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Tesi sul tema "Imaging systems"
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1
Luo, Yuan. "Novel Biomedical Imaging Systems". Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/193907.
Testo completoAbstract (sommario):
The overall purpose of the dissertation is to design and develop novel optical imaging systems that require minimal or no mechanical scanning to reduce the acquisition time for extracting image data from biological tissue samples. Two imaging modalities have been focused upon: a parallel optical coherence tomography (POCT) system and a volume holographic imaging system (VHIS). Optical coherence tomography (OCT) is a coherent imaging technique, which shows great promise in biomedical applications. A POCT system is a novel technology that replaces mechanically transverse scanning in the lateral direction with electronic scanning. This will reduce the time required to acquire image data. In this system an array with multiple reduced diameter (15μm) single mode fibers (SMFs) is required to obtain an image in the transverse direction. Each fiber in the array is configured in an interferometer and is used to image one pixel in the transverse direction. A VHIS is based on volume holographic gratings acting as Bragg filters in conjunction with conventional optical imaging components to form a spatial-spectral imaging system. The high angular selectivity of the VHIS can be used to obtain two-dimensional image information from objects without the need for mechanical scanning. In addition, the high wavelength selectivity of the VHIS can provide spectral information of a specific area of the object that is being observed. Multiple sections of the object are projected using multiplexed holographic gratings in the same volume of the Phenanthrenquinone- (PQ-) doped Poly (methyl methacrylate) (PMMA) recording material.
2
O'Such, William R. "Information theoretic analysis of multi-stage communication/imaging systems /". Online version of thesis, 1988. http://hdl.handle.net/1850/10568.
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3
Olsson, CJ. "Imaging imagining actions". Doctoral thesis, Umeå : Section for Physiology, Department of Integrative Medical Biology, Umeå University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1910.
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4
Wang, Lulu. "Virtual imaging system". Click here to access this resource online, 2009. http://hdl.handle.net/10292/668.
Testo completoAbstract (sommario):
The main purpose of this research project was to implement a combination of computer graphics and processing to generate displays that will aid in the visualization of the colour rendering properties of a range of light sources, including the new generation of high-output LEDs (light emitting diodes) that are becoming widely adopted in general lighting service. The CIE (International Commission on Illumination) has developed a colour appearance model CIECAM02 for use in colour imaging and colour management, and this model is utilized in this work. This thesis describes the design and construction of a computer-based model that can be used as a research tool for the simulation and demonstration of the colour rendering properties of various artificial light sources. It is a comprehensive study of the colour models and measurement procedures currently in use in the lighting industry, as recommended by the CIE. This research project focused on the display of a set of surface colour patches as if they were illuminated by a specific light source, and the simultaneous display of two such sets to demonstrate the surface colour differences arising from the use of the two different light sources. A VIS (virtual imaging system) has been developed to display the colour properties of a series of test colour samples under different light sources. This thesis describes the computer models developed for the representation and display of surface colours in general, and colour rendering in particular. The designed system computes and displays the colour of each sample from a knowledge of the light-source spectrum and the spectral reflectance of each surface. It can simultaneously display the colours resulting from illumination by two different sources. In addition, the system computes the colour appearance differences for two sets of colours using the CIECAM02 colour appearance model. Subjective and objective tests were taken to validate the computed results. The VIS has been designed and implemented. It also has been tested by 21 observers and we believe that it will be a powerful research tool for the lighting industry, especially in relation to colour rendering.
5
Sukhija, Ruchi. "Document imaging application". CSUSB ScholarWorks, 2007. https://scholarworks.lib.csusb.edu/etd-project/3217.
Testo completoAbstract (sommario):
The purpose of this project was to develop a document imaging application. By scanning the documents into an electronic repository, medical staff will be able to more easily store and locate these records. To make the application user friendly and facilitate staff access to patient medical records, the application is wed-based and uses the Oracle Application Server to implement a multitiered model.
6
WOOD, LYNNETTE. "RESTORATION FOR SAMPLED IMAGING SYSTEMS". Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183994.
Testo completoAbstract (sommario):
Digital image restoration requires some knowledge of the degradation phenomena in order to attempt an inversion of that degradation. Typically, degradations which are included in the restoration process are those resulting from the optics and electronics of the imaging device. Occasionally, blurring caused by an intervening atmosphere, uniform motion or defocused optics is also included. Recently it has been shown that sampling, the conversion of the continuous output of an imaging system to a discrete array, further degrades or blurs the image. Thus, incorporating sampling effects into the restoration should improve the quality of the restored image. The system transfer function (the Fourier transform of the point spread function), was derived for the Landset Multi-Spectral Scanner and Thematic Mapper systems. Sampling effects were included, along with the relevant optical, instantaneous field of view and electronic filter data, in the system analysis. Using the system transfer function, a least squares (Wiener) filter was then derived. A Wiener filter requires the ratio of the power spectra of the scene and noise, which is often, for simplicity, assumed to be a constant over frequency. The restoration method used here includes models for the power spectra which are based on the study of several different types of Landsat scenes. The Wiener filter is then inverse Fourier transformed to find a restoration filter which is spatially windowed to suppress ringing. Qualitative and quantitative evaluations are made of the restored imagery. Comparisons are made to the approaches taken by other investigators, in particular, to one who has had success restoring the same type of imagery. It is found that the restoration method used here compares favorably with this previous work.
7
Feller, Alex J. "Instrument systems for imaging spectro-polarimetry". Göttingen Cuvillier, 2007. http://d-nb.info/988229595/04.
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Feller, Alex Jean. "Instrument systems for imaging spectro-polarimetry /". Göttingen : Cuvillier, 2008. http://d-nb.info/988229595/04.
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9
Blackband, S. J. "NMR imaging of liquid-solid systems". Thesis, University of Nottingham, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356019.
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10
Phan, Long N. 1976. "Automated rapid thermal imaging systems technology". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/75664.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 266-276).
A major source of energy savings occurs on the thermal envelop of buildings, which amounts to approximately 10% of annual energy usage in the United States. To pursue these savings, energy auditors use closed loop energy auditing processes that include infrared thermography inspection as an important tool to assess deficiencies and identify hot thermal gradients. This process is prohibitively expensive and time consuming. I propose fundamentally changing this approach by designing, developing, and deploying an Automated Rapid Thermal Imaging Systems Technology (ARTIST) which is capable of street level drive-by scanning in real-time. I am doing for thermal imaging what Google Earth did for visual imaging. I am mapping the world's temperature, window by window, house by house, street by street, city by city, and country by country. In doing so, I will be able to provide detailed information on where and how we are wasting energy, providing the information needed for sound economic and environmental energy policies and identifying what corrective measures can and should be taken. The fundamental contributions of this thesis relates to the ARTIST. This thesis will focus on the following topics: * Multi-camera synthetic aperture imaging system * 3D Radiometry * Non-radiometric infrared camera calibration techniques * Image enhancement algorithms - Hyper Resolution o Kinetic Super Resolution - Thermal Signature Identification - Low-Light Signal-to-Noise Enhancement using KSR
by Long N. Phan.
Ph.D.
11
Whitcombe, Michael James. "Red-sensitive imaging systems for holography". Thesis, Royal Holloway, University of London, 1987. http://repository.royalholloway.ac.uk/items/93c5198a-27d2-4c1d-ba1b-744bdc04fac0/1/.
Testo completoAbstract (sommario):
The primary objective of the work described in this thesis was to devise a red-sensitive photoresist imaging process for use in the replication of diffraction optics. In the introduction the chemistry of conventional photopolymer systems and photoresists used for holographic recording and the fabrication of diffraction gratings and diffracting optical elements is reviewed. The limitations of commercially available photoresist systems, particularly for applications requiring the use of red light are discussed. A polymer system has been investigated which could be imaged by photochemically generated free radicals, followed by a simple aqueous development procedure as required by the original specification. The polymer chosen for study was a copolymer of methyl methacrylate, methacrylic acid and 2-hydroxyethyl methacrylate. This was derivatized using methacryloyl chloride or methacrylic anhydride in order to introduce cross-linkable units to the polymer backbone. Polymers have been characterized by a number of techniques and the effect of varying composition on aqueous base solubility has been thoroughly studied. Various methods of derivatization have been employed. The ease of imaging has been found to be very sensitive to both the composition of the polymer and the extent of functionalization. High quality images have been obtained from this polymer using an organic solvent developer. Imaging experiments have been carried out on thin films of the photopolymer coated on glass using phenylazotriphenylmethane (PATM) as photoinitiator. Good images of 100 lines permillimetre (1 mm-1) have been recorded by contact printing. Interferometry has been used to demonstrate that interference patterns having 600 and 1200 1 mm-1 can be recorded using this polymer with PATM as initiator, exposed to an argon ion laser operating at 458nm. A number of two component photoredox initiator systems have been investigated, the light absorbing species of such systems being a dye such as methylene blue or certain cyanine dyes. The second component of these initiators may be an aryl sulphinate salt, a 1,3-diketone or some alkyl sulphides. The red light-initiated phatopolymerization of acrylamide has been demonstrated using some of these initiators and a low resolution photopolymer image has been recorded using Azure A and perinaphth-1,3-indandione as the photoinitiator system. This polymer can, in principle, produce images over a wide range of wavelengths depending on the nature of the initiator used.
12
Fan, Helen X. "Lens-coupled X-Ray Imaging Systems". Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/560833.
Testo completoAbstract (sommario):
Digital radiography systems are important diagnostic tools for modern medicine. The images are produced when x-ray sensitive materials are coupled directly onto the sensing element of the detector panels. As a result, the size of the detector panels is the same size as the x-ray image. An alternative to the modern DR system is to image the x-ray phosphor screen with a lens onto a digital camera. Potential advantages of this approach include rapid readout, flexible magnification and field of view depending on applications. We have evaluated lens-coupled DR systems for the task of signal detection by analyzing the covariance matrix of the images for three cases, using a perfect detector and lens, when images are affected by blurring due to the lens and screen, and for a signal embedded in a complex random background. We compared the performance of lens-coupled DR systems using three types of digital cameras. These include a scientific CCD, a scientific CMOS, and a prosumer DSLR camera. We found that both the prosumer DSLR and the scientific CMOS have lower noise than the scientific CCD camera by looking at their noise power spectrum. We have built two portable low-cost DR systems, which were used in the field in Nepal and Utah. We have also constructed a lens-coupled CT system, which included a calibration routine and an iterative reconstruction algorithm written in CUDA.
13
Pereira, Mauricio. "Ground Penetrating Radar Imaging and Systems". ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1139.
Testo completoAbstract (sommario):
The ASCE confers an overall D+ grade to American infrastructure, while the NAE lists the restoration and improvement of urban infrastructure as one of its grand engineering challenges for the 21st century, indicating that infrastructure renovation and development is a major challenge in the US. Furthermore, according to the UN World Urbanization Prospects, about 55% of the world's population lives in urban areas and this percentage is set to grow, especially in Africa and Asia. The growth of urban population poses challenges to the expansion of underground infrastructure, such as water, sewage, electricity and telecommunications. Localization and mapping of underground infrastructure are fundamental for infrastructure maintenance and development. Ground penetrating radar (GPR) is a remote sensing method capable of detecting subsurface assets that has been used in the localization and mapping of underground utilities. This thesis contributes improvements of GPR systems and imaging algorithms towards smarter infrastructure, specifically: Application of GPR imaging algorithm to improve GPR data readability and generate augmented reality (AR) content; Use of photogrammetric methods to improve GPR positioning for underground infrastructure localization and mapping.
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Braker, Benjamin M. "Spatial-spectral processing for imaging systems: Multibeam RF imaging and radar systems using spectral hole burning materials". Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3337181.
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Wu, Yuehao. "Compressive imaging and its applications". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 82 p, 2009. http://proquest.umi.com/pqdweb?did=1654493841&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Wittwer, Christian. "Fundamentals of digital imaging /". Online version of thesis, 1995. http://hdl.handle.net/1850/12257.
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GAMBINO, GIUSEPPE. "High-relaxivity systems and molecular imaging probes for Magnetic Resonance Imaging applications". Doctoral thesis, Università del Piemonte Orientale, 2014. http://hdl.handle.net/11579/46171.
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Dhillon, Ravinder. "Diagnostic imaging pathways /". Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0126.
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19
Asprey, Leonard Gregory. "An extension to system development methodologies for successful production imaging systems". Thesis, Queensland University of Technology, 2000.
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20
Yong, Ng Chee. "Multistatic radar imaging of moving targets". Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Dec/09Dec%5FNg_Chee.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Combat Systems Technology)--Naval Postgraduate School, December 2009.Thesis Advisor(s): Borden, Brett H. Second Reader: Pace, Phillip E. "December 2009." Description based on title screen as viewed on January 26, 2010. Author(s) subject terms: Radar imaging, moving targets, point spread function, ambiguity function. Includes bibliographical references (p.69). Also available in print.
21
Marín, Garcia Jordi. "Off-axis holography in microwave imaging systems". Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/285129.
Testo completoAbstract (sommario):
En las pasadas décadas, la investigación en tecnología de terahercios fue únicamente motivada por instrumentación para los campos de astrofísica y ciencias de la tierra. La principal línea de investigación de estos campos comprende la detección, identificación y mapeo mediante espectroscopia molecular de bandas de emisión y absorción de gases a baja presión. Este campo fue el mayor foco de desarrollo que permitió en primer lugar el desarrollo de instrumentación y tecnología a bandas de terahercios. En contraposición con su uso en campos científicos, la radiación de terahercios es una de las bandas de radio-frecuencia menos usadas en el ámbito comercial. La escasez de fuentes, sensores, sub-sistemas e instrumentos ha dificultado en los últimos años la proliferación de aplicaciones para un mayor público de consumo. La combinación de los últimos avances tecnológicos provenientes del campo científico, así como el descubrimiento de nuevas aplicaciones ha despertado de nuevo el interés por este campo, lo que ha supuesto un nuevo impulso económico para el desarrollo a estas frecuencias tanto a nivel público como privado.
Además del mencionado interés científico, la radiación de terahercios tiene características muy atractivas como por ejemplo una buena resolución espacial (comparada con menores frecuencias), penetración en materiales, capacidades espectroscópicas, absorción por humedad y niveles bajos de energía.
El trabajo desarrollado en esta tesis es parte de un proyecto de investigación a nivel nacional Español denominado Terasense. El interés principal de este proyecto es equipar las instituciones de investigación académicas con un nuevo conjunto de instrumentación y capacidades para poder desarrollar proyectos en el estado del arte en el campo de ondas milimétricas y sub-milimétricas.
El objetivo principal de esta tesis es explorar la viabilidad de sistemas de imagen en microondas y ondas milimétricas basados en técnicas holográficas mediante medidas de intensidad. En este documenta se estudia principalmente el uso de la técnica holográfica con referencia desplazada. No solo desde un punto de vista teórico sino especialmente desde un punto de vista experimental y práctico. En la tesis, diferentes experimentos y dispositivos son simulados, diseñados e implementados. La ida y vuelta entre software y hardware ha permitido la creación de un marco de desarrollo para el test de las diferentes técnicas de imagen estudiadas. El rango de frecuencia escogido como meta para este proyecto es la banda de frecuencia W (75-110 GHz). Sin embargo, muchos experimentos han sido desarrollados primero en banda X (8-12 GHz) para desarrollar la experiencia necesaria requerida para trabajar a frecuencias superiores en el rango de las ondas milimétricas.In past decades research in terahertz technology was solely motivated by instruments for topics such as astrophysics, planetary and earth sciences. Molecular line spectroscopy detection, identification and mapping of thermal emission and absorption signatures from low pressure gases comprised the main focus for most scientific requirements and motivated the development of terahertz instrumentation and technology. In spite of the scientific contributions of terahertz radiation, its spectrum is still one of the least used electromagnetics bands in commercial use. The unavailability of sources, sensors, sub-systems and instruments has been a cumbersome issue over the past years for its wide-spread use in commercial instrumentation. The combination of technological advances coming from the space-based community, along with the emergence of new applications, have managed to drive again the interest from both public and private sectors which has renown and skyrocketed the funding and research in terahertz applications. Aside from the aforementioned scientific interest, terahertz radiation has appealing characteristics such as good imaging resolution (as compared to lower frequencies), material penetration, spectroscopic capabilities, water absorption and low energy levels. The work of this thesis is part of a Spanish national research project called Terasense. The main focus of the project is to equip national academic research institutions with a completely new set of instrumentations and capabilities in order to advance towards the current state of the art in millimeter and sub-millimeter wave technologies. The main objective of this thesis is to explore the viability of microwave and millimeter-wave imaging systems based on intensity-only holographic techniques. This dissertation is mostly focused on the Off-Axis Holography technique. Not only from a theoretical perspective but specially from an actual implementation standpoint. In order to do so, different experimental setups and devices have been designed and manufactured. Iteration between hardware and software has created a framework for devising and testing different imaging techniques under consideration. The frequency range W-Band (75-110 GHz) has been chosen as the main goal for all systems under study, however different setups will first be constructed, characterized and tested at X-Band (8-12 GHz) in order to build up the expertise required to work at millimeter-wave frequencies.
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Brückner, Andreas [Verfasser]. "Microoptical multi aperture imaging systems / Andreas Brückner". Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2012. http://d-nb.info/1019969431/34.
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Mirani, Tejaswini N. "Optimal co-design of computational imaging systems". Ann Arbor, Mich. Proquest, 2005. http://proquest.umi.com/pqdweb?index=0&did=974441571&SrchMode=1&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1187816452&clientId=57025.
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McRobbie, Donald William. "Quantitative assessment of magnetic resonance imaging systems". Thesis, Imperial College London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312949.
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Demenikov, Mads. "Development and analyses of hybrid imaging systems". Thesis, Heriot-Watt University, 2010. http://hdl.handle.net/10399/2385.
Testo completoAbstract (sommario):
The aim of the work reported in this thesis is to analyse and develop hybrid imaging systems. Hybrid imaging systems are electro-optical imaging systems with optical elements implemented in the aperture-stop and digital post-image processing applied to the acquired image, jointly optimised for task-based imaging. Extended depth-of-field is one of the benefits that hybrid imaging systems provide. In particular, and as main objective of this thesis, we analyse and develop a hybrid and compact optical zoom lens with a single moving element and extended-depth-of-field. We show how a specific hybrid imaging technique can be used and implemented to miniaturise these zoom lenses such that they can be implemented in a mobile phone. We demonstrate that the implementation of a given phase mask and digital image restoration of the recorded images can imply two important trade-offs, namely image artifacts and noise amplification in the restored images. Image artifacts have not been given much attention in hybrid imaging systems. Despite of this, the image artifacts have probably been the main reason why no commercial products have been manufactured until now. In this thesis, we analyse for the first time the form of specific image artifacts, which imply that we are able to fully understand the physics of the artifacts. Based on the understanding, we develop a technique to remove the image artifacts. Furthermore, we develop a hybrid imaging system with adjustable noise amplification. Our original contributions to hybrid imaging techniques, which include the understanding of depth-of-field in various hybrid imaging systems (with and without sampling), understanding and development of a compact zoom lens with a single moving element, the understanding and removal of image artifacts, and development of a hybrid imaging system with adjustable noise amplification, will make the development of future and commercial hybrid imaging systems possible.
26
Lu, Nadine Chi-mei 1965. "Radiometric sensitivity comparisons of multispectral imaging systems". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277036.
Testo completoAbstract (sommario):
Multispectral imaging systems provide much of the basic data used by the land and ocean civilian remote sensing community. There are numerous multispectral imaging systems which have been and are being developed. A common way to compare the radiometric performance of these sensors is to examine their noise equivalent change in reflectance, NEDeltarho. The NEDeltarho of a sensor is the reflectance difference that is equal to the noise in the recorded signal. In order to directly compare the sensors, calculations of the parameter being compared need to have a common basis. This thesis compares the noise equivalent change in reflectance of seven different multispectral imaging systems (AVHRR, AVIRIS, ETM, HIRIS, MODIS-N, SPOT-1/HRV, and TM) for a set of three atmospheric conditions (continental aerosol with 23 km visibility, continental aerosol with 5 km visibility, and a Rayleigh atmosphere), five values of ground reflectance (0.01, 0.10, 0.25, 0.50, and 1.00), a nadir viewing angle, and a solar zenith angle of forty-five degrees.
27
Rideout, Robert Martin. "Coded imaging systems for X-ray astronomy". Thesis, University of Birmingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364854.
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Papadopoulos, Timoleon. "Inverse filtering for virtual acoustic imaging systems". Thesis, University of Southampton, 2006. https://eprints.soton.ac.uk/157421/.
Testo completoAbstract (sommario):
The research topic of this thesis is the use of inverse filtering for the design and implementation of two-channel virtual acoustic imaging systems that utilise loudspeakers. The basic objective of such systems is to invert the electroacoustic plant between the input to the loudspeakers and the output at the listener’s ears and hence make it possible for a pair of binaural signals to be locally reproduced at the position of the listener’s ears. As a starting point for the research presented, a previously introduced type of inverse filtering design is considered in which the inverse is implemented with FIR filters. The basic formulation of this design is described and a number of innovative points regarding its implementation are made. An experimental procedure is then formulated for the evaluation of the effectiveness of this inverse filtering design that is based on objective measurements of the inversion process. Unlike previously employed methods that are based on computer simulations or subjective experiments, the introduced experimental procedure is shown to be very efficient in isolating and exactly quantifying the effect on the accuracy of the inversion of a number of errors and approximations typically present in the implementation. A detailed evaluation is thus presented of the inverse filtering design at hand in realistic conditions of implementation. Subsequently, a novel method for the off-line implementation of the inverse filtering is presented that utilises recursive filters of lower order. In this method, the responses of the inverse filters are decomposed into two parts, one realisable in forward time and one in backward time. The effectiveness of this new method for the implementation of the inverse is tested and compared with a small selection of the objective evaluation results described above. Finally, an algorithm for the on-line implementation of the forward-backward inverse filtering is proposed and its computational cost is compared with the currently available frequency-domain block-processing filtering algorithms.
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Drake, Devin Robert. "Applications of laser scanning and imaging systems". [Gainesville, Fla.] : University of Florida, 2002. http://purl.fcla.edu/fcla/etd/UFE0000526.
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Elazhary, Tamer Mohamed Tawfik Ahmed Mohamed. "Generalized Pupil Aberrations Of Optical Imaging Systems". Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/347096.
Testo completoAbstract (sommario):
In this dissertation fully general conditions are presented to correct linear and quadratic field dependent aberrations that do not use any symmetry. They accurately predict the change in imaging aberrations in the presence of lower order field dependent aberrations. The definitions of the image, object, and coordinate system are completely arbitrary. These conditions are derived using a differential operator on the scalar wavefront function. The relationships are verified using ray trace simulations of a number of systems with varying degrees of complexity. The math is shown to be extendable to provide full expansion of the scalar aberration function about field. These conditions are used to guide the design of imaging systems starting with only paraxial surface patches, then growing freeform surfaces that maintain the analytic conditions satisfied for each point in the pupil. Two methods are proposed for the design of axisymmetric and plane symmetric optical imaging systems. Design examples are presented as a proof of the concept.
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Bailey, Vanessa Perry. "Adaptive Optics for Directly Imaging Planetary Systems". Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/577514.
Testo completoAbstract (sommario):
In this dissertation I present the results from five papers (including one in preparation) on giant planets, brown dwarfs, and their environments, as well as on the commissioning and optimization of the Adaptive Optics system for the Large Binocular Telescope Interferometer. The first three Chapters cover direct imaging results on several distantly-orbiting planets and brown dwarf companions. The boundary between giant planets and brown dwarf companions in wide orbits is a blurry one. In Chapter 2, I use 3–5 μm imaging of several brown dwarf companions, combined with mid-infrared photometry for each system to constrain the circum-substellar disks around the brown dwarfs. I then use this information to discuss limits on scattering events versus in situ formation. In Chapters 3 and 4, I present results from an adaptive optics imaging survey for giant planets, where the target stars were selected based on the properties of their circumstellar debris disks. Specifically, we targeted systems with debris disks whose SEDs indicated gaps, clearings, or truncations; these features may possibly be sculpted by planets. I discuss in detail one planet-mass companion discovered as part of this survey, HD 106906 b. At a projected separation of 650 AU and weighing in at 11 Jupiter masses, a companion such as this is not a common outcome of any planet or binary star formation model. In the remaining three Chapters, I discuss pre-commissioning, on-sky results, and planned work on the Large Binocular Telescope Interferometer Adaptive Optics system. Before construction of the LBT AO system was complete, I tested a prototype of LBTI's pyramid wavefront sensor unit at the MMT with synthetically-generated calibration files. I present the methodology and MMT on-sky tests in Chapter 5. In Chapter 6, I present the commissioned performance of LBTIAO. Optical imperfections within LBTI limited the quality of the science images, and I describe a simple method to use the adaptive optics system to correct for the science camera's optical aberrations. Finally, in Chapter 7, I discuss the status of a more sophisticated method for correcting these optical aberrations in LBTI.
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Shankar, Premchandra M. "Multiframe Superresolution Techniques For Distributed Imaging Systems". Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194713.
Testo completoAbstract (sommario):
Multiframe image superresolution has been an active research area for many years. In this approach image processing techniques are used to combine multiple low-resolution (LR) images capturing different views of an object. These multiple images are generally under-sampled, degraded by optical and pixel blurs, and corrupted by measurement noise. We exploit diversities in the imaging channels, namely, the number of cameras, magnification, position, and rotation, to undo degradations. Using an iterative back-projection (IBP) algorithm we quantify the improvements in image fidelity gained by using multiple frames compared to single frame, and discuss effects of system parameters on the reconstruction fidelity. As an example, for a system in which the pixel size is matched to optical blur size at a moderate detector noise, we can reduce the reconstruction root-mean-square-error by 570% by using 16 cameras and a large amount of diversity in deployment.We develop a new technique for superresolving binary imagery by incorporating finite-alphabet prior knowledge. We employ a message-passing based algorithm called two-dimensional distributed data detection (2D4) to estimate the object pixel likelihoods. We present a novel complexity-reduction technique that makes the algorithm suitable even for channels with support size as large as 5x5 object pixels. We compare the performance and complexity of 2D4 with that of IBP. In an imaging system with an optical blur spot matched to pixel size, and four 2x2 undersampled LR images, the reconstruction error for 2D4 is 300 times smaller than that for IBP at a signal-to-noise ratio of 38dB.We also present a transform-domain superresolution algorithm to efficiently incorporate sparsity as a form of prior knowledge. The prior knowledge that the object is sparse in some domain is incorporated in two ways: first we use the popular L1 norm as the regularization operator. Secondly we model wavelet coefficients of natural objects using generalized Gaussian densities. The model parameters are learned from a set of training objects and the regularization operator is derived from these parameters. We compare the results from our algorithms with an expectation-maximization (EM) algorithm for L1 norm minimization and also with the linear minimum mean squared error (LMMSE) estimator.
33
PIAZZA, SIMONLUCA. "Advanced optical systems for imaging and fabrication". Doctoral thesis, Università degli studi di Genova, 2018. http://hdl.handle.net/11567/932054.
Testo completo
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Staley, Timothy. "Lucky imaging : beyond binary stars". Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607953.
Testo completo
35
Teo, Beng Koon William. "Radar imaging for moving targets". Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Jun/09Jun%5FTeo.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Applied Physics)--Naval Postgraduate School, June 2009.Thesis Advisor(s): Borden, Brett H. "June 2009." Description based on title screen as viewed on July 14, 2009. Author(s) subject terms: radar imaging, moving targets, point spread function, ambiguity function. Includes bibliographical references (p. 73-75). Also available in print.
36
Tsang, Kwong Man. "A real-time acoustic imaging system using digital signal processor array". HKBU Institutional Repository, 1995. http://repository.hkbu.edu.hk/etd_ra/49.
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Ata, Ali. "Wireless IR image transfer system for autonomous vehicles". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FAta.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Applied Physics)--Naval Postgraduate School, December 2003.Thesis advisor(s): Gamani Karunasiri, Richard M. Harkins. Includes bibliographical references (p. 31). Also available online.
38
Tingstad, James Scott 1962. "Design of an advanced I.R. catadioptric optical system". Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276689.
Testo completoAbstract (sommario):
This thesis explains and develops the design of a compact 3-5μm catadioptric optical imaging system. This system is intended for use with a two-dimensional array detector that replaces the need for the scan mirrors of a traditional FLIR system. This design also illustrates the complete optical design process. From the basic system requirements, to a complete design with consideration to such items as assembly and alignment, cost, and maintaining focus for a change in the environmental temperature.
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Wild, Walter James. "Gamma-ray imaging probes". Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184331.
Testo completoAbstract (sommario):
External nuclear medicine diagnostic imaging of early primary and metastatic lung cancer tumors is difficult due to the poor sensitivity and resolution of existing gamma cameras. Nonimaging counting detectors used for internal tumor detection give ambiguous results because distant background variations are difficult to discriminate from neighboring tumor sites. This suggests that an internal imaging nuclear medicine probe, particularly an esophageal probe, may be advantageously used to detect small tumors because of the ability to discriminate against background variations and the capability to get close to sites neighboring the esophagus. The design, theory of operation, preliminary bench tests, characterization of noise behavior and optimization of such an imaging probe is the central theme of this work. The central concept lies in the representation of the aperture shell by a sequence of binary digits. This, coupled with the mode of operation which is data encoding within an axial slice of space, leads to the fundamental imaging equation in which the coding operation is conveniently described by a circulant matrix operator. The coding/decoding process is a classic coded-aperture problem, and various estimators to achieve decoding are discussed. Some estimators require a priori information about the object (or object class) being imaged; the only unbiased estimator that does not impose this requirement is the simple inverse-matrix operator. The effects of noise on the estimate (or reconstruction) is discussed for general noise models and various codes/decoding operators. The choice of an optimal aperture for detector count times of clinical relevance is examined using a statistical class-separability formalism.
40
Bobiak, John Peter. "Raman and Infrared Imaging of Dynamic Polymer Systems". Case Western Reserve University School of Graduate Studies / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=case1133472157.
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Chan, Wai-san. "Design and analysis of integrated computational imaging systems". Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38960357.
Testo completo
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Zelinski, Michael E. "A segmented aperture space telescope modeling tool and its application to remote sensing as understood through image quality and image utility /". Online version of thesis, 2009. http://hdl.handle.net/1850/11658.
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Yau, Chin-ko. "Superresolution imaging models and algorithms /". Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/HKUTO/record/B3955904X.
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44
游展高 e Chin-ko Yau. "Superresolution imaging: models and algorithms". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B3955904X.
Testo completo
45
Bobiak, John Peter. "Raman and FTIR imaging of dynamic polymer systems". online version, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1133472157.
Testo completo
46
Vlašín, Ondrej. "Spectroscopy and confocal imaging of complex ferroic systems". Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/133353.
Testo completoAbstract (sommario):
En las nuevas aplicaciones basadas en sistemas ferroicos a menudo
se consideran las paredes de dominio como portadores de la información.
Asimismo, la necesidad de satisfacer la ley de Moore requiere
una reducción drástica de las dimensiones de los dispositivos a comercializar.
Aunque ya existen métodos para estudiar la dinámica
de los dominios a nanoescala, éstos son muy lentos y caros, además
es muy complicado medir las propiedades magnéticas y eléctricas simultáneamente.
Esto crea la necesidad de un método intermedio que
ofrezca resolución lateral submicrométrica y cortos tiempos de medición
y que, al mismo tiempo, proporcione suficiente información
sobre todas las propiedades ferroicas de un sistema.
Para solucionar este problema, hemos desarrollado varios métodos
ópticos que amplían las posibilidades de caracterización multiferroica.
Por un lado, hemos desarrollado un montaje experimental
magneto-óptico Kerr que permite trabajar bajo campos eléctricos aplicados
in-situ en un rango de frecuencias ajustables. Mediante esta
aproximación experimental, hemos podido separar y cuantificar diferentes
contribuciones al acoplamiento magnetoeléctrico (mediado
por tensión superficial y/o por efectos de superficie) y hemos podido
analizar su dinámica específica por separado. Por otro lado, hemos
podido obtener una cartografía directa del acoplamiento magnetoeléctrico
con una resolución lateral submicrónica, mediante al desarrollo
de un microscopio confocal sensible a la polarización de la luz.
En experimentos realizados en BTO / LSMO se observaron cambios
inducidos por un campo magnético en la respuesta ferroeléctrica en
torno al 50% en promedio, con variaciones de hasta un 20 %.
Finalmente, hemos estudiado r el origen del aumento de la respuesta
magneto-óptica a frecuencias resonantes con plasmones en cristales
magnetofotónicos. Estos resultados abren nuevas perspectivas en dispositivos
basados en la física de plasmones, con aplicaciones en comunicaciones
ópticas y en detección. En esta línea, hemos desarrollado
un marco teórico unificado que permite modelar las señales magnetoópticas
de soluciones coloidales en un rango amplio de frecuencias
en el visible. El modelo que proponemos muestra una excelente concordancia
con los datos medidos experimentalmente en soluciones
coloidales de nanopartículas de níquel en hexano y en tolueno, utilizando
solamente las propiedades ópticas tabuladas de los materiales,
sin ajustar ningún parámetro. Estos resultados abren nuevas perspectivas
en materiales compuestos metal/dieléctrico, para dispositivos
innovadores basados en plasmones, que explotan la polarización de
la luz en vez de los cambios en reflectancia óptica.New applications of ferroic systems often consider domain wall as carrier of information. Understanding of the nature of domain structure and its dynamics is therefore essential. At the same time the omnipresent need of keeping up with Moore law demands the dimensions of commercialized devices to decrease drastically. Hence the resolution of classical optical Kerr microscopy does not suffice anymore. Methods for studying domain dynamics at nanoscale are available, but are very time consuming and expensive. It’s extremely complicated to measure both magnetic and electric properties simultaneously. This creates a need for an intermediate method that offers sub-micron lateral resolution and short measurement times, yet produces enough information about all ferroic properties of a system. To address this issue we developed several optical methods that expand the possibilities of multiferroic characterization. An electric field frequency spectrum magneto-optical Kerr effect setup allows for an effective separation and quantification of surface and strain mediated magnetoelectric coupling effects as demonstrated on Co/ lead zirconate titanate (PZT) ferroic multilayers. Direct electro-magnetic domain mapping with sub-micron lateral resolution was made possible with cryostat ready polarization sensitive confocal microscope. Magnetic field induced changes in ferro-electric response around 50% with 20% variations were observed on barium titanate (BTO)/ lanthanum strontium manganite (LSMO) structure. Furthermore, enhancements to magneto-optical Kerr-effect (MOKE) spectroscope enabled study of the origin of magneto-optical enhancement at plasmonic frequencies in magneto-photonic crystals. This paves the way to plasmon-devices with optimal performance for applications in optical communications and sensing. In this line, we developed a unified theoretical frame for modeling of both saturating and non-saturating magneto-optical effects in diluted colloidal dispersions of magnetic nanoparticles. The model shows remarkably good agreement with experimental data obtained from nickel nanoparticles in hexane and toluene using only tabulated data and no fitting. Hence we can envision the use of optimized hybrid metal/ dielectric composites as platforms for new optical devices and especially for innovative plasmon-based sensors exploiting light polarization instead of reflectance.
47
Fredriksson, Jesper. "Evolutionary Development of Brain Imaging Meta-analysis Systems". Licentiate thesis, KTH, Numerical Analysis and Computer Science, NADA, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1440.
Testo completo
48
Zeitler, Armin. "Investigation of mm-wave imaging and radar systems". Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00832647.
Testo completoAbstract (sommario):
In the last decade, microwave and millimeter-wave systems have gained importance in civil and security applications. Due to an increasing maturity and availability of circuits and components, these systems are getting more compact while being less expensive. Furthermore, quantitative imaging has been conducted at lower frequencies using computational intensive inverse problem algorithms. Due to the ill-posed character of the inverse problem, these algorithms are, in general, very sensitive to noise: the key to their successful application to experimental data is the precision of the measurement system. Only a few research teams investigate systems for imaging in the W-band. In this manuscript such a system is presented, designed to provide scattered field data to quantitative reconstruction algorithms. This manuscript is divided into six chapters. Chapter 2 describes the theory to compute numerically the scattered fields of known objects. In Chapter 3, the W-band measurement setup in the anechoic chamber is shown. Preliminary measurement results are analyzed. Relying on the measurement results, the error sources are studied and corrected by post-processing. The final results are used for the qualitative reconstruction of all three targets of interest and to image quantitatively the small cylinder. The reconstructed images are compared in detail in Chapter 4. Close range imaging has been investigated using a vector analyzer and a radar system. This is described in Chapter 5, based on a future application, which is the detection of FOD on airport runways. The conclusion is addressed in Chapter 6 and some future investigations are discussed.
49
Chan, Wai-san, e 陳慧珊. "Design and analysis of integrated computational imaging systems". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38960357.
Testo completo
50
Nadeau, Valerie J. "Fluorescence imaging and spectroscopy systems for cancer diagnostics". Thesis, University of Glasgow, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269513.
Testo completo