. "A Method for Eliminating Zero-Order Image in Digital Holograph Based on Contourlet Transform". Advanced Materials Research 760-762 (settembre 2013): 80–83. http://dx.doi.org/10.4028/www.scientific.net/amr.760-762.80.

Testo completo

Abstract (sommario):

In the reconstruction process of digital holograph, zero-order image has a bad impact on the quality of real image. In this paper, a new way to eliminate zero-order image in digital holography is proposed. Firstly, digital holography image is decomposed by contourlet transform, then remove the low frequency. The new digital holography image is obtained by inverse contourlet transform. Experiments show that, compared with spatial filtering, frequency domain filtering, laplacian filtering and eliminate zero-order image method based on wavelet, the new method proposed in this paper can eliminate zero-order image better, whats more, the real image is also strengthened in some way.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Iano, Randrianasoa, e Randriamaroson Mahandrisoa. "Enhancing Real-Time Pyramid Holographic Display Through Iterative Algorithm Optimization for 3D Image Reconstruction". American Journal of Optics and Photonics 12, n. 1 (29 aprile 2024): 9–17. http://dx.doi.org/10.11648/j.ajop.20241201.12.

Testo completo

Abstract (sommario):

Holography, a crucial technology for 3D visualization, strives to create realistic relief images. This research aims to enhance hologram quality and viewer experience by optimizing the image-processing pipeline. Conventional holographic displays face challenges due to their bulkiness and limited viewing angles. To overcome these limitations, this study proposes a novel approach that integrates digital holography with holographic pyramid technology. Digital holography uses computer algorithms for hologram generation, while holographic pyramid technology projects images onto a reflective pyramid for 3D display. The drawback of holographic pyramid displays in low-light environments is addressed through increased diffraction to enhance image resolution. This integrated approach involves comprehensive research, including an examination of existing methods. The anticipated outcome is holograms with improved visibility and resolution from multiple angles. The research presents an initial image preprocessing phase, succeeded by sophisticated processing employing iterative algorithms. This aims to diminish the image size while upholding its quality, thereby achieving an image suitable for pyramidal display. The fusion of digital holography and holographic pyramid display shows promise for immersive visual experiences. However, advancements in processing techniques may lead to increased material complexity, posing a challenge. Through this research, the system aims to unlock creative potentials and pave the way for enhanced holographic displays in various applications.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Chen, Duofang, Lin Wang, Xixin Luo, Hui Xie e Xueli Chen. "Resolution and Contrast Enhancement for Lensless Digital Holographic Microscopy and Its Application in Biomedicine". Photonics 9, n. 5 (19 maggio 2022): 358. http://dx.doi.org/10.3390/photonics9050358.

Testo completo

Abstract (sommario):

An important imaging technique in biomedicine, the conventional optical microscopy relies on relatively complicated and bulky lens and alignment mechanics. Based on the Gabor holography, the lensless digital holographic microscopy has the advantages of light weight and low cost. It has developed rapidly and received attention in many fields. However, the finite pixel size at the sensor plane limits the spatial resolution. In this study, we first review the principle of lensless digital holography, then go over some methods to improve image contrast and discuss the methods to enhance the image resolution of the lensless holographic image. Moreover, the applications of lensless digital holographic microscopy in biomedicine are reviewed. Finally, we look forward to the future development and prospect of lensless digital holographic technology.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Wang, Yu Tian, Dong Sheng Wang e Wei Wei Pan. "The Analysis and Research on Digital Holography Signal Based on Wavelet Theory". Advanced Materials Research 216 (marzo 2011): 414–18. http://dx.doi.org/10.4028/www.scientific.net/amr.216.414.

Testo completo

Abstract (sommario):

When introduce the wavelet theory to filter the hologram and the reconstructed image in the digital holography, the noise of the reconstructed image is greatly reduced. In the off-axis digital holography, the zero-order wave is decreased dramatically when after a wavelet filter, at the same time, the speckle noise is also reduced, and it turns out that the resolution of the reconstruction image is improved greatly. The system launches the research thoroughly on the three-dimensional body digital holographic technology, from the theory to the application, from the simulation to the experiment, and has elaborated and analyzed each characteristic of three-dimensional body digital holographic technology. It proposes many kinds of improved effective method of three-dimensional body digital holographic restructuring information, and finally has effectively explored the three-dimensional body digital holographic technology application through the experiment.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Takahashi, Yoshitaka, Masatoshi Saito, Toru Nakajima e Masakazu Shingu. "Determination of Phase Shift by Digital Holography". Applied Mechanics and Materials 888 (febbraio 2019): 43–46. http://dx.doi.org/10.4028/www.scientific.net/amm.888.43.

Testo completo

Abstract (sommario):

In phase shifting interferometry phase shift is applied by various ways, but applying it with high accuracy, especially by LD current modulation, is not easy. In order to determine the accurate phase shift a new method has been proposed that the value of LD current corresponding to π/2 phase shift can be determined by phase shifting digital holography. The measured data of standard in surface shape measurement were used for calibration, and the obtained value was confirmed to cause noise reduction and improvement of holographic reconstructed images in digital holography.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Zhang, Tong, Ichirou Yamaguchi e Hywel Morgan. "Digital Holographic Microscopy". Microscopy and Microanalysis 5, S2 (agosto 1999): 362–63. http://dx.doi.org/10.1017/s1431927600015130.

Testo completo

Abstract (sommario):

We applied phase-shifting digital holography to microscopy in this paper. At first lensless microscopy is proposed, in which no optical adjustment is necessary. Then, the method is applied to relax the limitation of focal depth in traditional optical microscopy. A theory for image formation and experimental verification using a few specimens are described.keywords: microscopy, digital holography, phase shiftingDue to the finite focal depth of an imaging lens, a limitation to normal optical microscopy-is that, only the 2-dimensional (2-D) information of an object can be obtained at one time. Besides, it is not convenient for quantitative analysis the observed image. Optical sectioning microscopy (OSM) and scanning confocal microscopy (SCM) which use opto-electronic detection have been proposed for quantitative analysis of a 3-D object. However, the former requires critical mechanical adjustment, while the latter uses timeconsuming mechanical 3-D scanning. Holographic microscopy can solve these problems because it can record 3-D information at one time. But, the chemical processing of holograms and the mechanical focusing at the reconstructed images cause more or less trouble. A 3-D imaging technique without use of photographic recording called optical scanning holography has recently been reported. However, there are also some trouble owing to the twin-image noise.

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Zhao, Jieming, Zhan Gao, Shengjia Wang, Yuhao Niu, Lin Deng e Ye Sa. "Multi-Object Deep-Field Digital Holographic Imaging Based on Inverse Cross-Correlation". Applied Sciences 13, n. 20 (18 ottobre 2023): 11430. http://dx.doi.org/10.3390/app132011430.

Testo completo

Abstract (sommario):

To address the complexity of small or unique reconstruction distances in digital holography, we propose an inverse cross-correlation-based algorithm for the digital holographic imaging of multiplanar objects with a large depth of field. In this method, a planar output mapping is closely around the objects, and it is established by calculating the image inverse cross-correlation matrix of the reconstructed image at similar reconstruction distances, whereby the object edges serve as the result guide. Combining the search for edge planes with the depth estimation operator, the depth of field of digital holography is improved, thus allowing for a digital holography that is capable of meeting the requirements of the holographic imaging of multiplanar objects. Compared with the traditional depth estimation operator method, the proposed method solves the reconstruction ambiguity problem in multiple planes with a simple optical path, and no additional optical or mechanical devices need to be added, thus greatly improving the reconstruction quality. The numerical calculation results and the experimental results with multiplanar samples validate the effectiveness of the proposed method.

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Tesi sul tema "Digital holography"

1

Williams, Logan Andrew. "Digital Holography for Three Dimensional Tomographic and Topographic Measurements". University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1398436841.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Hjartarson, Örn. "Separation of lobes in Multispectral Digital Holography". Thesis, Umeå universitet, Institutionen för fysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-64314.

Testo completo

Abstract (sommario):

Through a holographic recording a property from the third dimension, the depth, is obtained in the form of a phase map of the incident light. One wavelength holography will have a unique phase for the depth range corresponding to the wavelength of the light and outside this range the real depth can not be resolved. By introducing more wavelengths to the measurement the unique phase combination of the waves will have a wider range and larger objects can be resolved. Up to six wavelengths can be simultaneous recorded by making them occupy different spatial frequencies. A set of spatial frequencies together describing a property of the wave is referred to as a lobe. For more than 6 wavelengths and a larger depth range produced by a more seldom repeated unique phase combination the individual waves will occupy the same frequencies, i.e. the lobes overlap. The separation of overlapping lobes is essential in order to make precise and time independent measurements of large and/or moving objects. To separate the lobes the complex fields, i.e. the phases together with the amplitudes, were simulated to propagate a distance and again recorded. The propagation leads to a phase shift of the spatial frequencies which reveals the complex fields in the case of two overlapping wavelengths. For three overlapping wavelengths the resolution, i.e spatial frequencies describing the object, has to be reduced in order to determine the individual complex fields. Since the propagation is a linear transformation for the frequencies that do not overlap, only the overlapping elements whose propagation is nonlinear produce new information. The new information gained is therefore independent of the number of wavelengths used which limits the exact determination of the fields to two wavelengths. Through the holographic recording another property of the complex field is obtained which is the superimposed individual intensities. This bounds the complex fields to certain values, i.e. restricts the possible amplitude of the waves. The recording in the two planes produces two intensity distributions which both must be satisfied by the complex fields. The optimization model for this was formulated and a simple optimization algorithm was implemented. Instead of an equality constraint of the intensities the inequality constraint was implemented, mainly due to that the optimization process was out of the scope of the thesis and the inequality constraint resulted in a simple implementation. The result pointed out important properties even though the optimization could not separate the fields satisfactorily for more than three wavelengths. The inequality constraint contains enough information to solve the case of three overlapping wavelengths.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Tapsell, John Peter. "Direct-Write Digital Holography". Thesis, University of Sussex, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487902.

Testo completo

Abstract (sommario):

Chapter 1 gives a brief history of the field of holography along with an overview of this thesis. A more detailed description of holography is provided in Chapter 2 along with a discussion of digital holography. Chapter 3 examines the design of a one-step monochromatic hologram printer capable producing white-light viewable transmission holograms created with the aid of an LCOS display system and printed in a dot-matrix sequence. The lens system employed includes a microlens array and an afocal relay telescope which are both quantitatively examined in order to maximise the contrast, diffraction efficiency and depth of view of the final hologram image. A brief overview of speckle reduction techniques and their applicability to pulsed digital holography is presented along with experimental results of the use of a microlens array to reduce speckle effects. Chapter 4 presents an analysis of the unwanted side effects of the angular intensity distribution of a hologram pixel, using a case study for analysis. Chapter 5 examines methods for increasing both the printing speed and resolution of the hologram printer. Chapter 6 describes the analysis and design of a temperature-energy feedback system to correct for pulsed laser instabilities arising from mode beating due to temperature variations. Chapter 7 provides a conclusion to the work and discusses possible future developments.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Lopez, Marcio André Prieto Aparicio. "Microscopia holográfica digital aplicada na análise de tecidos biológicos". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-23032013-124944/.

Testo completo

Abstract (sommario):

Este trabalho teve como objetivo a aplicação do Microscópio Holográfico Digital para análise de amostras biológicas, por meio de imagens de parâmetros físicos e informação quantitativa de uma amostra, gerados através de hologramas digitais, o que não ocorre na holografia clássica. O processamento e análise dos hologramas digitais foi efetuada por um programa escrito por meio do software MatLab, empregando o método de Dupla Propagação. São explicados outros métodos para tratamento de hologramas digitais, presentes no programa. O método de Dupla Propagação foi discutido, destacando suas vantagens frente aos outros métodos. Foi aplicado o método de Volkov para a retirada de ambiguidade de fase. O processo de montagem do Microscópio Holográfico Digital foi descrito, por apresentar modificações em relação ao protótipo inicial adotado. Sete amostras foram analisadas no Microscópio Holográfico Digital, três de calibração e quatro para análise - sangue e solução concentrada de proteína denominada Beta2 Glicoproteína tipo I, ou Beta2-GPI. Para calibração, foram realizados testes de formação de imagem, realizando comparação em quatro microscópios descritos e explicados em funcionamento e princípio envolvidos na formação de imagens, utilizando a mesma amostra; e verificação das dimensões de uma amostra, por meio de medição usando ferramentas disponíveis no programa. Uma amostra de sangue de um indivíduo heterozigoto para Hemoglobina S (anemia falciforme) e uma amostra de sangue de um indivíduo homozigoto para hemoglobina A1 (controle normal) foram empregadas na forma de filmes líquidos secos sobre lâminas de vidro (extensão sanguínea). O uso de fixação foi avaliado com a amostra controle. Foram geradas imagens em duas e três dimensões para as amostras biológicas, reproduzindo as estruturas morfológicas de cada. Para a proteína Beta2-GPI, a análise envolveu somente imagens, sem extração de valores; apesar disso, os resultados mostraram possibilidades de aplicações em estudos futuros. Grandezas físicas foram calculadas para dois dos componentes sanguíneos (Plasma e Eritrócito), mostrando valores próximos daqueles conhecidos anteriormente. Entretanto, alguns valores foram considerados estimativas novas, por não se conhecer, até o momento, nenhum cálculo efetuado anteriormente. A análise comprovou a formação de imagens e a capacidade de mensuração oferecida pelo aparelho. Devido ao parâmetro da fase, foi possível extrair informações em três dimensões.
This work aimed the implementation of the Digital Holographic Microscope for the analysis of biological samples, using physical parameters images and quantitative data from a sample, both generated through digital holograms, which does not occur in Classical holography. Processing and analysis of holograms were performed by a program written using the MatLab software, applying the Double Propagation method. Other methods for the treatment of digital holograms were explained. The Double Propagation method was discussed, highlighting their advantages over other methods. The method of Volkov was applied for removing phase ambiguity. The Digital Holographic Microscope assembly process was described, because of the modifications made to the initial prototype adopted. Seven samples were analyzed in the digital holographic microscope, three of them for calibration and the other to the analysis - blood and a concentrated solution of a protein called type I Beta2 Glycoprotein, or Beta2-GPI. Calibration tests were made by observing and comparing four image microscopes, described and explained in operation and principles involved in the formation of images, using the same testing sample; and checking the dimensions of another sample through measurement, using digital tools available in the program. Hb S heterozygous (Sickle Cell disease) and Hb A1 homozygous (Control) blood samples were prepared in microscope slide glasses. Images were acquired in two and three dimensions for biological samples, reproducing their morphological structures. For Beta2-GPI, the analysis involved only images, and no values were extracted; nevertheless, the results showed potential applications in future studies. Physical quantities were calculated for two blood components (Plasma and Erythrocyte), showing values closer to those previously known. However, some values were considered new estimates, because there is no knowledge of any calculation made previously, until now, using Digital Holographic Microscopy. The analysis proved the formation of images and the measurement capacity offered by the apparatus. Due to the phase parameter, we were able to extract information in three dimensions.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Li, Yan. "Digital holography and optical contouring". Thesis, Liverpool John Moores University, 2009. http://researchonline.ljmu.ac.uk/4539/.

Testo completo

Abstract (sommario):

Digital holography is a technique for the recording of holograms via CCD/CMOS devices and enables their subsequent numerical reconstruction within computers, thus avoiding the photographic processes that are used in optical holography. This thesis investigates the various techniques which have been developed for digital holography. It develops and successfully demonstrates a number of refinements and additions in order to enhance the performance of the method and extend its applicability. The thesis contributes to both the experimental and numerical analysis aspects of digital holography. Regarding experimental work: the thesis includes a comprehensive review and critique of the experimental arrangements used by other workers and actually implements and investigates a number of these in order to compare performance. Enhancements to these existing methods are proposed, and new methods developed, aimed at addressing some of the perceived short-comings of the method. Regarding the experimental aspects, the thesis specifically develops:• Super-resolution methods, introduced in order to restore the spatial frequencies that are lost or degraded during the hologram recording process, a problem which is caused by the limited resolution of CCD/CMOS devices.• Arrangements for combating problems in digital holography such as: dominance of the zero order term, the twin image problem and excessive speckle noise.• Fibre-based systems linked to tunable lasers, including a comprehensive analysis of the effects of: signal attenuation, noise and laser instability within such systems.• Two-source arrangements for contouring, including investigating the limitations on achievable accuracy with such systems. Regarding the numerical processing, the thesis focuses on three main areas. Firstly, the numerical calculation of the Fresnel-Kirchhoff integral, which is of vital importance in performing the numerical reconstruction of digital holograms. The Fresnel approximation and the convolution approach are the two most common methods used to perform numerical reconstruction. The results produced by these two methods for both simulated holograms and real holograms, created using our experimental systems, are presented and discussed. Secondly, the problems of the zero order term, twin image and speckle noise are tackled from a numerical processing point of view, complementing the experimental attack on these problems. A digital filtering method is proposed for use with reflective macroscopic objects, in order to suppress both the zero-order term and the twin image. Thirdly, for the two-source contouring technique, the following issues have been discussed and thoroughly analysed: the effects of the linear factor, the use of noise reduction filters, different phase unwrapping algorithms, the application of the super-resolution method, and errors in the illumination angle. Practical 3D measurement of a real object, of known geometry, is used as a benchmark for the accuracy improvements achievable via the use of these digital signal processing techniques within the numerical reconstruction stage. The thesis closes by seeking to draw practical conclusions from both the experimental and numerical aspects of the investigation, which it is hoped will be of value to those aiming to use digital holography as a metrology tool.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Mann, Christopher J. "Quantiative biological micrsocopy by digital holography". [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001709.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Mann, Christopher J. "Quantiative biological microsocopy by digital holography". Scholar Commons, 2006. http://scholarcommons.usf.edu/etd/2614.

Testo completo

Abstract (sommario):

In this dissertation, improved techniques in digital holography, that have produced high-resolution, high-fidelity images, are discussed. In particular, the angular spectrum method of calculating holographic optical field is noted to have several advantages over the more commonly used Fresnel transformation or Huygens convolution method. It is observed that spurious noise and interference components can be tightly controlled through the analysis and filtering of the angular spectrum. In the angular spectrum method, the reconstruction distance does not have a lower limit, and the off-axis angle between the object and reference waves can be lower than that of the Fresnel requirement, while still allowing the zero-order background to be cleanly separated. Holographic phase images are largely immune from the coherent noise commonly found in amplitude images. With the use of a miniature pulsed laser, the resulting images have 0.5um diffraction-limited lateral resolution and the phase profile is accurate to about several nanometers of optical path length. Samples such as ovarian cancer cells (SKOV-3) and mouse-embryo fibroblast cells have been imaged. These images display intra-cellular and intra-nuclear organelles with clarity and quantitative accuracy. This technique clearly exceeds currently available methods in phase-contrast opticalmicroscopy in both resolution and detail and provides a new modality for imaging morphology of cellular and intracellular structures that is not currently available. Furthermore, we also demonstrate that phase imaging digital holographic movies provide a novel method of non-invasive quantitative viewing of living cells and other objects. This technique is shown to have significant advantages over conventional microscopy.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Dong, Hongpai. "Applications and developments of digital holography". Thesis, University of Aberdeen, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430382.

Testo completo

Abstract (sommario):

Digital holography is a new technology emerged in 1994. Because of developments of Laser, personal computer, and CCD sensor, digital holography is finding a remarkably wide range for applications. The reconstruction algorithm is the corner stone of digital holography. It simulates and models the optical reconstruction process with numerical algorithms. A number of reconstruction algorithms have been developed for digital holography in recent years, for instance, the digital implementations of the Fresnel transform, the Fraunhofer transform, and Wavelet transform. We examined all above reconstruction algorithms and developed our own variants of Angular Spectrum and Wavelet/Chirplet reconstruction algorithms. Further to these reconstruction algorithms, we developed miscellaneous algorithms to make digital holography more sophisticated. To detect the focus of an individual hologram, auto-focusing algorithms are developed. To break the resolution limitation introduced by the CCD sensor we present digital in-line holography illuminated by divergent light and corresponding reconstruction algorithms. To expand digital holography in a wider range of common applications, digital video holography is exploited. The holographic video can be reconstructed in both z and time axes. We integrated all the algorithms into software for holographic recording and processing electronically. We also applied the digital holography in a real biological application, sediment erosion study.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Khodadad, Davood. "Multiplexed Digital Holography incorporating Speckle Correlation". Doctoral thesis, Luleå University of Technology, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-55810.

Testo completo

Abstract (sommario):

In manufacturing industry there is a high demand for on line quality control to minimize therisk of incorrectly produced objects. Conventional contact measurement methods are usuallyslow and invasive, meaning that they cannot be used for soft materials and for complexshapes without influencing the controlled parts. In contrast, interferometry and digitalholography in combination with computers become faster, more reliable and highly accurateas an alternative non-contact technique for industrial shape evaluation. For example in digitalholography, access to the complex wave field and the possibility to numerically reconstructholograms in different planes introduce a new degree of flexibility to optical metrology. Withdigital holography high resolution and precise three dimensional (3D) images of themanufactured parts can be generated. This technique can also be used to capture data in asingle exposure, which is important when doing measurements in a disturbed environment. The aim of this thesis is devoted to the theoretical and experimental development of shapeand deformation measurements. To perform online process control of free-formmanufactured objects, the measured shape is compared with the CAD-model to obtaindeviations. To do this, a new technique to measure surface gradients and shape based onsingle-shot multiplexed dual-wavelength digital holography and image correlation of speckledisplacements is demonstrated. Based on an analytical relation between phase gradients andspeckle displacements it is shown that an object is retrieved uniquely to shape, position anddeformation without the unwrapping problems that usually appear in dual-wavelengthholography. The method is first demonstrated using continues-wave laser light from twotemperature controlled laser diodes operating at 640 nm. Then a specially designed dual corediode pumped fiber laser that produces pulsed light with wavelengths close to 1030 nm isused. In addition, a Nd:YAG laser with the wavelength of 532 nm is used for 3D deformationmeasurements. One significant problem when using the dual-wavelength single-shot approach is that phaseambiguities are built in to the system that needs to be corrected. An automatic calibrationscheme is therefore required. The intrinsic flexibility of digital holography gives a possibilityto compensate these aberrations and to remove errors, fully numerically without mechanicalmovements. In this thesis I present a calibration method which allows multiplexed singleshotonline shape evaluation in a disturbed environment. It is shown that phase maps andspeckle displacements can be recovered free of chromatic aberrations. This is the first time that a multiplexed single-shot dual-wavelength calibration is reported by defining a criteria tomake an automatic procedure. Further, Digital Speckle Photography (DSP) is used for the full field measurement of 3Ddeformations. In order to do 3D deformation measurement, usually multi-cameras andintricate set-up are required. In this thesis I demonstrate the use of only one single camera torecord four sets of speckle patterns recorded by illuminating the object from four differentdirections. In this manner, meanwhile 3D speckle displacement is calculated and used for themeasurement of the 3D deformations, wrapping problems are also avoided. Further, the samescale of speckle images of the surface for all four images is guaranteed. Furthermore, a needfor calibration of the 3D deformation measurement that occurs in the multi-camera methods,is removed. By the results of the presented work, it is experimentally verified that the multiplexed singleshotdual wavelength digital holography and numerically generated speckle images can beused together with digital speckle correlation to retrieve and evaluate the object shape. Usingmultidirectional illumination, the 3D deformation measurements can also be obtained. Theproposed method is robust to large phase gradients and large movements within the intensitypatterns. The advantage of the approach is that, using speckle displacements, shape anddeformation measurements can be performed even though the synthetic wavelength is out ofthe dynamic range of the object deformation and/or height variation.

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Suck, Sarah Yasmine. "Digital heterodyne holography for plasmonic nanostructures". Paris 6, 2011. http://www.theses.fr/2011PA066681.

Testo completo

Abstract (sommario):

Dans cette thèse, nous étudions les caractéristiques de diffusion de nanostructures plasmoniques tout en adaptant et améliorant l'holographie hétérodyne numérique, qui est une technique d'imagerie plein champ pour mesurer en trois dimensions le diagramme de rayonnement. En outre, nous avons effectué de nombreuses mesures spectroscopiques pour enregistrer les spectres de diffusion de nanoobjets uniques. Afin d'obtenir une compréhension plus profonde des caractéristiques du champ diffusé que nous mesurons, nous avons développé un modèle numérique basé sur la méthode des éléments finis. Ce modèle nous a permis de simuler le champ proche et le champ lointain d'une nanostructure avec une onde incidente en réflexion ou en transmission. Nous obtenons un excellent accord entre nos résultats expérimentaux et calculés. Dans cette thèse, nous avons étudié de nombreux nanostructures d'or fabriquées sur du verre par lithographie électronique. Des structures simples nous ont permis de valider la technique. Des objets plus sophistiques nous ont ensuite permis de constater que leur diagramme de diffusion est extrêmement sensible aux facteurs externes et internes, tels que la polarisation et la longueur d'onde de la lumière incidente ou la géométrie de la structure et sa longueur d'onde de résonance. En outre, nous montrons que la technique de l'holographie hétérodyne photothermique mesure directement l'augmentation de la température, et ainsi, se présente comme une nouvelle méthode pour étudier la distribution de la chaleur dans des nanostructures plasmoniques.

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Libri sul tema "Digital holography"

1

Li, Jun-chang, e Pascal Picart, a cura di. Digital Holography. Hoboken, NJ USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118562567.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

1945-, Li Junchang, a cura di. Digital holography. London: ISTE, 2012.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Yaroslavsky, Leonid. Digital Holography and Digital Image Processing. Boston, MA: Springer US, 2004. http://dx.doi.org/10.1007/978-1-4757-4988-5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Picart, Pascal, a cura di. New Techniques in Digital Holography. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781119091745.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Schnars, Ulf, Claas Falldorf, John Watson e Werner Jüptner. Digital Holography and Wavefront Sensing. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44693-5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Werner, Jueptner, a cura di. Digital holography: Digital hologram recording, numerical reconstruction, and related techniques. Berlin: Springer, 2005.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Steinchen, Wolfgang. Digital shearography: Theory and application of digital Speckle pattern shearing interferometry. Bellingham, Wash: SPIE Press, 2003.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Poon, Ting-Chung, a cura di. Digital Holography and Three-Dimensional Display. Boston, MA: Springer US, 2006. http://dx.doi.org/10.1007/0-387-31397-4.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

9

author, Aylo Rola 1981, e Williams, Logan A., 1977- author, a cura di. Analog and digital holography with MATLAB. Bellingham, Washington: SPIE Press, 2015.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Digital holography and digital image processing: Principles, methods, algorithms. Boston: Kluwer Academic, 2004.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Capitoli di libri sul tema "Digital holography"

1

Kostuk, Raymond K. "Digital Holography". In Holography, 153–73. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2019] |: CRC Press, 2019. http://dx.doi.org/10.1201/9780429185830-7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Narayanamurthy, C. S. "Digital holography". In Contemporary Holography, 53–86. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9780367470975-5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Toal, Vincent. "Digital Holography". In Introduction to Holography, 281–308. 2^a ed. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003155416-17.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Shimobaba, Tomoyoshi, e Tomoyoshi Ito. "Digital holography". In Computer Holography, 91–118. Boca Raton, FL : CRC Press/Taylor & Francis Group, 2018.: CRC Press, 2019. http://dx.doi.org/10.1201/9780429428005-4.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Schnars, Ulf, Claas Falldorf, John Watson e Werner Jüptner. "Digital Holography". In Digital Holography and Wavefront Sensing, 39–68. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44693-5_3.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Khare, Kedar. "Digital Holography". In Fourier Optics and Computational Imaging, 215–33. Chichester, UK: John Wiley & Sons, Ltd, 2015. http://dx.doi.org/10.1002/9781118900352.ch16.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Khare, Kedar, Mansi Butola e Sunaina Rajora. "Digital Holography". In Fourier Optics and Computational Imaging, 189–216. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-18353-9_14.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Li, Jun-chang, e Pascal Picart. "Mathematical Prerequisites". In Digital Holography, 1–26. Hoboken, NJ USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118562567.ch1.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Li, Jun-chang, e Pascal Picart. "The Scalar Theory of Diffraction". In Digital Holography, 27–76. Hoboken, NJ USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118562567.ch2.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Li, Jun-chang, e Pascal Picart. "Calculating Diffraction by Fast Fourier Transform". In Digital Holography, 77–114. Hoboken, NJ USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118562567.ch3.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Atti di convegni sul tema "Digital holography"

1

Johnson, K. M., B. Cormack, A. Strasser, K. Dixon e J. Carsten. "The Digital Holographic Sundial". In Holography. Washington, D.C.: Optica Publishing Group, 1986. http://dx.doi.org/10.1364/holography.1986.wb2.

Testo completo

Abstract (sommario):

The oldest optical instrument is the gnomen1; a shadow casting rod used by the ancient Greeks to keep time. Depending on the position of the sun in the sky, the shadow has a unique length which is marked out on a horizontal surface. A sundial consists of a gnomen and graduated markings on a horizontal plane.

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Brown, Kevin G. "Digital holography". In LkForest 91, a cura di Tung H. Jeong. SPIE, 1992. http://dx.doi.org/10.1117/12.57777.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Lohmann, Adolf W. "Digital holography". In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1988. http://dx.doi.org/10.1364/oam.1988.wu1.

Testo completo

Abstract (sommario):

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.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Yaroslaysky, L. P. "Digital Optics:Tasks,Algorithms,Computers". In Holography '89, a cura di Yuri N. Denisyuk e Tung H. Jeong. SPIE, 1990. http://dx.doi.org/10.1117/12.963868.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Otani, Mayu, e Kunihiro Sato. "Holographic microscope by one-shot digital holography". In Digital Holography and Three-Dimensional Imaging. Washington, D.C.: OSA, 2011. http://dx.doi.org/10.1364/dh.2011.dtuc23.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Wan, Weiping, Sheng Ye, Yue Han, Qihuang Gong e Yan Li. "Vectorial metasurface holography for encryption and dynamic display". In Digital Holography and Three-Dimensional Imaging. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/dh.2022.w5a.15.

Testo completo

Abstract (sommario):

Through controlling the phase difference of two different polarization-dependent holographic images, an extra vectorial holography with flexible spatial polarization distribution is encrypted with high resolution and dynamically reconstructed in far field.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Goodman, Matthew A., R. Krishna Mohan e Wm Randall Babbitt. "Range Selective Digital Holographic Imaging Using FMCW Lidar". In Digital Holography and Three-Dimensional Imaging. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/dh.2022.w7a.2.

Testo completo

Abstract (sommario):

Integrating frequency modulated continuous wave lidar techniques into digital holographic imaging allows for high resolution range selective holography. This technique is presented, showing cancellation of obscurations as well as enhanced contrast in images of objects.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Javidi, Bahram. "Advances in Automated Disease Identification with Digital Holography [Plenary Address]". In Digital Holography and Three-Dimensional Imaging. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/dh.2022.tu3a.1.

Testo completo

Abstract (sommario):

This Plenary is an overview of advances in automated disease identification with low-cost field portable digital holographic systems integrated with dedicated algorithms. Recent applications of digital holography and dedicated algorithms for rapid COVID-19 detection will be presented.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Zhang, Yunping, e Edmund Y. Lam. "Enabling Low-light Digital Holography with a Quanta Image Sensor". In Digital Holography and Three-Dimensional Imaging. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/dh.2022.th4a.6.

Testo completo

Abstract (sommario):

We demonstrate a digital holographic imaging system where the hologram is captured by a quanta image sensor (QIS), and the object wavefront is then computationally retrieved. This scheme enables digital holography at a very low signal level via individual photon detection.

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Dyomin, V. V., A. Y. Davydova e I. G. Polovtsev. "Underwater digital holography of plankton with advanced monitoring capabilities for bioindication in situ". In Digital Holography and Three-Dimensional Imaging. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/dh.2023.hm2d.3.

Testo completo

Abstract (sommario):

The study presents a bioindication technology based on the underwater digital holography with advanced capabilities for plankton and its behavioral characteristics monitoring in situ. The long-term digital holographic experiment on biotesting was performed in the water area in the Arctic.

Gli stili APA, Harvard, Vancouver, ISO e altri

Rapporti di organizzazioni sul tema "Digital holography"

1

Powell, Rodney M. Digital Holography. Fort Belvoir, VA: Defense Technical Information Center, febbraio 2000. http://dx.doi.org/10.21236/ada383043.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Bingham, P. R., e K. W. Tobin. Direct to Digital Holography. Office of Scientific and Technical Information (OSTI), settembre 2007. http://dx.doi.org/10.2172/932949.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Bingham, P. R., e K. W. Tobin. Direct to Digital Holography. Office of Scientific and Technical Information (OSTI), giugno 2002. http://dx.doi.org/10.2172/940249.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Bingham, P. R., e K. W. Tobin. Direct to Digital Holography. Office of Scientific and Technical Information (OSTI), giugno 2003. http://dx.doi.org/10.2172/940257.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Bambha, Neal K., Justin R. Bickford, Jr Klett e Karl K. Two-dimensional Phase Unwrapping for Digital Holography. Fort Belvoir, VA: Defense Technical Information Center, settembre 2012. http://dx.doi.org/10.21236/ada570152.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Neifeld, Mark. Application of Compressive Sensing to Digital Holography. Fort Belvoir, VA: Defense Technical Information Center, maggio 2015. http://dx.doi.org/10.21236/ada616059.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Klett, Jr, Bambha Karl K., Bickford Neal e Justin. Holography at the U.S. Army Research Laboratory: Creating a Digital Hologram. Fort Belvoir, VA: Defense Technical Information Center, settembre 2012. http://dx.doi.org/10.21236/ada574840.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Guildenbecher, Daniel Robert. Developments in digital in-line holography enable validated measurement of 3D particle field dynamics. Office of Scientific and Technical Information (OSTI), dicembre 2013. http://dx.doi.org/10.2172/1121933.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Marron, Joseph C. Photon Noise in Digital Holographic Detection. Fort Belvoir, VA: Defense Technical Information Center, settembre 2008. http://dx.doi.org/10.21236/ada496179.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!