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Extraction de paramètres bio-geo-physiques de surfaces 3D reconstruites par multi-stéréo-restitution d'images prises sans contraintesPetitpas, Benoit 15 December 2011 (has links) (PDF)
Extraire des mesures sur des surfaces est un problème dans de nombreux domaines de recherche. L'archaïsme de certains systèmes ou la cherté d'appareils perfectionnés empêchent l'extraction rapide et robuste de ces paramètres. Pourtant, ils sont essentiels dans de nombreux domaines, comme les paramètres de rugosité qui interviennent dans de nombreux phénomènes physiques ou les valeurs dendrométriques pour l'étude de la bio-diversité. En parallèle, l'utilisation et la production de contenus 3D se développent considérablement ces dernières années dans des domaines très divers. Le but de cette thèse est donc d'utiliser toutes ces innovations dans le domaine de la reconstruction 3D et de les appliquer à la mesure de paramètres de surfaces. Pour cela, il est nécessaire de créer une chaîne complète de reconstruction 3D, n'utilisant que des images prises sans contrainte dans le but d'être accessible au plus grand nombre. Dans cette chaîne nous utilisons des algorithmes de stéréo-vision robustes produisant, pour chaque couple d'images, un nuage de points. Après le passage de ces nuages dans un référentiel commun, une étape de filtrage des points 3D et de suppression des redondances est nécessaire. Une étape de lissage permet d'obtenir le nuage final. Pour justifier des bons résultats obtenus, une étape de validation nous a permis de vérifier et d'étudier la robustesse de la chaîne de traitements développée. Enfin, les paramètres de rugosités et dendrométriques seront extraits. Nous étudierons dans ces deux cas, comment extraire ces informations et leurs utilisations
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NURBS paviršiai mobiliuosiuose įrenginiuose / NURBS surfaces on mobile devicesMasiulionytė, Vaida 02 July 2014 (has links)
Darbe yra apžvelgiamos NURBS paviršių atvaizdavimo realizavimo problemos mobiliesiems įrenginiams. Pagrindinis darbo tikslas yra įsitikinti tokios realizacijos galimumu, bei surasti kiek įmanoma efektyvesnį būdą, išsprendžiantį mobiliųjų platformų realizacijų problemas. Dar vienas tikslas, sukurti prototipinį sprendimą, padengiantį NURBS standartą. Analizei pasirinkta M3G mobiliosios grafikos standartas, kuris šiuo metu yra labiausiai paplitęs. Realizacijų palyginimui buvo pasirinkti du algoritmai: Oslo ir tiesioginis. Atlikus veikimo analizę nustatyta, jog tiesioginis algoritmas yra efektyvesnis, kurio pagrindu buvo išbaigtas NURBS standartas, realizuojant Trimmed NURBS modelius. / In the thesis it is analyzed the problems related with NURBS rendering implementation for mobile devices. The main goal of the thesis is to make find out if such implementation is possible at all and to find most effective way to implement it. One more goal is to create a prototype implementation for NURBS standard including Trimmed NURBS. M3G mobile graphics platform was chosen for analysis, which is mostly adopted across the vendors nowadays. There was chosen two rendering algorithms for analysis purposes: Oslo and directional. During analysis it was discovered, that Directional algorithm is more effective than Oslo, and it was adapted to prototype solution – Trimmed NURBS.
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3D-portal : Kommunikation i 3DBergman, Jens, Wallin, Fredrik January 2014 (has links)
I dagens samhälle används internet för kommunikation mellan människor runtom i världen. Det första videosamtalet gjordes runt år 1940 och det är dags fören utveckling, där 3D är något som skulle kunna göra videomöten mer verkliga.För att möjliggöra detta så konstruerades ett system som skulle kunna ta in datafrån olika time-of-flight- och färgkameror och en ljudenhet. Denna data ska sedankomprimeras och sändas över internet för att kunna spelas upp på någonannans 3D-skärm. För att samtalet inte ska kännas fördröjt måste samtliga delartillsammans ske inom realtid. De utvecklingsmetoder som har använts är parprogrammeringoch en variant utav testdriven utveckling. Systemet har utvärderatsutifrån tidmätningar, bildkvalitet och datastorlek för att hitta en bra balansmellan tid och kvalitet. Systemet konstruerades med fem delar: insamling avbilder och ljud, bilduppskalning, komprimering och avkomprimering, internetöverföringsamt rendering. Resultatet visade att de delar som berörs av datastorlekoch bildkvalitet kunde uppnå en bra balans mellan tid och kvalitet. Dockkunde inte alla mål uppnås då vissa delar tog upp mer tid än realtidsmålet samtatt alla delar inte han konstrueras. Eftersom systemet byggdes upp modulärt såkan de delar som inte uppnådde målen förbättras eller bytas ut. Utifrån resultatetkunde sedan lösningsförslag ges för att förbättra resultaten för en eventuell vidareutveckling. / In todays society internet is used for communication between each other aroundthe world. The first video call was made around the year 1940 and it is time fora development, where 3D is something that can make video calls more real. Tomake this possible a system was constructed that would be able to get data fromdifferent time-of-flight cameras and color cameras and audio devices. That datashould later on be compressed and transmitted over internet to be able to play iton someone else’s 3D-display. To prevent the feeling of delay in the call, allparts together must happen in real time. The development methods that havebeen used is pair programming and a variation of test-driven development. Thesystem has been evaluated by time messurements, image quality and data sizeto find a good balance between time and quality. The system was constructedby five parts: capturing of images and audio, image upscaling, compression anddecompression, network streaming and also rendering. The result showed thatthe parts affected by data size and image quality could achieve a good balancebetween time and quality. However, all goals could not be achieved becausesome parts where too slow for the real time goal to be achieved and also someparts could not be constructed in time. Since the system was built up modularlythe parts that did not achieve the goals can be improved or replaced. Based onthe results, solution proposals was made to improve the results for a possiblefurther development.
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2D to 3D conversion with direct geometrical search and approximation spacesBorkowski, Maciej 14 September 2007 (has links)
This dissertation describes the design and implementation of a system that has been designed to extract 3D information from pairs of 2D images. System input consists of two images taken by an ordinary digital camera. System output is a full 3D model extracted from 2D images. There are no assumptions about the positions of the cameras during the time when the images are being taken, but the scene must not undergo any modifications.
The process of extracting 3D information from 2D images consists of three basic steps. First, point matching is performed. The main contribution of this step is the introduction of an approach to matching image segments in the context of an approximation space. The second step copes with the problem of estimating external camera parameters. The proposed solution to this problem uses 3D geometry rather than the fundamental matrix widely used in 2D to 3D conversion. In the proposed approach (DirectGS), the distances between reprojected rays for all image points are minimised. The contribution of the approach considered in this step is a definition of an optimal search space for solving the 2D to 3D conversion problem and introduction of an efficient algorithm that minimises reprojection error. In the third step, the problem of dense matching is considered. The contribution of this step is the introduction of a proposed approach to dense matching of 3D object structures that utilises the presence of points on lines in 3D space.
The theory and experiments developed for this dissertation demonstrate the usefulness of the proposed system in the process of digitizing 3D information. The main advantage of the proposed approach is its low cost, simplicity in use for an untrained user and the high precision of reconstructed objects.
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Applicability of three dimensional surface scanning to age-at-death estimations based on the human pubic symphysisGray, Adam 24 August 2011 (has links)
The application of 3D laser scanning to the analysis of human skeletal remains provides the opportunity for new methodological approaches, including for the assessment of age at death. The focus of this new perspective revolves around the question of whether morphological development of skeletal features can be captured with quantitative measurements taken from 3D scanned representations of physical specimens, with the aims of adding an increased level of accuracy and precision over currently employed age estimations methods that focus on visual, and often subjective, assessments based comparisons with plaster casts and written descriptions. The current research was conducted to determine if specific morphological features of the pubic symphysis could be isolated and quantified on 3D models, and whether these measurements captured the general age related trends of symphyseal development. Using CAD software, each symphyseal face was divided into half and quadrant specific sections in an attempt to better capture the development of symphyseal morphology. A sample of left male pubic symphyses (n = 40) scanned from a well-documented collection of known-age individuals (Coimbra Identified Skeletal Collection) was selected for this study. Seven symphyseal features were identified from the Suchey-Brooks method unisex age phase descriptions. Eight measurements were generated to quantify these features. The data for each feature was subjected to linear regression analyses to test for statistical correspondence to known chronological age at death. Rim completeness, billowing height and area, and depth of symphyseal face depression demonstrated the strongest relationships with chronological age, while curvature of the ventral rampart and the angle of the dorsal aspect, showed significant but weak relationships with known age. Degree of dorsal lipping and dorsal rampart curvature showed no relationship with age. The results of the study suggest that quantitative assessments of morphological changes at the pubic symphysis are possible and therefore can potentially add further insights into age at death estimations based on the pubic symphysis, as measurements taken within CAD software are far more precise than traditional measuring implements. This study illustrates the potential for 3D imaging to improve the methods of osteological analyses applied particularly in the fields of bioarchaeology and forensic anthropology. / Graduate
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Activity-Centric Prioritized Streaming of Games to Mobile DevicesRahimi Koopayi, Hesam Aldin 22 December 2011 (has links)
As mobile devices still have limited battery life, processing power, memory, and display size, they cannot yet execute gaming applications with the same fidelity and quality as their PC counterparts. In response, researchers have recently performed research with the goal of the real-time delivery of game content specifically to fit within mobile devices’ limitations. In this thesis, we present a novel approach to tackling the streaming of objects to mobile devices. Our goal is to reduce the number of objects subject to streaming from the server to the target devices, while not violating the user-defined limitations through an efficient, context-aware 3D object selection and prioritization scheme. We take advantage of the game context to stream only the most relevant objects. Our evaluations have shown that this technique not only leads to better performance in general, but also increases the gameplay experience by helping the player to achieve a higher score.
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Creation of Chimera Through the Usage of an Inspirational SystemParish, Brandi Nicole 03 October 2013 (has links)
My thesis involves studying the nature of chimera through history and how certain aspects of chimeras represent specific features of dualities in human nature. The research was reflected in a series of sketches, where one sketch was finalized into a fully realized 3D model. To aid in this goal, I created a system that will randomly generate chimera based on different characteristics. This system was created using Max 5, and was programmed to place images with alphas on top of each other to create unique chimeras. The variables within this system are derived from the research on chimeras depicted in art and mythology throughout history, and will be used as an inspirational tool to help generate unique combinations of chimeras that may not otherwise have been imagined.
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Adaptable Three Dimensional System for Building Inspection ManagementAbou Shaar, Belal January 2012 (has links)
Sustaining the safety and operability of civil infrastructure assets, including buildings, is a complex undertaking that requires a perpetual cycle involving inspection, and further decisions for renewal fund allocation. However, inspection, which is the basis for all subsequent decisions, is a complex task to manage, particularly when a large number of assets are involved. The current lack of a structured process with visual referencing as well as the high subjectivity and inflexibility to changing inspection requirements make current inspections very costly and time consuming.
This research improves the building inspection process by introducing a 3D system for inspection management that has four unique features: (1) a structured assessment approach that considers multiple organizations, buildings and inspectors, using a GIS interface; (2) a 3D visual referencing method for marking problem areas during inspections to facilitate all on-site inspections, thus reducing time and cost; (3) a visual guidance module to reduce inspection subjectivity; and (4) a flexible module for designing different assessment types. The proposed inspection management system creates 3D building plans from 2D Computer-Aided Drawing (CAD) to provide location referencing that enhances inspection effectiveness. The visual guidance system allows inspectors with various experience levels to perform consistent inspections and requires less training, thus reducing costs. Flexible inspection generation also allows a variety of inspection types, such as condition and level of service, to be readily incorporated.
A computerized prototype system has been developed using the Windows Presentation Foundation’s XAML markup language with underlying C# programming on a tablet computer for experimentation. The thesis provides a detailed description of system development and reports the benefits of the system on a sample inspection. Accordingly, the system has proven most useful for large organizations that own a large number of building assets that require frequent inspections.
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Ansatz zur Interaktion mit dreidimensional visualisierten SoftwaremodellenKovacs, Pascal 15 August 2011 (has links) (PDF)
Softwaresysteme sind komplexe immaterielle Systeme mit einer Vielzahl von Bestandteilen und Beziehungen. Um den Aufbau, die Funktionsweise und die Entwicklung von Softwaresystemen besser zu verstehen, eignen sich Softwarevisualisierungen, welche die abstrakte Datengrundlage in eine visuelle Repräsentation übertragen. Auf Grund der Masse und der Komplexität der in der Visualisierung enthaltenen Informationen, kommt es schnell zur Unübersichtlichkeit, was sich negativ auf den Prozess des Verstehens auswirkt. Zur Beherrschung der Komplexität muss der Betrachter daher die Gesamtheit zuerst in mehrere Perspektiven unterteilen, um diese anschließend gezielt nach verschiedenen Aspekten untersuchen zu können.
Die dafür benötigten Interaktionsmöglichkeiten sind Gegenstand der Untersuchungen in dieser Arbeit, wobei im Wesentlichen Visualisierungen der Struktur von Software als Ausgangspunkt genutzt werden. Insbesondere wird der Frage nachgegangen, wie die Interaktion gestaltet werden kann, damit der Benutzer ein möglichst umfassendes Verständnis der Struktur erlangt.
Zur Umsetzung der theoretischen Erkenntnisse wird ein Prototyp vorgestellt, der automatisiert aus den Strukturinformationen eines Ecore-Modells eine interaktive dreidimensionale Softwarevisualisierung der Struktur im freien standardisierten Format Extensible 3D generiert. Der Prozess der Visualisierung wird dabei durch Werkzeuge des openArchitectureWare-Frameworks realisiert. Zur Integration in den Entwicklungsprozess ist der Prototyp in ein Plugin für Eclipse eingebettet.
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Development of 3D-EBSD and its application to the study of various deformation and annealing phenomenaMateescu, Nora-Maria, Materials Science & Engineering, Faculty of Science, UNSW January 2008 (has links)
The ability to generate three dimensional (3D) microstructures in solids is of great importance in understanding their true nature, as it eliminates speculation about the spatial distribution of features associated with conventional two dimensional (2D) imaging techniques. There are several recently-developed 3D techniques for determining the spatial distribution of microstructural features, each with a given resolution. There is considerable interest in the development of a specific serial sectioning methodology, termed 3D electron backscatter diffraction (3D-EBSD), which combines a focused ion beam (FIB) with EBSD interfaced to a field emission gun scanning electron microscope. Here, FIB is used as a serial sectioning device for cutting parallel slices of single- and multi-phase materials with a site-specific accuracy of up to 50 nm. Each consecutive slice is mapped by EBSD and the complete dataset combined using advanced computer algorithms to generate a volume of a material whereby the true crystallographic features can be analyzed at submicron resolution. The aims of the thesis was to develop 3D-EBSD into a powerful materials analysis tool and use it to resolve several issues concerning the nature of the deformed state and the nucleation and the growth behaviour of recrystallizing grains. The study commenced with an investigation into the effect of material type (restricted to face centred cubic AI, Cu and Au metallic crystals), FIB milling conditions and EBSD software variables on the quality of EBSD patterns generated on ion-milled surfaces of these materials. The effect of material type on EBSD pattern quality following FIB milling was found to be significant with relatively poor quality EBSD patterns obtained for metals of low atomic number. It was demonstrated, particularly for the high atomic number metals, that moderate FIB milling currents (~1-5nA) generated good quality EBSD maps from a given ion-milled surface. This preliminary work was necessary for balancing the time required for serial sectioning during 3D-EBSD and the generation of sufficient quality EBSD maps from each ion-milled surface. The outcomes of this investigation were applied to two major 3D-EBSD investigations on the microstructural and crystallographic characteristics of: (i) deformation features generated in a cold rolled interstitial free (IF) steel, with particular emphasis on the formation of microbands; and (ii) recrystallization of a cold rolled nickel alloy containing coarse (>1 ??m) silica particles, with particular attention given to the generation of particle deformation zones and their influence on nucleation and growth of recrystallizing grains including particle stimulated nucleation (PSN), twin formation during PSN and the growth behaviour of various types of grain boundary into the deformation microstructure. The foregoing 3D-EBSD studies were significant as they revealed various microstructural and crystallographic features not usually clearly evident in conventional 2D micrographs obtained by either EBSD or optical metallography. For example, the technique demonstrated that microbands in cold rolled IF steel consist of irregular curved surfaces that reconcile findings that microbands straight and aligned parallel to slip planes when viewed in normal direction-rolling direction sections but are wavy in transverse direction-rolling direction sections. Three slip planes were found within the angular range of the curved surface of the microband, which indicates that multiple slip planes are operative during deformation. The work also showed the influence of particle diameter on the misorientations generated within particle deformation zones and clearly showed that particle stimulated nucleation (PSN) occurred at particles greater than 1.5-2 ??m. It was observed that PSN in the nickel sample also generates contiguous grains separated by both coherent and incoherent twin boundaries and, on further growth of these grains into the matrix, the coherent boundary dominates and remains parallel to the primary growth direction of the grains.
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