Tesis sobre el tema "Illumination analysis"
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Bales, Michael Ryan. "Illumination compensation in video surveillance analysis". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39535.
Texto completoNoel, Laurent. "Discrete shape analysis for global illumination". Thesis, Paris Est, 2015. http://www.theses.fr/2015PESC1130/document.
Texto completoNowadays, computer generated images can be found everywhere, through a wide range of applications such as video games, cinema, architecture, publicity, artistic design, virtual reality, scientific visualization, lighting engineering, etc. Consequently, the need for visual realism and fast rendering is increasingly growing. Realistic rendering involves the estimation of global illumination through light transport simulation, a time consuming process for which the convergence rate generally decreases as the complexity of the input virtual 3D scene increases. In particular, occlusions and strong indirect illumination are global features of the scene that are difficult to handle efficiently with existing techniques. This thesis addresses this problem through the application of discrete shape analysis to rendering. Our main tool is a curvilinear skeleton of the empty space of the scene, a sparse graph containing important geometric and topological information about the structure of the scene. By taking advantage of this skeleton, we propose new methods to improve both real-time and off-line rendering methods. Concerning real-time rendering, we exploit geometric information carried by the skeleton for the approximation of shadows casted by a large set of virtual point lights representing the indirect illumination of the 3D scene. Regarding off-line rendering, our works focus on algorithms based on path sampling, that constitute the main paradigm of state-of-the-art methods addressing physically based rendering. Our skeleton leads to new efficient path sampling strategies guided by topological and geometric features. Addressing the same problem, we also propose a sampling strategy based on a second tool from discrete shape analysis: the opening function of the empty space of the scene, describing the local thickness of that space at each point. Our contributions demonstrate improvements over existing approaches and clearly indicate that discrete shape analysis offers many opportunities for the development of new rendering techniques
Zhao, Shuyan. "Face analysis under near infrared illumination". Göttingen Cuvillier, 2008. http://d-nb.info/990811492/04.
Texto completoMartinkauppi, B. (Birgitta). "Face colour under varying illumination - analysis and applications". Doctoral thesis, University of Oulu, 2002. http://urn.fi/urn:isbn:9514267885.
Texto completoPAULA, MARCUS VINICIUS DE. "SHADOW OF ILLUMINATION: AN ICONOLOGICAL ANALYSIS OF ILLEGIBILITY". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=11785@1.
Texto completoEste trabalho utiliza o método iconológico de análise desenvolvido por W.J.T. Mitchell para expandir a noção de iluminura e dissolver a oposição entre legível e ilegível. Na primeira parte desta tese são analisados e definidos os mecanismos de leitura da iluminura e suas relações com as convenções da legibilidade e da ilegibilidade. Na segunda parte aborda-se essa mesma questão por meio de outra perspectiva, que envolve as transformações gráficas sofridas pelas páginas dos jornais a partir da virada do século XIX para o século XX.
This work uses the iconological method of analysis developed by W.J.T. Mitchell to expand on the notion of illlumination and to break up the antagonism between the legibel and the illegible.In the first part of this thesis the mechanisms of reading illumination and their relation with the conventions of legibility and illegibility are analized and defined. In the second part, this same subject is approached from another perspective wich has envolved with the graphic transformation of newspaper pages at the end of the 19th Century end the beginning of the 20th Century.
Agrawal, Amit Kumar. "Scene analysis under variable illumination using gradient domain methods". College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3624.
Texto completoThesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Nillius, Peter. "Image Analysis using the Physics of Light Scattering". Doctoral thesis, KTH, Numerical Analysis and Computer Science, NADA, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3780.
Texto completoAny generic computer vision algorithm must be able to copewith the variations in appearance of objects due to differentillumination conditions. While these variations in the shadingof a surface may seem a nuisance, they in fact containinformation about the world. This thesis tries to provide anunderstanding what information can be extracted from theshading in a single image and how to achieve this. One of thechallenges lies in finding accurate models for the wide varietyof conditions that can occur.
Frequency space representations are powerful tools foranalyzing shading theoretically. Surfaces act as low-passfilters on the illumination making the reflected lightband-limited. Hence, it can be represented by a finite numberof components in the Fourier domain, despite having arbitraryillumination. This thesis derives a basis for shading byrepresenting the illumination in spherical harmonics and theBRDF in a basis for isotropic reflectance. By analyzing thecontributing variance of this basis it is shown how to createfinite dimensional representations for any surface withisotropic reflectance.
The finite representation is used to analytically derive aprincipal component analysis (PCA) basis of the set of imagesdue to the variations in the illumination and BRDF. The PCA isperformed model-based so that the variations in the images aredescribed by the variations in the illumination and the BRDF.This has a number of advantages. The PCA can be performed overa wide variety of conditions, more than would be practicallypossible if the images were captured or rendered. Also, thereis an explicit mapping between the principal components and theillumination and BRDF so that the PCA basis can be used as aphysical model.
By combining a database of captured illumination and adatabase of captured BRDFs a general basis for shading iscreated. This basis is used to investigate materialclassification from a single image with known geometry butarbitrary unknown illumination. An image is classified byestimating the coecients in this basis and comparing them to adatabase. Experiments on synthetic data show that materialclassification from reflectance properties is hard. There aremis-classifications and the materials seem to cluster intogroups. The materials are grouped using a greedy algorithm.Experiments on real images show promising results.
Keywords:computer vision, shading, illumination,reflectance, image irradiance, frequency space representations,spherical harmonics, analytic PCA, model-based PCA, materialclassification, illumination estimation
Singh, Gurprit. "Sampling and Variance Analysis for Monte Carlo Integration in Spherical Domain". Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10121/document.
Texto completoThis dissertation introduces a theoretical framework to study different sampling patterns in the spherical domain and their effects in the evaluation of global illumination integrals. Evaluating illumination (light transport) is one of the most essential aspect in image synthesis to achieve realism which involves solving multi-dimensional space integrals. Monte Carlo based numerical integration schemes are heavily employed to solve these high dimensional integrals. One of the most important aspect of any numerical integration method is sampling. The way samples are distributed on an integration domain can greatly affect the final result. For example, in images, the effects of various sampling patterns appear in the form of either structural artifacts or completely unstructured noise. In many cases, we may get completely false (biased) results due to the sampling pattern used in integration. The distribution of sampling patterns can be characterized using their Fourier power spectra. It is also possible to use the Fourier power spectrum as input, to generate the corresponding sample distribution. This further allows spectral control over the sample distributions. Since this spectral control allows tailoring new sampling patterns directly from the input Fourier power spectrum, it can be used to improve error in integration. However, a direct relation between the error in Monte Carlo integration and the sampling power spectrum is missing. In this work, we propose a variance formulation, that establishes a direct link between the variance in Monte Carlo integration and the power spectra of both the sampling pattern and the integrand involved. To derive our closed-form variance formulation, we use the notion of homogeneous sample distributions that allows expression of error in Monte Carlo integration, only in the form of variance. Based on our variance formulation, we develop an analysis tool that can be used to derive theoretical variance convergence rates of various state-of-the-art sampling patterns. Our analysis gives insights to design principles that can be used to tailor new sampling patterns based on the integrand
Lee, Jinho. "Synthesis and analysis of human faces using multi-view, multi-illumination image ensembles". Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1133366279.
Texto completoStevenson, Brady Roos. "Analysis of Near-Infrared Phase Effects on Biometric Iris Data". BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/1299.
Texto completoWallenberg, Marcus. "A Single-Camera Gaze Tracker using Controlled Infrared Illumination". Thesis, Linköping University, Department of Electrical Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-17398.
Texto completoGaze tracking is the estimation of the point in space a person is “looking at”. This is widely used in both diagnostic and interactive applications, such as visual attention studies and human-computer interaction. The most common commercial solution used to track gaze today uses a combination of infrared illumination and one or more cameras. These commercial solutions are reliable and accurate, but often expensive. The aim of this thesis is to construct a simple single-camera gaze tracker from off-the-shelf components. The method used for gaze tracking is based on infrared illumination and a schematic model of the human eye. Based on images of reflections of specific light sources in the surfaces of the eye the user’s gaze point will be estimated. Evaluation is also performed on both the software and hardware components separately, and on the system as a whole. Accuracy is measured in spatial and angular deviation and the result is an average accuracy of approximately one degree on synthetic data and 0.24 to 1.5 degrees on real images at a range of 600 mm.
Kricke, Ralph [Verfasser]. "Lip Motion Analysis for a Person Authentication System under Near Infrared Illumination / Ralph Kricke". München : Verlag Dr. Hut, 2011. http://d-nb.info/1015608108/34.
Texto completoBari, Daniele. "Characterization and Reliability of Dye-sensitized Solar Cells: Temperature, Illumination, and Bias Effects". Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3423712.
Texto completoDye-sensitized solar cells (DSC) hanno recentemente dimostrato di essere un’alternativa a basso costo al fotovoltaico inorganico e in futuro non lontano potrebbero detenere una quota di mercato notevole. Tuttavia, i problemi di affidabilità devono essere risolti per migliorare la competitività di questa nuova tecnologia. La presente tesi tratta la caratterizzazione e lo studio affidabilità di DSC al fine di avere un quadro completo circa l'efficienza, la stabilità e i meccanismi di degradazione nelle DSC, al fine di promuovere questi dispositivi come un nuova fonte di energia rispettando inoltre le normative della Comunità Europea. Da quando Michael Grätzel nel 1991 avanzò il concetto di materiali sensibilizzati e semiconduttori nanoporosi, dye-sensitized solar cells hano attirato l'interesse di molti ricercatori universitari e di aziende operanti nel fotovoltaico, aprendo così la strada al fotovoltaico di terza generazione. Risultati notevoli nella sintesi di cromofori sempre più pancromatici e nella fabbricazione di semiconduttori ad ampio bad-gap, consentono a fisici, chimici ed ingegneri di produrre DSC sempre più efficienti e affidabili. Al momento di questa tesi, l’efficienza delle DSC ha raggiunto il 13.4% il che consente loro di competere con i sistemi fotovoltaici inorganici convenzionali in termini di costi di produzione e complessità materiale, in particolar modo in quelle applicazioni in cui il rapporto efficienza costi di produzione deve essere massimizzato. Ci sono diverse applicazioni in cui le prestazioni di queste celle solari foto-elettrochimiche sono già sufficienti: applicazioni outdoor, come le finestre degli edifici e la copertura delle serre; applicazioni indoor come finestre, strutture di decorazione, e le vetrate dei negozi. Nonostante i vantaggi, molti problemi tecnologici e di affidabilità devono ancora essere risolti. Alcune delle problematiche sono: stabilità delle caratteristiche elettriche, incapsulamento, effetti dei fattori ambientali (ad esempio l'esposizione ai raggi UV per applicazioni esterne), l'umidità, la temperatura elevata, l’incremento del lifetime. Un'intensa attività di ricerca è portata avanti da ricercatori di tutto il mondo per capire l'affidabilità e le cause di instabilità delle DSC: questi sforzi coinvolgono lo studio di molti aspetti fisici e chimici compresi gli effetti nell’uso di diversi materiali, strutture, morfologie, coloranti, elettroliti, contro-elettrodi, fabbricazione in condizioni e presenza di ossigeno e di umidità. I metodi di caratterizzazione utilizzati per caratterizzare celle solari silicon-based non possono essere utilizzati "as is" per le DSC senza considerare la diversa natura delle DSC rispetto alle celle silicon-based. Partendo dalla conoscenza nella caratterizzazione di celle solari silicon-based e da un background in elettrochimica, abbiamo attentamente trasposto i metodi di caratterizzazione alle DSC. L'accesso a tutti i dettagli tecnologici delle DSC sono disponibili grazie alla collaborazione con l'Università di Roma "Tor Vergata". Abbiamo sviluppato una procedura di misura che permette di definire gli standard per la caratterizzazione di dye-sensitized solar cells. Questa procedura si basa su misure DC e spettroscopia di impedenza (EIS), dove quest'ultima tecnica proviene dall’elettrochimica. Questa tecnica permette di caratterizzare le interfacce presenti nelle DSC e di identificare quali interfacce stanno degradando durante gli stress accelerati. Questo set di misure fornisce una descrizione completa delle celle e del loro comportamento durante gli stress accelerati. La caratterizzazione e lo studio di affidabilità viene esguita illuminando le celle con un simulatore solare AM 1.5, dove il suo spettro si estende dagli UV sino al lontano IR. Come fonte di illuminazione alternativa, abbiamo progettato una sorgente di luce monocromatica basata su LED per illuminare le celle solari durante la caratterizzazione. Abbiamo progettato l'illuminatore nonché la circuiteria di pilotaggio. Abbiamo scoperto che queste sorgenti monocromatiche eccitano una porzione diversa dello spettro di assorbimento delle celle: in particolare, la porzione dello spettro eccitata è funzione della lunghezza d'onda della sorgente di illuminazione. Ciò permette di avere ulteriori informazioni sull’efficienza e sulla degradazione delle DSC. Inoltre, durante gli aging test, abbiamo notato che la cinetica di degradazione della tensione di circuito aperto, della corrente di corto circuito, dell'efficienza, e del fill factor, cambia se la caratterizzazione viene eseguita con diverse lunghezze d'onda della sorgente di illuminazione. Questo fatto sottolinea che la caratterizzazione effettuata con luce monocromatica potrebbe dare ulteriori informazioni sul meccanismo di degradazione che causa il degrado delle DSC. Per avere un quadro sull’affidabilità delle DSC, abbiamo effettuato molti ageing test, con altrettante fonti di illuminazione o in generale di stress. Tutte queste prove sono state effettuate indoor. Abbiamo studiato il degrado delle celle sottoposte a stress accelerati con diverse condizioni di illuminazione e il ruolo della temperatura nel degrado delle celle. Questo studio è stato possbile effettuando stress accelerati per mezzo di: simulatore solare AM1.5, camere climatiche, illuminatore a LED bianco, illuminatore UV, e driver in corrente per gli constant current stress (CCS). Poiché le DSC si scaldano durante l'esposizione alla luce solare e quindi la loro temperatura interna aumenta, abbiamo cercato di capire il ruolo della temperatura nella degradazione delle DSC. Abbiamo dimostrato che la sola temperatura può incidere fortemente sul tasso di degradazione delle DSC riducendo le prestazioni complessive delle celle; inoltre, abbiamo dimostrato che la temperatura ha un duplice impatto sulle prestazioni delle celle. Una temperatura moderata induce un processo di annealing: migliora le prestazioni del colorante probabilmente ristabilendo alcuni legami liberi o deboli all'interfaccia semiconduttore trasparente/colorante o tra le molecole di colorante. D'altra parte, a temperature elevate o per tempi più lunghi di stress, indipendentemente dal livello di temperatura, la temperatura riduce fortemente le prestazioni DSC nonché il lifetime. Per capire gli effetti indotti da esposizione alla luce solare, abbiamo effettuato stress ottici accelerati per mezzo di un simulatore solare AM 1.5. Inoltre, abbiamo confrontato la cinetica di degradazione dei parametri DC misuratu durante gli stress ottici e termici. Il responsabile della degradazione durante lo stress termico o ottico è la formazione di difetti e di specie chimiche all’interfaccia tra il semiconduttore trasparente/dye/elettrolita i quali riducono la capacità di trasferimento di carica all'interfaccia e la migrazione degli ioni attraverso l’elettrolita. Durante gli stress ottici, abbiamo osservato una chiara differenza tra la cinetica di degradazione della tensione di circuito aperto e la cinetica di degradazione della corrente di corto circuito: quest'ultimo solitamente presenta una fase di inversione di tendenza durante gli stress ottici. La fase di inversione di tendenza è fortemente dipendente dalla intensità di illuminazione utilizzata durante lo stress accelerato: maggiore è il livello di illuminazione, minore è la durata della fase di inversione di tendenza. La degradazione della cella è più veloce con livelli di illuminazione più elevati probabilmente dovuta all'aumento della temperatura di interfaccia, come confermato anche dagli stress termici puri. L’elevato rapporto efficienza-peso consente alle DSC di poter essere utilizzate come fonte di energia in applicazioni spaziali. Per indagare gli effetti di fotoni ad alta energia (presenti anche a livello del suolo) sulle DSC, abbiamo effettuato stress accelerati utilizzando una fonte di illuminazione UV. Abbiamo progettato e assemblato un illuminatore a raggi UV, così come il circuito di pilotggio. Abbiamo scoperto che l'esposizione ai raggi UV ha effetti negativi su DSC e il principale responsabile della degradazione delle celle durante l'esposizione ai raggi UV è il bleaching dell'elettrolita (scolorimento dell’elettrolita). Vale la pena notare che il dye sembra avere un ruolo secondario nella degradazione della cella come è stato dimostrato. Per quanto riguarda le DSC studiate in questa tesi, si consiglia di adottare alcune soluzioni per evitare il bleaching dell’elettrolita. Il filtraggio UV e un buon incapsulamento potrebbero portare benefici per un funzionamento affidabile nel tempo, anche se potenzialmente vanno contro il peso contenuto e la naturale trasparenza delle DSC. Alta efficienza anche a basse intensità di illuminazione o con luce diffusa permette alle DSC di essere prese in considerazione per applicazioni indoor. Abbiamo effettuato ageing test tramite LED bianchi ad alta potenza e abbiamo confrontato la cinetica di degradazione dei parametri DC così come l’evoluzione dell’impedenza (EIS). Queste caratteristiche sono state misurate illuminando le celle sia con simulatore solare AM 1.5 che con un illuminatore a LED bianchi. Congiuntamente allo studio di affidabilità, abbiamo proposto un sistema di illuminazione basato su LED bianchi come un'alternativa economica e versatile ai costosi simulatori solari AM 1.5. Abbiamo progettato l'illuminatore basato su LED bianchi cosi come il suo circuito di pilotaggio. Dai risultati raccolti durente gli stress, abbiamo scoperto che l'esposizione alla luce bianca porta al degrado delle prestazioni delle DSC. Anche se lo spettro bianco non ha componente UV, le molecole del dye non sono più in grado di assorbire lunghezze d'onda nella regione UV. Confrontando le caratteristiche (DC ed EIS) misurate con il simulatore solare a LED bianchi e con il simulatore solare AM 1.5, abbiamo mostrato e provato che quest'ultimo fornisce più informazioni rispetto al primo. Dal punto di vista pannello solare, alcune DSC potrebbero incorrere in guasti o essere ombreggiate durante l'esposizione solare. Tale situazione potrebbe verificarsi nel caso in cui una cella/stringa di un pannello solare non sia funzionante oppure sia in ombra e non siano state adottate soluzioni atte a prevenirne una condizione operativa non convenzionale (ovvero non sono presenti diodi di by-pass o blocking diode). Per esaminare questa condizione reale non banale, abbiamo progettato e assemblato diversi driver di corrente e abbiamo eseguito molti constant current stress (CCS). I CCS eseguiti sono di due tipi: postive CCS e negative CCS. Il primo prevede di polarizzare la cella in modo tale che la corrente scorra nello verso che scorre quando esposta a luce solare, cioè in condizione standard di funzionamento; negative CCS, prevede di polarizzare la cella nel senso opposto al positive CCS. Durante gli stress le DSC vengono mantenute al buio, per evitare effetti dovuti all’illuminazione. Dai dati raccolti durante i due tipi di CCS, si è potuto envincere che entrambe portano ad una degradazione delle performance della cella e che all’aumentare del modulo della corrente di stress diminuisce il tempo di vita della DSC. Osservando le caratteristiche DC delle celle stressate, positive e negative CCS degradano le DSC in maniera diversa: i primi portano ad un degrado lento e costante della cella, i secondi, apparentemente non degradano le celle in maniera significativa all’inizio dello stress, ma ne causano un’improvvisa e rapida degradazione (sudden failure) dopo diverse ore. L’istante in cui si verifica il sudden failure della DSC è funzione dell’intensità della corrente di stress. Abbiamo mostrato che durante i positive CCS, la composizione elettrolita cambia, abbassando la dark current della cella solare, mentre i negative CCS portano alla degradazione del contro-elettrodo, accelerandone la corrosione da parte dell’elettrolita. Inoltre, abbiamo dimostrato che la maggior della degradazione avviene alle interfacce in cui gli elettroni sono emessi durante lo stress. I risultati ottenuti, dimostrano che i CCS hanno effetti irreversibili sulle prestazioni elettriche delle DSC e che alcune soluzioni circuitali devono essere adottate allo scopo di prevenire inoppurtune condizioni di funzionamento delle celle.
Luo, Ming. "Optical Analysis and Opto-Mechanical Design for Miniaturized Laser Illumination Module in 3D Areal Mapper". Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/33169.
Texto completoMaster of Science
Carvalho, Tiago José de 1985. "Illumination inconsistency sleuthing for exposing fauxtography and uncovering composition telltales in digital images". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275519.
Texto completoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação
Made available in DSpace on 2018-08-25T12:33:40Z (GMT). No. of bitstreams: 1 Carvalho_TiagoJosede_D.pdf: 74759719 bytes, checksum: dc371f3262b700f91afa5e0269df1e05 (MD5) Previous issue date: 2014
Resumo: Antes tomadas como naturalmente genuínas, fotografias não mais podem ser consideradas como sinônimo de verdade. Com os avanços nas técnicas de processamento de imagens e computação gráfica, manipular imagens tornou-se mais fácil do que nunca, permitindo que pessoas sejam capazes de criar novas realidades em minutos. Infelizmente, tais modificações, na maioria das vezes, têm como objetivo enganar os observadores, mudar opiniões ou ainda, afetar como as pessoas enxergam a realidade. Assim, torna-se imprescindível o desenvolvimento de técnicas de detecção de falsificações eficientes e eficazes. De todos os tipos de falsificações de imagens, composições são de especial interesse. Esse tipo de falsificação usa partes de duas ou mais imagens para construir uma nova realidade exibindo para o observador situações que nunca aconteceram. Entre todos os diferentes tipos de pistas investigadas para detecção de composições, as abordagens baseadas em inconsistências de iluminação são consideradas as mais promissoras uma vez que um ajuste perfeito de iluminação em uma imagem falsificada é extremamente difícil de ser alcançado. Neste contexto, esta tese, a qual é fundamentada na hipótese de que inconsistências de iluminação encontradas em uma imagem são fortes evidências de que a mesma é produto de uma composição, apresenta abordagens originais e eficazes para detecção de imagens falsificadas. O primeiro método apresentado explora o reflexo da luz nos olhos para estimar as posições da fonte de luz e do observador da cena. A segunda e a terceira abordagens apresentadas exploram um fenômeno, que ocorre com as cores, denominado metamerismo, o qual descreve o fato de que duas cores podem aparentar similaridade quando iluminadas por uma fonte de luz mas podem parecer totalmente diferentes quando iluminadas por outra fonte de luz. Por fim, nossa última abordagem baseia-se na interação com o usuário que deve inserir normais 3-D em objetos suspeitos da imagem de modo a permitir um cálculo mais preciso da posição 3-D da fonte de luz na imagem. Juntas, essas quatro abordagens trazem importantes contribuições para a comunidade forense e certamente serão uma poderosa ferramenta contra falsificações de imagens
Abstract: Once taken for granted as genuine, photographs are no longer considered as a piece of truth. With the advance of digital image processing and computer graphics techniques, it has been easier than ever to manipulate images and forge new realities within minutes. Unfortunately, most of the times, these modifications seek to deceive viewers, change opinions or even affect how people perceive reality. Therefore, it is paramount to devise and deploy efficient and effective detection techniques. From all types of image forgeries, composition images are specially interesting. This type of forgery uses parts of two or more images to construct a new reality from scenes that never happened. Among all different telltales investigated for detecting image compositions, image-illumination inconsistencies are considered the most promising since a perfect light matching in a forged image is still difficult to achieve. This thesis builds upon the hypothesis that image illumination inconsistencies are strong and powerful evidence of image composition and presents four original and effective approaches to detect image forgeries. The first method explores eye specular highlight telltales to estimate the light source and viewer positions in an image. The second and third approaches explore metamerism, when the colors of two objects may appear to match under one light source but appear completely different under another one. Finally, the last approach relies on user¿s interaction to specify 3-D normals of suspect objects in an image from which the 3-D light source position can be estimated. Together, these approaches bring to the forensic community important contributions which certainly will be a strong tool against image forgeries
Doutorado
Ciência da Computação
Doutor em Ciência da Computação
Cui, Chen. "Adaptive weighted local textural features for illumination, expression and occlusion invariant face recognition". University of Dayton / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1374782158.
Texto completoHsu, Ken. "Stochastic analysis of lateral resolution and signal-to-noise ratio in fluorescence microscopy : application to structured illumination microscopy". Thesis, University of Nottingham, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555413.
Texto completoPechacek, Christopher S. (Christopher Scott). "Space, light, and time : prospective analysis of Circadian illumination for health-based daylighting with applications to healthcare architecture". Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44282.
Texto completoIncludes bibliographical references (p. 120-129).
Light in architecture can be studied for its objective or perceptual effects. This thesis describes an objective link between human health and architectural design. Specifically, the link between daylight and human circadian rhythm (as a proxy for health) is explored. The purpose of this thesis is increase understanding about the health effects of daylighting in architecture. Little in the way of rigorous analysis exists in the emerging field of "evidence-based" design; however billions of dollars are committed to healthcare construction in the United States annually. The next generation of hospitals will certainly be guided by "evidence-based" findings, and so a better understanding of daylight's role in human physiology may influence future healthcare architecture. Therefore, the technical problem addressed here is the prospective analysis of architectural design for circadian stimulus potential based on the state of the art in photobiology. This combines lighting intensity, timing, and spectrum. Included in this thesis are specific recommendations for architectural design, which are based on scientific application of biological findings. Guidelines for circadian illumination are developed and applied. Evaluation of lighting sources (i.e. daylighting, artificial lighting) will reveal those elements of each necessary to meet circadian illumination guidelines. Recommendations for architectural designers will follow that describe how building design can maximize the application of daylighting to promote circadian organization, and thus improve the health potential of the built environment.
by Christopher S. Pechacek.
S.M.
Pilleboue, Adrien. "Analyse spatiale et spectrale des motifs d'échantillonnage pour l'intégration Monte Carlo". Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10225/document.
Texto completoSampling is a key step in rendering pipeline. It allows the integration of light arriving to a point of the scene in order to calculate its color. Monte Carlo integration is generally the most used method to approximate that integral by choosing a finite number of samples. Reducing the bias and the variance of Monte Carlo integration has become one of the most important issues in realistic rendering. The solutions found are based on smartly positioning the samples points in a way that maximizes the uniformity of the distribution while avoiding the regularities. From this point of view, the 80s were a turning point in this domain, as new stochastic methods appeared. With a better comprehension of links between Monte Carlo integration and sampling, these methods allow the reduction of noise and of variance in rendered images. In parallel, the complexity of sampling methods has considerably enhanced, enabling to have fast as well as good quality methods. However, these improvements have been done by trial and error focusing on two major points : the improvement of sampling pattern uniformity, and the suppression of regularities. Even though there exists some theories allowing to bound the error of the integration, they are usually limited, and even inapplicable in computer graphics. This thesis proposes to gather the analysis tools of sampling patterns and to connect them together. These tools can characterize spatial properties such as the distribution of distances between points, as well as spectral properties via Fourier transformation. Secondly, we have used these tools in order to give a simple expression of the bias and the variance for Monte Carlo integration ; this is done by using prerequisites compatible with image rendering. Finally, we present a theoretical toolbox allowing to determine the convergence speed of a sampling method from its spectral profile. This toolbox is used specifically to give indications about the design principles necessary for new sampling algorithms
Keresztes, Janos C., Koshel R. John, Karlien D’huys, Ketelaere Bart De, Jan Audenaert, Peter Goos y Wouter Saeys. "Augmented design and analysis of computer experiments: a novel tolerance embedded global optimization approach applied to SWIR hyperspectral illumination design". OPTICAL SOC AMER, 2016. http://hdl.handle.net/10150/622951.
Texto completoKopřiva, Antonín. "Analýza tvorby třísky pomocí digitální vysokorychlostní kamery". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229651.
Texto completoSunkavalli, Kalyan. "Models of Visual Appearance for Analyzing and Editing Images and Videos". Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10285.
Texto completoEngineering and Applied Sciences
Ковальська, Вікторія Володимирівна. "Analysis of the light pollution in the city of Kyiv". Thesis, Національний авіаційний університет, 2020. https://er.nau.edu.ua/handle/NAU/49682.
Texto completoObject of research – processes of pollution formation under the influence of artificial light sources. Aim оf work – assessment of the light pollution level and its impact on environment. Mehods of research: methods of analysis of sky by Bortle scale; comparative analysis of the obtained values of light level in the Kyiv city
У наш час штучні джерела світла є невід’ємною частиною сучасні міста. Однак проблема полягає в тому, що їх кількість значно перевищує необхідну забезпечити достатній рівень освітлення на вулицях міста. У наш час проблема світла забруднення міст стає все більш важливим, оскільки це питання погано регулюється досудовий рівень. А вплив світлового забруднення відчуває і населення міста, і біота в цілому.
Ковальська, Вікторія Володимирівна. "Analysis of the light pollution in the city of Kyiv". Thesis, Національний авіаційний університет, 2020. https://er.nau.edu.ua/handle/NAU/44801.
Texto completoObject of research – processes of pollution formation under the influence of artificial light sources. Aim оf work – assessment of the light pollution level and its impact on environment. Mehods of research: methods of analysis of sky by Bortle scale; comparative analysis of the obtained values of light level in the Kyiv city
У наш час штучні джерела світла є невід’ємною частиною сучасні міста. Однак проблема полягає в тому, що їх кількість значно перевищує необхідну забезпечити достатній рівень освітлення на вулицях міста. У наш час проблема світла забруднення міст стає все більш важливим, оскільки це питання погано регулюється досудовий рівень. А вплив світлового забруднення відчуває і населення міста, і біота в цілому.
CASINI, ANDREA EMANUELE MARIA. "Multidisciplinary modelling and simulation for assisting the space mission design process using Virtual Reality". Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2715849.
Texto completoPettersson, Johan. "Real-time Object Recognition on a GPU". Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10238.
Texto completoShape-Based matching (SBM) is a known method for 2D object recognition that is rather robust against illumination variations, noise, clutter and partial occlusion.
The objects to be recognized can be translated, rotated and scaled.
The translation of an object is determined by evaluating a similarity measure for all possible positions (similar to cross correlation).
The similarity measure is based on dot products between normalized gradient directions in edges.
Rotation and scale is determined by evaluating all possible combinations, spanning a huge search space.
A resolution pyramid is used to form a heuristic for the search that then gains real-time performance.
For SBM, a model consisting of normalized edge gradient directions, are constructed for all possible combinations of rotation and scale.
We have avoided this by using (bilinear) interpolation in the search gradient map, which greatly reduces the amount of storage required.
SBM is highly parallelizable by nature and with our suggested improvements it becomes much suited for running on a GPU.
This have been implemented and tested, and the results clearly outperform those of our reference CPU implementation (with magnitudes of hundreds).
It is also very scalable and easily benefits from future devices without effort.
An extensive evaluation material and tools for evaluating object recognition algorithms have been developed and the implementation is evaluated and compared to two commercial 2D object recognition solutions.
The results show that the method is very powerful when dealing with the distortions listed above and competes well with its opponents.
Kreuser, Carla Louise. "The meandering narrative : poetry and illustration engage in a moment of indiscipline : demonstrated in an analysis of Sara Fanelli’s illuminated poem - And all men kill the thing they love". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86503.
Texto completoENGLISH ABSTRACT: This is a study about the inner workings of an illuminated poem – about the dialogue that develops between poetry and illustration when they encounter each other on the page. However, the illuminated poem is more than just a relation between words and images, it is also a composite art in its own right. This study explores the dynamic of this particular type of imagetext by firstly claiming that the illuminated poem embodies a moment of indiscipline and secondly, by positing that illustration should contribute to this pairing by acting as a manifestation of illumination, instead of posturing as merely ‘illustrative’ or decorative. The inherent indisciplinarity of the illuminated poem as an imagetext is dissected – it is simultaneously two independent art forms and an integrated one; it can therefore be seen as both an interdisciplinary concern and a new art form. The illuminated poem as a visual art blurs the boundaries between words and images, upending the traditional, rigid boundaries of image-‐text discourse. Additionally, a meandering narrative is set in motion when poetry and illustration engage in an illuminated poem – a slower, involved, cross-‐pollinating reading that results in the activation of a reader’s imagination. The idea of Illumination is thus examined as both an orchestrated, visual choice and an active, conjuring process. Various strategies of illumination – with which illustration can open up a poem to new conceptual and narrative possibilities – are also discussed. These theories of interplay and interaction are then applied to an analysis of And all men kill the thing they love, an illuminated poem by Sara Fanelli and Oscar Wilde, revealing some of the ways in which illustration and poetry act as co-‐conspirators and collaborators when they engage in a moment of indiscipline.
AFRIKAANSE OPSOMMING: Hierdie is ‘n ondersoekende studie na die dieperliggende werking van ‘n “illuminated” gedig. Die studie fokus op die dialoog wat ontstaan wanneer ‘n gedig en illustrasies mekaar op papier ontmoet. Die “illuminated” gedig is egter soveel meer as net die saamgestelde som van woord en beeld – dit is ook ‘n verstrengelde nuwe kunswerk in eie reg. Hierdie studie verken die dinamiek van dié besondere soort beeldteks deur, eerstens, te verklaar dat “illumination” ‘n moment van ongedissiplineerdheid behels en, tweedens, deur te verwag dat die illustrasies bydra tot hierdie verhoudingsdinamika deur ‘n manifestasie van “illumination”, pleks van net ‘illustrerend’ of dekoratief, te wees. Die inherente ongedissiplineerdheid van die “open-‐ended” gedig as beeldteks word ondersoek – dit vorm tegelykertyd twee onafhanklike kunsvorms en ‘n geïntegreerde geheel; dit kan dus beskou word as beide ‘n interdissiplinêre kunswerk en ‘n nuwe kunsvorm. Die ‘mengsel’-‐gedig as visuele kunsvorm oorskry die bekende grense tussen woorde en beelde en gooi alle rigiede, streng-‐tradisionele riglyne van die beeldteks-‐geding omver. Die verhaaltrant volg kronkelpaaie wanneer digkuns en illustrasie slaags raak op papier of meedoen aan die “open-‐ended” gedig – ‘n stadiger, meer betrokke, kruisbestuiwende leestempo word afgedwing, wat sodoende die leser se verbeelding aktiveer. Die idee van “illumination” word dus ondersoek as beide ‘n georkestreerde, visuele keuse en ‘n meelewende (verwonderings)proses. Verskeie verhelderings-‐ moontlikhede – waardeur illustrasie ‘n gedig kan ontsluit om nuwe konseptuele en vertellingsmoontlikhede te ontgin – word ook bespreek. Hierdie teoretiese benadering van ‘n heen-‐en-‐weer-‐spel se wisselwerkende interaksie word dan toegepas op ‘n analise van And all men kill the thing they love, ‘n “illuminated” gedig deur Sara Fanelli en Oscar Wilde. Verskeie wyses waarop illustrasie en digkuns as samesweerders en samewerkers kan optree wanneer hulle hulself in ‘n oomblik van ongedissiplineerdheid bevind, word aangetoon.
Tomeš, Martin. "Simulace LED náhrad v reálných podmínkách". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220695.
Texto completoZhang, Yuyao. "Non-linear dimensionality reduction and sparse representation models for facial analysis". Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0019/document.
Texto completoFace analysis techniques commonly require a proper representation of images by means of dimensionality reduction leading to embedded manifolds, which aims at capturing relevant characteristics of the signals. In this thesis, we first provide a comprehensive survey on the state of the art of embedded manifold models. Then, we introduce a novel non-linear embedding method, the Kernel Similarity Principal Component Analysis (KS-PCA), into Active Appearance Models, in order to model face appearances under variable illumination. The proposed algorithm successfully outperforms the traditional linear PCA transform to capture the salient features generated by different illuminations, and reconstruct the illuminated faces with high accuracy. We also consider the problem of automatically classifying human face poses from face views with varying illumination, as well as occlusion and noise. Based on the sparse representation methods, we propose two dictionary-learning frameworks for this pose classification problem. The first framework is the Adaptive Sparse Representation pose Classification (ASRC). It trains the dictionary via a linear model called Incremental Principal Component Analysis (Incremental PCA), tending to decrease the intra-class redundancy which may affect the classification performance, while keeping the extra-class redundancy which is critical for sparse representation. The other proposed work is the Dictionary-Learning Sparse Representation model (DLSR) that learns the dictionary with the aim of coinciding with the classification criterion. This training goal is achieved by the K-SVD algorithm. In a series of experiments, we show the performance of the two dictionary-learning methods which are respectively based on a linear transform and a sparse representation model. Besides, we propose a novel Dictionary Learning framework for Illumination Normalization (DL-IN). DL-IN based on sparse representation in terms of coupled dictionaries. The dictionary pairs are jointly optimized from normally illuminated and irregularly illuminated face image pairs. We further utilize a Gaussian Mixture Model (GMM) to enhance the framework's capability of modeling data under complex distribution. The GMM adapt each model to a part of the samples and then fuse them together. Experimental results demonstrate the effectiveness of the sparsity as a prior for patch-based illumination normalization for face images
Khan, Zulfiqar A. "EMI/EMC analysis of electronic systems subject to near zone illuminations". Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196207323.
Texto completoPonchia, Chiara. "Frammenti dell'Aldilà. Immagini nella Divina Commedia nell'Italia settentrionale del Trecento". Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3423513.
Texto completoIl mio lavoro ha come oggetto la genesi e lo sviluppo dell’illustrazione miniata della Divina Commedia nell’Italia nord-orientale nel XIV secolo. La tesi muove dall’individuazione di un corpus di manoscritti significativi per numero di immagini e tipologie illustrative impiegate. Ai manoscritti principali è dedicato un capitolo di approfondimento finalizzato soprattutto a rilevare le principali problematiche storico-artistiche ad essi correlate. Particolare attenzione è dedicata all’Egerton 943, per il quale si propone una nuova datazione. Il lavoro prosegue con un’attenta analisi delle soluzioni adottate dai miniatori della Divina Commedia per illustrare un testo nuovo e pertanto privo di una tradizione iconografica consolidata. Ampio spazio è dato allo studio delle fonti, visive e in alcuni casi testuali, cui si rivolsero i miniatori in cerca di ispirazione, partendo da alcuni affondi analitici sulle iconografie adottate per raffigurare i personaggi principali, quali ad esempio Caronte e Minosse, per poi passare allo studio dei modelli visivi scelti per ricreare le ambientazioni di inferno, purgatorio e paradiso. Allo studio della figurazione si aggiunge poi l’analisi delle principali forme di rapporto testo-immagine nei codici padani della Divina Commedia. Anche in questo caso vengono prese in esame le possibili fonti, attraverso un’approfondita ricognizione delle principali tipologie di racconto per immagine riscontrabili nell’Italia nord-orientale tra la fine del Duecento e l’inizio del secolo successivo. In particolare, si è rivelato proficuo lo studio dei codici cavallereschi, che paiono essere l’ambito privilegiato di elaborazione dei principali sistemi impaginativi che saranno poi impiegati nei più antichi testimoni settentrionali del poema.
Bodnarova, Adriana. "Texture analysis for automatic visual inspection and flaw detection in textiles". Thesis, Queensland University of Technology, 2000.
Buscar texto completoLeoputra, Wilson Suryajaya. "Video foreground extraction for mobile camera platforms". Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/1384.
Texto completoAlderman, Gwendolyn. "From policy borrowing to implementation : an illuminative evaluation of learning and teaching in higher education in Australia (2002 to 2008)". Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/75865/1/Gwendolyn_Alderman_Thesis.pdf.
Texto completoLösche, Frank. "Investigating the moment when solutions emerge in problem solving". Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/12838.
Texto completoHubel, Philipp [Verfasser] y Matthias [Akademischer Betreuer] Mann. "Illuminating novel aspects in virus-host interactions by tailored quantitative proteomics analyses / Philipp Hubel ; Betreuer: Matthias Mann". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2019. http://d-nb.info/121985221X/34.
Texto completoThorpe, Robert Nicholas. "Evaluating an English department: the use of illuminative evaluation procedures in descriptive and diagnostic analysis of English teaching programmes in high schools". Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1003404.
Texto completoReid, Rhiannon Sara. "An activity theory analysis of how management of a private higher education institution interpret and engage with re-accreditation". Master's thesis, Faculty of Humanities, 2021. http://hdl.handle.net/11427/33905.
Texto completoNichterwitz, Melanie [Verfasser] y Bernd [Akademischer Betreuer] Rech. "Charge carrier transport in Cu(In,Ga)Se2 thin-film solar-cells studied by electron beam induced current and temperature and illumination dependent current voltage analyses / Melanie Nichterwitz. Betreuer: Bernd Rech". Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2012. http://d-nb.info/1023762145/34.
Texto completo"Image-based illumination analysis and applications". Thesis, 2010. http://library.cuhk.edu.hk/record=b6075248.
Texto completoIllumination is a very common phenomenon. All the photographs that we casually take with cameras exhibit such phenomenon. Computer graphicists usually simulate the illumination cast on objects based on physical models. While directly rendering such effects has been intensively studied in the field of computer graphics, the inverse estimation of illumination contribution to each pixel in the digital photographs, which we call image-based illumination estimation, still remains a challenging problem. The lack of the underlying geometry as well as the light source and material properties usually makes such inverse estimation ill-posed and a very difficult problem to solve.
In this thesis, we target on such image-based illumination estimation problem. We will review the current state-of-the-art illumination estimation algorithms for solving intrinsic images, and demonstrate their benefits and drawbacks. While this is a fundamental research problem in the field of computer vision, we show that by decomposing the image into its intrinsic components, the reflectance and illumination, many graphical applications can potentially be explored and benefited. In the meantime, we will also introduce a new and novel algorithm to efficiently estimate the intrinsic components based on the statistics of the textured regions. The same algorithm can also be directly applied to non-textured regions in an image.
Texture synthesis is a very fundamental problem in computer graphics. Current texture synthesis method is difficult to automatically take into account the illumination and deformation during the synthesis. By exploring the statistics of the texture, we propose a very efficient algorithm to estimate both the illumination and deformation fields on textures. The color of the illuminant is also taken into account so that the recovered reflectance has consistent color. By decomposing the illumination and deformation fields, we show that many texture-based applications, such as the preparation of texture exemplars from real photographs, the natural replacement of textured regions, the relighting of objects, as well as the manipulation of geometries in natural images can be well achieved, with the success of texture synthesis guided by illumination and deformation.
Traditional example-based colorization of natural images usually suffers from illumination inconsistency. The color transfer from areas such as highlights and shadows may severely harm the colorization result. We propose to consider the illumination problem in colorization and perform colorization in an illumination-free domain. The decomposition of the intrinsic components from multiple example images, as well as the recombination and utilization of these intrinsic components in colorization, form the foundation of the proposed technique. Consistent colorization results are obtained even though the example images are from different lighting conditions and viewing directions.
Liu, Xiaopei.
Adviser: Wong Tien Tsin.
Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: .
Thesis (Ph.D.)--Chinese University of Hong Kong, 2010.
Includes bibliographical references (leaves 76-83).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.
Dai, Liang-Kuang y 戴良光. "Scene Change Detection based on Illumination Analysis". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/81025030771805941378.
Texto completo淡江大學
資訊工程學系碩士班
96
In recent years, due to the rapid progress of computer science, internet is flooded with multimedia data, especially video, which has the most variety of information. For video on the organization and indexing, the video shot boundary detection is essential work. In general, the shot is usually regarded as the basic unit of the video, video shot boundary detection is to provide us to do video summary, retrieval and browsing. In this system, we use illumination change data to detect shot boundary based on HSV color space and to check shot change type. In the experiment result, the most common shot change types which are cut, fade and dissolve has high degree of accuracy of detection.
TSENG, CHI-YUAN y 曾啟淵. "The Illumination Analysis of Indoor Table Lamp". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/nf8chv.
Texto completo國立屏東大學
應用物理系碩士班
107
Table lamps are important for reading in which the illumination distribution and glare would influence the vision of the eyes. It is important to understand the fact that would influence the degree of glare. In this thesis, a table lamp located on a table inside a room was simulated, and its illumination distributions were discussed. In order to quantized the degree of glare, the unified glare rating (UGR) which was defined by CIE was utilized in this thesis. Besides, the table was divided into four regions for convenient understanding the distribution of glare. The table lamp could be consisted of fluorescent lamps with V-shaped reflector or LEDs. The simulated results of these two kind of table lamps showed that the illumination distributions and UGR would not affected by the types of lamps, but the additional diffuser of LED table lamp would efficiently degrade the degree of glare. By the way, the background illumination was also an important factor which would influence the degree of glare, no matter the indoor lamps on the floor or the natural illuminations. Besides, the orientations of table lamps, table and indoor lamps would also.
Chen, C. W. y 陳智偉. "Calibration and Error Analysis for Stroboscopic Illumination Ellipsometry". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/88051764939774963581.
Texto completo國立交通大學
光電工程系所
95
Stroboscopic illumination ellipsometry is a fast imaging technique which operates by synchronizing the ultra stable short pulse to freeze the variation of Photoelastic Modulator (PEM) signal. Four specific polarization states are used to deduce the ellipsometric parameters (Ψ,Δ) . We postulate the main deviation of ellipsometric parameters in stroboscopic illumination ellipsometry is caused by the deviation of initial temporal phase and modulation amplitude. In this paper, we will derive a correction technique to optimize ellipsometric parameters. Finally, an optical thin film of known thickness was measured to demonstrate the reliability of this correction technique. We can eliminate errors caused by the miss positioned initial time and modulation amplitude deviation. This post flight measurement technique can eliminate all the system errors and achieve dΨ~0.03° and dΔ~0.41° in 20 microsecond.
Chu, Fu-Wei y 初福威. "Application and Analysis of Indoor Low Illumination Photometer". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/8s4rq2.
Texto completo國立虎尾科技大學
光電與材料科技研究所
100
As for the human eyes, when the illumination intensity is too low, the human eyes will easily lead to eye fatigue. On the contrary, if the illumination intensity is too high due to intense light, excessive waste of electricity will undoubtedly occur. In this thesis, the Holtek microcontroller HT46R64, Solteamopto photoelectric light sensor JSA-1116, and JSA-3111B are used to convert the strength of the light intensity into voltage; analog-to-digital converter (ADC) is employed to transform the analog signals into digital ones. Finally, the ADC results are displayed via the help of microcontroller. For various environments, users need to have the appropriate illumination condition to match the actual requirements for book-reading, requiring a range of lux from 300 to 500. Our motivation is to devise a compact photometer for indoor illumination, where the detection range is between 0 and 1000 lux. Due to the cost and wide measurement ranges of these photometer products available in the market, this thesis is intended to design a low cost, portable photometer; real-time measurement task can always be conducted under any desk lamp illumination scenario, and the estimated cost is around NT$399.
"Compressing the illumination-adjustable images with principal component analysis". 2003. http://library.cuhk.edu.hk/record=b5891490.
Texto completoThesis (M.Phil.)--Chinese University of Hong Kong, 2003.
Includes bibliographical references (leaves 90-95).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Background --- p.1
Chapter 1.2 --- Existing Approaches --- p.2
Chapter 1.3 --- Our Approach --- p.3
Chapter 1.4 --- Structure of the Thesis --- p.4
Chapter 2 --- Related Work --- p.5
Chapter 2.1 --- Compression for Navigation --- p.5
Chapter 2.1.1 --- Light Field/Lumigraph --- p.5
Chapter 2.1.2 --- Surface Light Field --- p.6
Chapter 2.1.3 --- Concentric Mosaics --- p.6
Chapter 2.1.4 --- On the Compression --- p.7
Chapter 2.2 --- Compression for Relighting --- p.7
Chapter 2.2.1 --- Previous Approaches --- p.7
Chapter 2.2.2 --- Our Approach --- p.8
Chapter 3 --- Image-Based Relighting --- p.9
Chapter 3.1 --- Plenoptic Illumination Function --- p.9
Chapter 3.2 --- Sampling and Relighting --- p.11
Chapter 3.3 --- Overview --- p.13
Chapter 3.3.1 --- Codec Overview --- p.13
Chapter 3.3.2 --- Image Acquisition --- p.15
Chapter 3.3.3 --- Experiment Data Sets --- p.16
Chapter 4 --- Data Preparation --- p.18
Chapter 4.1 --- Block Division --- p.18
Chapter 4.2 --- Color Model --- p.23
Chapter 4.3 --- Mean Extraction --- p.24
Chapter 5 --- Principal Component Analysis --- p.29
Chapter 5.1 --- Overview --- p.29
Chapter 5.2 --- Singular Value Decomposition --- p.30
Chapter 5.3 --- Dimensionality Reduction --- p.34
Chapter 5.4 --- Evaluation --- p.37
Chapter 6 --- Eigenimage Coding --- p.39
Chapter 6.1 --- Transform Coding --- p.39
Chapter 6.1.1 --- Discrete Cosine Transform --- p.40
Chapter 6.1.2 --- Discrete Wavelet Transform --- p.47
Chapter 6.2 --- Evaluation --- p.49
Chapter 6.2.1 --- Statistical Evaluation --- p.49
Chapter 6.2.2 --- Visual Evaluation --- p.52
Chapter 7 --- Relighting Coefficient Coding --- p.57
Chapter 7.1 --- Quantization and Bit Allocation --- p.57
Chapter 7.2 --- Evaluation --- p.62
Chapter 7.2.1 --- Statistical Evaluation --- p.62
Chapter 7.2.2 --- Visual Evaluation --- p.62
Chapter 8 --- Relighting --- p.65
Chapter 8.1 --- Overview --- p.66
Chapter 8.2 --- First-Phase Decoding --- p.66
Chapter 8.3 --- Second-Phase Decoding --- p.68
Chapter 8.3.1 --- Software Relighting --- p.68
Chapter 8.3.2 --- Hardware-Assisted Relighting --- p.71
Chapter 9 --- Overall Evaluation --- p.81
Chapter 9.1 --- Compression of IAIs --- p.81
Chapter 9.1.1 --- Statistical Evaluation --- p.81
Chapter 9.1.2 --- Visual Evaluation --- p.86
Chapter 9.2 --- Hardware-Assisted Relighting --- p.86
Chapter 10 --- Conclusion --- p.89
Bibliography --- p.90
Chang, Ya-hui y 張雅惠. "Comparison and analysis of global natural lighting illumination system". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/07865255196404984078.
Texto completo國立臺灣科技大學
電子工程系
101
In recent years, green energy has undergone a lot of development and has been the subject of many ap-plication. Many research studies have focused on illumination with sunlight as a means of saving energy and creating healthy lighting [1]. It has been the most important issue how to save energy and the development of new renewable energy sources in growing shortage of energy[2-7]. The electricity consumption for lighting accounts for about 10% of all electricity consumption to 20% every year [8].Now developed many kinds of natural light system methods. Natural light systems have collecting, transmitting, and lighting elements. This system will provide a great number of benefits for the people who use it[1]. By this system, we can bring daylight into interior for lighting use. This paper is to discuss different construction of natural light system and introduct a variety of environments which need to the natural light system that provides natural light guiding system constructed index.
Huang, Shou-Tsung y 黃紹宗. "Surface Design and Illumination Analysis of Reflector for Surgical Operating". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/83239492270312982491.
Texto completoChen, Chi-Kang y 陳紀鋼. "Design and Analysis of Modern LED Lens for Collimating Illumination". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/24256849791166878138.
Texto completo淡江大學
機械與機電工程學系碩士班
102
This thesis explores the secondary optical lens design and analysis for generating collimating illumination in LED source. In the first phase of this study, a comprehensive paper review provides valuable and technical information. Then three types of lens are selected based on the most recent development with highly optical performances. The lens''s curve is constructed by adopting free-form method in which a series of computing points can be obtained for generating graphical solid model. The optical analysis can be executed by the Light Tools. This thesis proposed four requirements to achieve collimating illumination in modern LED lens, as follows. 1. The process of constructing lens curve is simple and correct. 2. The output optical efficiency must be greater 80% within beam angle. 3. Easy manufacture for reducing the cost. 4. For the volume restriction in practical consideration, the diameter and the axial length of lens may be constrained. According to those four requirements several design improvement in published works are carried out, and discussed. At the final stage, this thesis develops a innovative lens that can achieve 99.28% optical efficiency. Also, when axial length and diameter are predetermined, another development is introduced for comparison and discuss. Both of the new lenses agree four critical requirements in of modern LED lens for collimating illumination.
LI, CHIH-HSUAN y 李治軒. "Visibility Dehazing based on Channel-Weighted Analysis and Illumination Enhancement". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/36250754204916969607.
Texto completo逢甲大學
資訊工程學系
105
The air pollution and foggy weather often result in serious distortion while taking photos or recognizing patterns. He et al. have introduced the dark channel prior to solve this dehazing problem. Unfortunately, it cannot function well once the color difference of target image is large. More precisely, the dehazed result looks unnatural. Thus, we aim to develop a brand-new visibility dehazing technique based on the channel-weighted analysis and illumination tuning. The channel-weighted analysis is adopted to eliminate the unnatural effect, while the illumination tuning is applied to refine the details. Simulation results have demonstrated that the new method can guarantee the readability of a hazed image after removing noise, including the foggy photo and sandstorm one.
Wu, Chien-chun y 吳健君. "The analysis of different LED chip size for spotlight illumination". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/27600292182274598071.
Texto completo國立中央大學
光電科學與工程學系
101
In this thesis, we focused on five similar packages of high-power LEDs and analyzed the effective exitance of each LEDs, which were driven at the same current density. Effective exitance was depended on efficacy and emitting area. When the light passed through lens encapsulation, the emitting area would be changed. Finally, we designed a miniaturization bike lamp, the light source of which was the highest effective exitance LED, for meeting K-mark regulation. The prototype was fabricated by CNC machining and the measured light pattern was similar to design one.