Tesi sul tema "3d photography"
Segui questo link per vedere altri tipi di pubblicazioni sul tema: 3d photography.
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "3d photography".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Scott-Murray, Amy. "Applications of 3D computational photography to marine science". Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=233937.
Testo completoAbstract (sommario):
This thesis represents the first dedicated study of the application of computational photography in marine science. It deals chiefly with the acquisition and use of photogrammetrically derived 3D organism models. The use of 3D models as 'virtual specimens' means that they may be securely archived and are accessible by anyone in any part of the world. Interactive 3D objects enhance learning by engaging the viewer in a participatory manner, and can help to clarify features that are unclear in photographs or diagrams. Measurements may be taken from these models for morphometric work, either manually or in an automated process. Digital 3D models permit the collection of novel metrics such as volume and surface area, which are very difficult to take by traditional means. These, and other metrics taken from 3D models, are a key step towards automating the species identification process. Where an organism changes over time, photogrammetry offers the ability to mathematically compare its shape before and after change. Sponge plasticity in response to stress and injury is quantified and visualised here for the first time. An array of networked underwater cameras was constructed for simultaneous capture of image sets. The philosophy of adapting simple, cheap consumer hardware is continued for the imaging and quantification of marine particulates. A restricted light field imaging system is described, together with techniques for image processing and data extraction. The techniques described are shown to be as effective as traditional instruments and methods for particulate measurement. The array cameras used a novel epoxy encapsulation technique which offers significant weight and cost advantages when compared to traditional metal pressure housings. It is also described here applied to standalone autonomous marine cameras. A fully synchronised autonomous in situ photogrammetry array is now possible. This will permit the non-invasive archiving and examination of organisms that may be damaged by recovery to the surface.
2
Ferguson, Paul. "Development of a 3D audio panning and realtime visualisation toolset using emerging technologies". Thesis, Edinburgh Napier University, 2010. http://researchrepository.napier.ac.uk/Output/6698.
Testo completoAbstract (sommario):
This thesis documents a body of research that links the field of electro-acoustic diffusion and spatialisation with practice in the music and film post-production industries. Three research questions are posed: "How can the physical user-interfaces used for panning by the music and film post-production industries offer creative alternatives to the fader-based hardware approach commonly used for electro-acoustic performance?" "How can a Digital Audio Workstation (DAW) be used as an alternative to dedicated panning hardware? "How can emerging programming technologies offer creative alternatives to the MAX/MSP or hardware-based tools commonly used for sound spatialisation?" This practice-based PhD addresses these questions by designing, developing and testing a set of hardware and software tools, the Requirement Specification for this `Toolset' results from literature review and critical analysis of current systems to determine potential research gaps. This analysis is followed by the selection of a suitable methodology for development and testing that allows the research questions to be explored effectively and results in the following Toolset: OctoPanner: Amulti-featured eight-channel 3D touchscreen panner application for Apple's Mac OS X controlling a DAW hosted customisable VST 3D panning plug-in with C++ source code. ShapePanner: A synchronisable shape-based sequencer application for Mac OS X inspired by Experimentalstudio's Halaphon. The user is ab{e to describe the movement of sounds in a 3D space using shape primitives such as lines and circles and thus extend the capabilities of the Toolset beyond realtime manual manipulation of sounds. 3DMIDIVisualiser: An application to allow the user to work without access to a multi-speaker system by enabling the movement of sounds to be viewed within a virtual room. Foot Puck: Afoot-controlled panning controller enabling a musician to spatialise their instrument using foot movement. Initial prototyping was achieved using Cycling `74's Max/MSP but the final applications are written using Apple's Cocoa environment and Objective C. This thesis gives close analysis and discussion of the various stages of research carried out; including the use of Apple's CoreMlDl and CoreAudio Clock OS X Core Services in a Cocoa application.
3
Slysz, Rémi. "Reconstruction de surface 3D d'objets vivants". Thesis, Troyes, 2014. http://www.theses.fr/2014TROY0022/document.
Testo completoAbstract (sommario):
Cette thèse s'inscrit dans le cadre du projet CPER Bramms, dont un des objectifs était de développer une méthode d'acquisition de la surface du buste féminin. Les travaux menés ont donc eu pour but la conception, le développement et la réalisation d'une machine de mesure tridimensionnelle adaptée aux objets vivants. Parmi le nombre important de méthodes de mesures tridimensionnelles existantes, l'attention a été portée sur la mise en correspondance par stéréovision ainsi que sur l'utilisation de lumière structurée. La mise en correspondance par stéréovision consiste à retrouver les pixels homologues dans deux images d'une même scène, prise de deux points de vue différents. Une des manières de réaliser la mise en correspondance est de faire appel à des mesures de corrélation. Les algorithmes utilisés se heurtent alors à certaines difficultés : les changements de luminosité, les bruits, les déformations, les occultations, les zones peu texturées et les larges zones homogènes. L'utilisation de lumière structurée a permis essentiellement d'ajouter de l'information dans les zones homogènes lors des travaux menés. En développant cette approche, une méthode de reconstruction originale basée sur l'exploitation d'un motif particulier projeté sur la surface a ainsi été conçue. Un appariement basé sur la comparaison de signatures de points particuliers du motif a été mis en place. Ce procédé permet une reconstruction éparse en une unique acquisition et simplifie l'étape de gestion du nuage de points pour en faire un maillage surfaciqueThis thesis is part of the CPER BRAMSS project, one of its objectives was to develop an surface's retrieval method applied to the female bust. Therefore the work has aimed at the design, development and implementation of a three-dimensional measuring machine adapted to living objects.Among the large number of existing methods of three-dimensional measurements, attention was paid to the stereo matching as well as the use of structured light. Matching in stereovision is to find homologous pixels in two images of the same scene, taken from two different points of view. One way to achieve the mapping is to use correlation measurements. The algorithms used come up against certain difficulties: the changing light, noises, distortions, occlusions, low textured areas and large homogeneous areas. The use of structured light allow essentially the adding of information in homogeneous areas in this work. Developing this approach, an original method of reconstruction based on the exploitation of a particular pattern projected on the surface has been designed. A matching based on a comparison of the signatures of specific points in the pattern was implemented. This method allows a single sparse reconstruction acquisition step and simplifies the handling of the point cloud when transforming it in a surface mesh
4
FAUSZ, JAMES K. "EXPLORING PUBLIC INVOLVEMENT THROUGH PHOTOGRAPHY AND INTERACTIVE DESIGN". University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1147629903.
Testo completo
5
Lee, Won Hee. "Bundle block adjustment using 3D natural cubic splines". Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1211476222.
Testo completo
6
El-Hajjaji, Abdellah. "Traitement numérique en 3D d'un couple d'images stéréo du satellite SPOT". Rouen, 1993. http://www.theses.fr/1993ROUES028.
Testo completoAbstract (sommario):
L'objectif de notre recherche est d'extraire les altitudes h d'une scène donnée prise en image sous deux angles différents donnés par le satellite SPOT. Dans ce but nous avons modélisé le mouvement du satellite et de son système optique afin de transformer les deux images initiales en images épipolaires, ce qui nous permettra de réduire le temps d'appariement et de trouver les pixels homologues avec succès. Pour la mise en correspondance, nous avons utilisé une technique qui est à base de la corrélation et de la programmation dynamique. Cette méthode nous a permet d'apparier 96 % des pixels homologues avec une erreur inférieure à 5 mètres. Ce problème de mise en correspondance reste toujours ouvertThe aim of our research was to extract the level h of a precise landscape taken over two differents angles by the satellite SPOT. To do so, we have modelised the movement of the satellite and his optical system to transform the two first images in another one, epipolar which will allow us to reduce the matching time and to find with success the equivalent pixels. For the pairing, we have utilised a technic wich is based on the corrolation and of the dynamic programming. This method was very satisfactory and allow us to match 96 % of the equivalent pixels, with an error of less than 5 meters, but the original problem is still a matter of research for complimentary studing
7
Abranches, Gonçalo Botelho de Sousa. "Determinação da qualidade geométrica de superfície refletoras com recurso à fotogrametria". Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/23893.
Testo completoAbstract (sommario):
Neste trabalho é utilizada a Fotogrametria como ferramenta para avaliação geométrica de concentradores solares térmicos. Coletores do tipo cpc – coletores parabólicos compostos são submetidos a diversas experiências fotogramétricas e avaliados quanto à sua forma. Outros objetos com superfícies refletoras e não refletoras como concentradores solares ptc – parabolic through concentrator e fornos solares também são alvo de experiências fotogramétricas com o objetivo de estudar os efeitos de diferentes tipos de superfícies na fotogrametria.
É também comparado o modelo 3D do concentrador ideal com aquele que foi obtido através da fotogrametria, para o que foi feito um estudo exaustivo, verificando as diferenças geométricas entre os dois modelos, bem como os efeitos dessas diferenças físicas na reflexão dos raios solares, ou seja, na energia captada pelo concentrador; Abstract:
Geometrical assessment of reflective surfaces using photogrammetry
This paper uses Photogrammetry as a tool for the geometric evaluation of solar concentrators. Collectors of the cpc type - compound parabolic collectors are submitted to several photogrammetric experiments and evaluated for their shape. Other objects with reflecting and non-reflecting surfaces such as ptc - parabolic through concentrators and solar ovens are also the subject of photogrammetric experiments to study the effects of different types of surfaces in photogrammetry.
There is also a comparison between the 3D model of the ideal concentrator and that obtained by photogrammetry. An exhaustive study was done verifying the geometric differences between the two models as well as the effects of these physical differences in the reflection of the solar rays that represent the energy captured by the concentrator.
8
Silva, Roger Correia Pinheiro. "Desenvolvimento e análise de um digitalizador câmera-projetor de alta definição para captura de geometria e fotometria". Universidade Federal de Juiz de Fora (UFJF), 2011. https://repositorio.ufjf.br/jspui/handle/ufjf/3515.
Testo completoAbstract (sommario):
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-03-02T14:44:36Z
No. of bitstreams: 1
rogercorreiapinheirosilva.pdf: 22838442 bytes, checksum: 0bd115f462fc7572058a542e9ed91fcc (MD5)Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-06T19:52:42Z (GMT) No. of bitstreams: 1 rogercorreiapinheirosilva.pdf: 22838442 bytes, checksum: 0bd115f462fc7572058a542e9ed91fcc (MD5)
Made available in DSpace on 2017-03-06T19:52:42Z (GMT). No. of bitstreams: 1 rogercorreiapinheirosilva.pdf: 22838442 bytes, checksum: 0bd115f462fc7572058a542e9ed91fcc (MD5) Previous issue date: 2011-08-26
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Um sistema câmera-projetor é capaz de capturar informação geométrica tridimensional de objetos e ambientes do mundo real. A captura de geometria em tal sistema baseia-se na projeção de luz estruturada sobre um objeto através do projetor, e na captura da cena modulada através da câmera. Com o sistema previamente calibrado, a deformação da luz projetada causada pelo objeto fornece a informação necessária para reconstruir a geometria do mesmo por meio de triangulação. Este trabalho descreve o desenvolvimento de um digitalizador câmera-projetor de alta definição (com resoluções de até 1920x1080 e 1280x720); são detalhadas as etapas e processos que conduzem à reconstrução de geometria, como calibração câmera-projetor, calibração de cores, processamento da imagem capturada e triangulação. O digitalizador desenvolvido utiliza a codificação de luz estruturada (b; s)-BCSL, que emprega a projeção de uma sequência de faixas verticais coloridas sobre a cena. Este esquema de codificação flexível oferece um número variado de faixas para projeção: quanto maior o número de faixas, mais detalhada a geometria capturada. Um dos objetivos deste trabalho é estimar o número limite de faixas (b,s)-BCSL possível dentro das resoluções atuais de vídeo de alta definição. Este número limite é aquele que provê reconstrução densa da geometria alvo, e ao mesmo tempo possui baixo nível de erro. Para avaliar a geometria reconstruída pelo digitalizador para os diversos números de faixas, é proposto um protocolo para avaliação de erro. O protocolo desenvolvido utiliza planos como objetos para mensurar a qualidade de reconstrução geométrica. A partir da nuvem de pontos gerada pelo digitalizador, a equação do plano para a mesma é estimada por meio de mínimos quadrados. Para um número fixo de faixas, são feitas cinco digitalizações independentes do plano: cada digitalização leva a uma equação; também é computado o plano médio, estimado a partir da união das cinco nuvens de pontos. Uma métrica de distância no espaço projetivo é usada para avaliar a precisão e a acurácia de cada número de faixas projetados. Além da avaliação quantitativa, a geometria de vários objetos é apresentada para uma avaliação qualitativa. Os resultados demonstram que a quantidade de faixas limite para vídeos de alta resolução permite uma grande densidade de pontos mesmo em superfícies com alta variação de cores.
A camera-projector system is capable of capturing three-dimensional geometric information of objects and real-world environments. The capture of geometry in such system is based on the projection of structured light over an object by the projector, and the capture of the modulated scene through the camera. With a calibrated system, the deformation of the projected light caused by the object provides the information needed to reconstruct its geometry through triangulation. The present work describes the development of a high definition camera-projector system (with resolutions up to 1920x1080 and 1280x720). The steps and processes that lead to the reconstruction of geometry, such as camera-projector calibration, color calibration, image processing and triangulation, are detailed. The developed scanner uses the (b; s)-BCSL structured light coding, which employs the projection of a sequence of colored vertical stripes on the scene. This coding scheme offers a flexible number of stripes for projection: the higher the number of stripes, more detailed is the captured geometry. One of the objectives of this work is to estimate the limit number of (b; s)-BCSL stripes possible within the current resolutions of high definition video. This limit number is the one that provides dense geometry reconstruction, and at the same has low error. To evaluate the geometry reconstructed by the scanner for a different number of stripes, we propose a protocol for error measurement. The developed protocol uses planes as objects to measure the quality of geometric reconstruction. From the point cloud generated by the scanner, the equation for the same plane is estimated by least squares. For a fixed number of stripes, five independent scans are made for the plane: each scan leads to one equation; the median plane, estimated from the union of the five clouds of points, is also computed. A distance metric in the projective space is used to evaluate the precision and the accuracy of each number of projected stripes. In addition to the quantitative evaluation, the geometry of many objects are presented for qualitative evaluation. The results show that the limit number of stripes for high resolution video allows high density of points even on surfaces with high color variation.
9
Marques, Clarissa Codá dos Santos Cavalcanti. "Um sistema de calibração de câmera". Universidade Federal de Alagoas, 2007. http://repositorio.ufal.br/handle/riufal/1051.
Testo completoAbstract (sommario):
A camera calibration procedure corresponds to determine the digital geometric and
optical characteristics of the camera from a known initial data set. This problem can
be divided into three steps: a) acquisition of initial data; b) calibration process itself;
and c) optimization. This work presents the development of a calibration tool based on
a generic architecture for any calibration approach. For this aim, the presented system
allows the personalization of each calibration step. In the proposed tool new calibration
procedures are introduced dynamically, allowing a better integration between the modules
of the system.Fundação de Amparo a Pesquisa do Estado de Alagoas
Um processo de calibração de câmera consiste no problema de determinar as características geométricas digitais e ópticas da câmera a partir de um conjunto de dados iniciais. Este problema pode ser dividido em três etapas: aquisição de dados iniciais, o processo de calibração em si e otimização. Este trabalho propõe o desenvolvimento de uma ferramenta de calibração baseada em uma arquitetura genérica para qualquer processo de calibração. Para este propósito, o sistema apresentado neste trabalho permite a personalização de cada etapa da calibração. A inclusão de novos métodos de calibração é realizada de forma dinâmica, permitindo assim maior integração e flexibilidade entre os módulos do sistema.
10
Hudec, Jiří. "Vizualizace výrobních podkladů ve firmě IFE Brno". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229956.
Testo completoAbstract (sommario):
This thesis deals with the effectivity of the work procedure visualisations. This thesis describes basic programs used for work procedure visualisation in the IFE company. The example of a product and following time sequences shows how time -efficient the use of visualized procedures is. The final focus of the thesis is on improving work procedures by using 3D models for simpler assembly procedures and preassembly procedures.
11
Choi, Keum-Ran. "3D thermal mapping of cone calorimeter specimen and development of a heat flux mapping procedure utilizing an infrared camera". Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-020205-215634/.
Testo completoAbstract (sommario):
Dissertation (Ph.D.)-- Worcester Polytechnic Institute.Keywords: temperature measurement; heat flux maps; Cone Calorimeter; three-dimensional heat conduction; fire growth models; retainer frame; ceramic fiberboard; edge effect; one-dimensional heat conduction; heat flux mapping procedure; infrared camera; specimen preparation; edge frame; one-dimensional heat conduction model; thermal properties. Includes bibliographical references (p.202-204).
12
Banerjee, Natasha Kholgade. "3D Manipulation of Objects in Photographs". Research Showcase @ CMU, 2015. http://repository.cmu.edu/dissertations/659.
Testo completoAbstract (sommario):
This thesis describes a system that allows users to to perform full three-dimensional manipulations to objects in photographs. Cameras and photo-editing tools have contributed to the explosion in creative content by democratizing the process of creating visual realizations of users’ imaginations. However, shooting photographs using a camera is constrained by real-world physics, while existing photo-editing software is largely restricted to the 2D plane of the image. 3D object edits, intuitive to humans, are simply not possible in photo-editing software. The fundamental challenge in providing 3D object manipulation is that estimating the 3D structure of the object, including the geometry and appearance of object parts hidden from the viewpoint of the camera is ill-posed. 3D object manipulations reveal hidden parts of objects that were not previously seen from the viewpoint of the camera. The key contributions of this thesis are algorithms that leverage 3D models from public repositories to obtain a three-dimensional representation of objects in photographs for 3D manipulation with seamless transition in appearance of the object from the original photograph. 3D models of objects in online repositories cannot be directly used to manipulate photographed objects, as they show mismatches in geometry and appearance, and do not contain three-dimensional illumination representing the scene where the photograph was captured. The work in this thesis provides a system that align the 3D model geometry, estimates three-dimensional illumination, and completes the appearance over the object in three dimensions to provide full 3D manipulation. To correct the mismatch between the geometry of the 3D model and the photographed object, the thesis presents an automatic model alignment technique that performs an exhaustive search in the space of viewpoint, object location, scale, and non-rigid deformation. We also provide a manual geometry adjustment tool that allows users to perform final corrections while imposing smoothness and symmetry constraints. Given the matched geometry, we present an illumination estimation approach that uses the visible pixels to obtain three-dimensional environment illumination that produces plausible effects such as cast shadows and smooth surface shading. Our appearance completion approach relates visible parts of the object to hidden parts using symmetries over the publicly available 3D model. Our interactive system for editing photographs re-imagines typical photo-editing operations such as rotation, translation, copy-paste, scaling, and deformation as 3D manipulations to objects. Using our system, users have created a variety of manipulations to photographs, such as flipping cars, making dynamic compositions of multiple objects suspended in the air, performing animations, and altering the stories of historical images and personal photographs.
13
Shlyakhter, Ilya 1975, e Max 1976 Rozenoer. "Reconstruction of 3D tree models from instrumented photographs". Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80136.
Testo completoAbstract (sommario):
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Also issued with order of names reversed on t.p.
Includes bibliographical references (leaves 33-36).
by Ilya Shlyakhter and Max Rozenoer.
M.Eng.
14
Vesna, Stojaković. "Generisanje prostora na osnovu perspektivnih slika i primena u oblasti graditeljskog nasleđa". Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2011. http://dx.doi.org/10.2298/NS20110816STOJAKOVIC.
Testo completoAbstract (sommario):
U ovom radu kreiran je novi poluautomatski normativni sistem za generisanje prostora na osnovu perspektivnih slika. Sistem obuhvata niz postupaka čijim korišćenjem se na osnovu dvodimenzionalnih medijuma, najčešće fotografija, generiše trodimenzionalna struktura. Pristup je prilagođen rešavanju složenih problema iz oblasti vizuelizacije graditeljskog nasleđa, što je u radu potkrepljeno praktičnom primenom sistema.In this research a new semi-automated normative image-based modelling system is created. The system includes number of procedures that are used to transform two-dimensional medium, such as photographs, to threedimensional structure. The used approach is adjusted to the properties of complex projects in the domain of visualization of cultural heritage. An application of the system is given demonstrating its practical value.
15
Persson, Thom. "Building of a Stereo Camera System". Thesis, Blekinge Tekniska Högskola, Avdelningen för signalbehandling, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3579.
Testo completoAbstract (sommario):
This project consists of a prototype of a stereo camera rig where you can mount two DSLR cameras, and a multithreaded software application, written in C++, that can move the cameras, change camera settings and take pictures. The resulting 3D-images can be viewed with a 2-view autostereoscopic display. Camera position is controlled by a step engine which is controlled by a PIC microcontroller. All communication with the PIC and the computer is made over USB. The camera shutters are synchronized so it is possible to take pictures of moving objects at a distance of 2.5 m or more. The results shows that there are several things to do before the prototype can be considered a product ready for the market, most of all the camera callback functionality.Detta projekt består av en stereokamerarigg som kan bestyckas med två DSLR-kameror, samt en applikation indelad i flera trådar (multithreaded) , skriven i C++, som kan förflytta kamerorna på riggen, ändra fotoinställningar och ra bilder. Resultatet blir 3D-bilder som kan ses på en autostereoskopisk skärm. Kamerornas position kontrolleras med en stegmotor, som i sin tur styrs av en PIC-mikrokontroller. Kommunikationen mellan PIC-enheten och datorn sker via USB. Slutarna på kamerorna är synkroniserade så det är möjligt att ta bilder på objekt i rörelse på ett avstånd av 2,5 m eller mer. Resultaten visar att det är flera punkter som måste åtgärdas på prototypen innan den kan anses vara redo för marknaden. Den viktigaste punkten är att kunna få fungerande respons (callback) från kamerorna.
16
Lin, Wei-Ming. "Constructing a GIS-based 3D urban model using LiDAR and aerial photographs". Texas A&M University, 2004. http://hdl.handle.net/1969.1/1495.
Testo completoAbstract (sommario):
Due to the increasing availability of high-resolution remotely sensed
imagery and detailed terrain surface elevation models, urban planners and
municipal managers can now model and visualize the urban space in three
dimensions. The traditional approach to the representation of urban space is 2D
planimetric maps with building footprints, facilities and road networks.
Recently, a number of methods have been developed to represent true 3D urban
models. Those include panoramic imaging, Virtual Reality Modeling Language
(VRML), and Computer-aided Design (CAD). These methods focus on aesthetic
representation, but they do not have sufficient spatial query and analytical
capabilities.
This research evaluates the conventional approaches to 3D urban models,
and identifies their advantages and limitations; GIS functionalities have been
combined with 3D urban visualization techniques to develop a GIS-based urban
modeling method; The algorithms and techniques have been explored to derive
urban objects and their attributes from airborne LiDAR and high-resolution
imagery for constructing and visualizing 3D urban models; and 3D urban
models for the Texas A&M University (TAMU) campus and downtown
Houston have been implemented using the algorithms and techniques
developed in this research. By adding close-range camera images and highresolution
aerial photographs as the texture of urban objects, effect of
photorealism visualization has been achieved for walk-through and fly-through
animations.
The Texas A&M University campus model and the downtown Houston
model have been implemented to offer proof-of-concept, namely, to
demonstrate the advantages of the GIS-based approach. These two prototype
applications show that the GIS-based 3D urban modeling method, by coupling
ArcGIS and MultiGen-Paradigm Site Builder 3D software, can realize the
desired functionalities in georeferencing, geographical measurements, spatial
query, spatial analysis, and numerical modeling in 3D visual environment.
17
Parmentier, Alain. "Acquisition de cartes denses pour la génération et le contrôle de formes vestimentaires". Valenciennes, 1994. https://ged.uphf.fr/nuxeo/site/esupversions/96d52b8e-37f9-4146-8eaf-405f79a9426f.
Testo completoAbstract (sommario):
Cet expose concerne une application au contrôle de formes vestimentaires en confection. Un premier chapitre décrit des aspects liés au cadre d'application. L'élasticité, la souplesse des formes vestimentaires interdisent tout contrôle impliquant des palpeurs mécaniques. Un second chapitre consacre un état de l'art a des méthodes optiques ou ultrasonores. Un plan de traçage optique est retenu afin de contrôler des régions vestimentaires, à lentes variations de courbure et a réflectances lambertiennes. La pupille de sortie du montage, qui élargit un faisceau laser en un plan lumineux, s'apparente à une fente fine qui diffracte à l'infini. Décrit dans un troisième chapitre, le protocole expérimental présente plus particulièrement un atelier photographique, un calibre de formes et des modes d'habillage adaptés aux comportements textiles des tissus étudiés. Malgré un faible équipement, la production photographique est adaptée a des contraintes spécifiques. Un quatrième chapitre présente des outils de contrôle photographique et d'analyse d'images. La granularité laser affecte les images des motifs de lumière structurée. Localement, l'image de la trace du plan laser est identifiée par une corde. Cette approximation implique une discrimination radiométrique selon une loi statistique. Un filtrage morphologique permet d'isoler efficacement les images des motifs de lumière structurée. Un cinquième chapitre présente un environnement industriel logiciel requis par la conduite d'une application prototype, une évaluation expérimentale en fonction d'états de surfaces vestimentaires et des perspectives de développement. Indépendamment de leurs états de surfaces, le contrôle de formes vestimentaires dépend de spécifications morphologiques appropriées à des types de vêtements.
18
Cooper, Joseph L. "Supporting Flight Control for UAV-Assisted Wilderness Search and Rescue Through Human Centered Interface Design". Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2140.pdf.
Testo completo
19
Viktora, Jakub. "Využití fotogrammetrie pro realitní praxi". Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-233074.
Testo completoAbstract (sommario):
This diploma thesis aims to explore possibilities of using IT in real estate and projection practice. It deals with simplification of difficult or insolvable tasks. It focuses on rapidly developing field of photogrammetry and its further processing via software. The work presents methods of measurement of existing realties without using standard methods (tape line, laser). Instead of these tools, the author uses photographic data and program PhotoModeler for surveying and creating a 3D model of the facade. The thesis verifies further serviceability of gained data up to the render phase of the surveyed building facade.
20
Schindler, Grant. "Unlocking the urban photographic record through 4D scene modeling". Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34719.
Testo completoAbstract (sommario):
Vast collections of historical photographs are being digitally archived and placed online, providing an objective record of the last two centuries that remains largely untapped. We propose that time-varying 3D models can pull together and index large collections of images while also serving as a tool of historical discovery, revealing new information about the locations, dates, and contents of historical images. In particular, our goal is to use computer vision techniques to tie together a large set of historical photographs of a given city into a consistent 4D model of the city: a 3D model with time as an additional dimension.
To extract 4D city models from historical images, we must perform inference about the position of cameras and scene structure in both space and time. Traditional structure from motion techniques can be used to deal with the spatial problem, while here we focus on the problem of inferring temporal information: a date for each image and a time interval for which each structural element in the scene persists.
We first formulate this task as a constraint satisfaction problem based on the visibility of structural elements in each image, resulting in a temporal ordering of images. Next, we present methods to incorporate real date information into the temporal inference solution. Finally, we present a general probabilistic framework for estimating all temporal variables in structure from motion problems, including an unknown date for each camera and an unknown time interval for each structural element. Given a collection of images with mostly unknown or uncertain dates, we can use this framework to automatically recover the dates of all images by reasoning probabilistically about the visibility and existence of objects in the scene. We present results for image collections consisting of hundreds of historical images of cities taken over decades of time, including Manhattan and downtown Atlanta.
21
Dupont, de Dinechin Grégoire. "Towards comfortable virtual reality viewing of virtual environments created from photographs of the real world". Thesis, Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLM049.
Testo completoAbstract (sommario):
La reconstitution en réalité virtuelle de lieux, personnes, et objets réels ouvre la voie à de nombreux usages, tels que préserver et promouvoir des sites culturels, générer des avatars photoréalistes pour se retrouver virtuellement avec famille et amis à distance, ou encore recréer des lieux ou situations spécifiques à des fins thérapeutiques ou de formation. Tout cela s'appuie sur notre capacité à transformer des images du monde réel (photos et vidéos) en environnements 360° immersifs et objets 3D interactifs. Cependant, ces environnements virtuels à base d'images demeurent souvent imparfaits, et peuvent ainsi rendre le visionnage en réalité virtuelle inconfortable pour les utilisateurs. En particulier, il est difficile de reconstituer avec précision la géométrie d'une scène réelle, et souvent de nombreuses approximations sont ainsi faites qui peuvent être source d'inconfort lors de l'observation ou du déplacement. De même, il est difficile de restituer fidèlement l'aspect visuel de la scène : les méthodes classiques ne peuvent ainsi restituer certains effets visuels complexes tels que transparence et réflexions spéculaires, tandis que les algorithmes de rendu plus spécialisés ont tendance à générer des artefacts visuels et peuvent être source de latence. Par ailleurs, ces problèmes deviennent d'autant plus complexes lorsqu'il s'agit de reconstituer des personnes, l'oeil humain étant très sensible aux défauts dans l'apparence ou le comportement de personnages virtuels. Par conséquent, l'objectif de cette thèse est d'étudier les méthodes permettant de rendre les utilisateurs plus confortables lors du visionnage immersif de reconstitutions digitales du monde réel, par l'amélioration et le développement de nouvelles méthodes de création d'environnements virtuels à partir de photos. Nous démontrons et évaluons ainsi des solutions permettant (1) de fournir une meilleure parallaxe de mouvement lors du visionnage d'images 360°, par le biais d'une interface immersive pour l'estimation de cartes de profondeur, (2) de générer automatiquement des agents virtuels 3D capables d'interaction à partir de vidéos 360°, en combinant des modèles pré-entrainés d'apprentissage profond, et (3) de restituer des effets visuels de façon photoréaliste en réalité virtuelle, par le développement d'outils que nous appliquons ensuite pour recréer virtuellement la collection d'un musée de minéralogie. Nous évaluons chaque approche par le biais d'études utilisateur, et rendons notre code accessible sous forme d'outils open sourceThere are many applications to capturing and digitally recreating real-world people and places for virtual reality (VR), such as preserving and promoting cultural heritage sites, placing users face-to-face with faraway family and friends, and creating photorealistic replicas of specific locations for therapy and training. This is typically done by transforming sets of input images, i.e. photographs and videos, into immersive 360° scenes and interactive 3D objects. However, such image-based virtual environments are often flawed such that they fail to provide users with a comfortable viewing experience. In particular, accurately recovering the scene's 3D geometry is a difficult task, causing many existing approaches to make approximations that are likely to cause discomfort, e.g. as the scene appears distorted or seems to move with the viewer during head motion. In the same way, existing solutions most often fail to accurately render the scene's visual appearance in a comfortable fashion. Standard 3D reconstruction pipelines thus commonly average out captured view-dependent effects such as specular reflections, whereas complex image-based rendering algorithms often fail to achieve VR-compatible framerates, and are likely to cause distracting visual artifacts outside of a small range of head motion. Finally, further complications arise when the goal is to virtually recreate people, as inaccuracies in the appearance of the displayed 3D characters or unconvincing responsive behavior may be additional sources of unease. Therefore, in this thesis, we investigate the extent to which users can be made more comfortable when viewing digital replicas of the real world in VR, by enhancing, combining, and designing new solutions for creating virtual environments from input sets of photographs. We thus demonstrate and evaluate solutions for (1) providing motion parallax during the viewing of 360° images, using a VR interface for estimating depth information, (2) automatically generating responsive 3D virtual agents from 360° videos, by combining pre-trained deep learning networks, and (3) rendering captured view-dependent effects at high framerates in a game engine widely used for VR development, which we apply to digitally recreate a museum's mineralogy collection. We evaluate and discuss each approach by way of user studies, and make our codebase available as an open-source toolkit
22
Tournaire, Olivier. "Extraction 3D de marquages routiers à partir d'images aériennes multi-vues et quelques applications". Marne-la-Vallée, 2007. http://www.theses.fr/2007MARN0368.
Testo completoAbstract (sommario):
La détection de routes à partir d’images aéroportées ou d’images satellitales et RADAR est un thème d’intérêt majeur qui a mobilisé de nombreux chercheurs depuis la fin des années 1970. Le sujet reste encore aujourd’hui largement d’actualité, d’autant que les besoins de données fiables et récentes sont toujours plus importants. Dans le cadre de cette thèse, nous envisageons le réseau routier sous un angle restreint, celui de la détection d’objets du sol, et, plus précisément, de la signalisation routière horizontale, c’est-à-dire le marquage au sol. Les données que nous utiliserons sont des images aériennes à haute résolution (de l’ordre de 25 cm au nadir) dans un contexte multi-recouvrement. L’accent sera mis tout particulièrement sur le milieu urbain. Nous présenterons dans ce manuscrit les travaux que nous avons menés dans cette optique. Nous avons retenu un découpage qui se focalise dans un premier temps sur les objets du marquage au sol que nous proposons de détecter et de reconstruire dans un espace tridimensionnel. Dans ce contexte, la méthodologie générale sera précisée : détection et sélection des primitives image, puis, reconstruction de primitives 3D. La première approche bottomup sera ensuite confrontée à une approche top-down par processus ponctuels marqués. Cette approche permet en effet de s’affranchir d’un certain nombre de problèmes inhérents aux premières méthodes que nous présenterons, par l’introduction de connaissances a priori. A partir des résultats obtenus, nous présenterons une méthodologie permettant d’améliorer la qualité géométrique des objets reconstruits. L’ensemble de ces étapes sera basé sur un ensemble de spécifications géométriques et d’implantation clairement définies par les services en charge de la voirie. Dans un second temps, nous avons cherché à mettre en lumière l’intérêt de ces travaux dans diverses applications. En effet, outre l’aspect purement informatif sur la structure du réseau routier que permettent de définir les marquages au sol, il est possible d’en dériver des données utilisables dans d’autres processus. Nous présenterons en premier lieu une méthode permettant de réaliser un géoréférencement fin des images acquises par un système de cartographie mobile en milieu urbain. Les problèmes de géolocalisation de tels systèmes (masques et multi-trajets des signaux GPS) peuvent être résolus par l’appariement d’objets détectés par les systèmes imageurs aérien et terrestre. Cette méthode permet ainsi de bénéficier de la qualité géométrique des objets issus de l’imagerie terrestre et de la qualité de localisation des objets reconstruits à partir des images aériennes. Nous nous intéresserons ensuite à la détection et à la délimitation de routes à partir de graines calculées automatiquement grâce aux marquages au sol détectés et reconstruits. Ces graines sont ensuite utilisées dans un algorithme de croissance de régionsRoad detection from aerial, satellital or RADAR images is of great interest in the image processing and photogrammetric communities since the 70’s. This topic stays today challenging, the growing needs for accurate and recent data being more and more important. In the context of this work, we study the road network in a restrictive frame, the one of the horizontal road signs, i. E. Road markings. For this purpose, we will use high resolution aerial images (25 cm GSD), in a multiview frame. We will particularly emphasize on the urban environment. In this thesis, we will present the works done according to this point of view. We choose to focus first on the road markings objects that we propose to detect and reconstruct in a three dimensional space. In this context, the general strategy will be developped : detection and selection of images features, then, three dimensionnal reconstruction. The first bottomup approach will then be compare with with a top-down approach involving marked point processes. This approach enables to cope with some of the problems inherents to the first methods we will present, with the introduction of a priori knowledge. From the obtained results, we will present a methodology allowing us to increase geometric quality of the reconstructed objects. All those steps are based on a set of specifications describing clearly and carefully the geometric shapes of the road markings coming from public road services. In a second time, we tried to highlight the sake of these works in miscellaneous applications. Indeed, in addition to the purely informative aspect on the road network structure derived from the road markings, it is possible to branch off from them data usefull in other processes. We first present a method to obtain a fine georeferencing of images acquired with mobile mapping systems in urban areas. The location problems of such systems (masks and multipaths of GPS signal) can be solved with matching objects detected from both aerial and terrestrial imaging systems. This method enables to benefit jointly from the geometric quality of the objets coming from the terrestrial imagery and of the location quality of the objects reconstructed from aerial images. We will then focus of the detection and delimitation of roads from seeds automatically computed thanks to the detected and reconstructed road markings. These seeds are then introduced in a region growing algorithm
23
Deák, Jaromír. "Registrace fotografií do 3D modelu terénu". Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2017. http://www.nusl.cz/ntk/nusl-363795.
Testo completoAbstract (sommario):
This work refers existing solutions and options for the task registration of photos to 3D model based on the previous knowledge of the geographic position of the camera. The contribution of the work are new ways and possibilities of the solution with the usage of graph algorithms. In this area, the work interests are useful points of interest detection in input data, a construction of graphs and graph matching possibilities.
24
Slomp, Marcos Paulo Berteli. "Real-time photographic local tone reproduction using summed-area tables". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/34766.
Testo completoAbstract (sommario):
A síntese de imagens com alta faixa dinâmica é uma prática cada vez mais comum em computação gráfica. O desafio consiste em relacionar o grande conjunto de intensidades da imagem sintetizada com um sub-conjunto muito inferior suportado por um dispositivo de exibição, evitando a perda de detalhes contrastivos. Os operadores locais de reprodução de tons (local tone-mapping operators) são capazes de realizar tal compressão, adaptando o nível de luminância de cada pixel com respeito à sua vizinhança. Embora produzam resultados significativamente superiores aos operadores globais, o custo computacional é consideravelmente maior, o que vem impedindo sua utilização em aplicações em tempo real. Este trabalho apresenta uma técnica para aproximar o operador fotográfico local de reprodução de tons. Todas as etapas da técnica são implementadas em GPU, adequando-se ao cenário de aplicações em tempo real, sendo significativamente mais rápida que implementações existentes e produzindo resultados semelhantes. A abordagem é baseada no uso de tabelas de áreas acumuladas (summed-area tables) para acelerar a convolução das vizinhanças, usando filtros da média (box-filter), proporcionando uma solução elegante para aplicações que utilizam imagens em alta faixa dinâmica e que necessitam de performance sem comprometer a qualidade da imagem sintetizada. Uma investigação sobre algoritmos para a geração de somatórios pré-fixados (prefix sum) e uma possível melhoria para um deles também são apresentada.High dynamic range (HDR) rendering is becoming an increasingly popular technique in computer graphics. Its challenge consists on mapping the resulting images’ large range of intensities to the much narrower ones of the display devices in a way that preserves contrastive details. Local tone-mapping operators effectively perform the required compression by adapting the luminance level of each pixel with respect to its neighborhood. While they generate significantly better results when compared to global operators, their computational costs are considerably higher, thus preventing their use in real-time applications. This work presents a real-time technique for approximating the photographic local tone reproduction that runs entirely on the GPU and is significantly faster than existing implementations that produce similar results. Our approach is based on the use of summed-area tables for accelerating the convolution of the local neighborhoods with a box filter and provides an attractive solution for HDR rendering applications that require high performance without compromising image quality. A survey of prefix sum algorithms and possible improvements are also presented.
25
Poulin-Girard, Anne-Sophie. "Paire stéréoscopique Panomorphe pour la reconstruction 3D d'objets d'intérêt dans une scène". Doctoral thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27073.
Testo completoAbstract (sommario):
Il existe désormais une grande variété de lentilles panoramiques disponibles sur le marché dont certaines présentant des caractéristiques étonnantes. Faisant partie de cette dernière catégorie, les lentilles Panomorphes sont des lentilles panoramiques anamorphiques dont le profil de distorsion est fortement non-uniforme, ce qui cause la présence de zones de grandissement augmenté dans le champ de vue. Dans un contexte de robotique mobile, ces particularités peuvent être exploitées dans des systèmes stéréoscopiques pour la reconstruction 3D d’objets d’intérêt qui permettent à la fois une bonne connaissance de l’environnement, mais également l’accès à des détails plus fins en raison des zones de grandissement augmenté. Cependant, à cause de leur complexité, ces lentilles sont difficiles à calibrer et, à notre connaissance, aucune étude n’a réellement été menée à ce propos. L’objectif principal de cette thèse est la conception, l’élaboration et l’évaluation des performances de systèmes stéréoscopiques Panomorphes. Le calibrage a été effectué à l’aide d’une technique établie utilisant des cibles planes et d’une boîte à outils de calibrage dont l’usage est répandu. De plus, des techniques mathématiques nouvelles visant à rétablir la symétrie de révolution dans l’image (cercle) et à uniformiser la longueur focale (cercle uniforme) ont été développées pour voir s’il était possible d’ainsi faciliter le calibrage. Dans un premier temps, le champ de vue a été divisé en zones à l’intérieur desquelles la longueur focale instantanée varie peu et le calibrage a été effectué pour chacune d’entre elles. Puis, le calibrage général des systèmes a aussi été réalisé pour tout le champ de vue simultanément. Les résultats ont montré que la technique de calibrage par zone ne produit pas de gain significatif quant à la qualité des reconstructions 3D d’objet d’intérêt par rapport au calibrage général. Cependant, l’étude de cette nouvelle approche a permis de réaliser une évaluation des performances des systèmes stéréoscopiques Panomorphes sur tout le champ de vue et de montrer qu’il est possible d’effectuer des reconstructions 3D de qualité dans toutes les zones. De plus, la technique mathématique du cercle a produit des résultats de reconstructions 3D en général équivalents à l’utilisation des coordonnées originales. Puisqu’il existe des outils de calibrage qui, contrairement à celui utilisé dans ce travail, ne disposent que d’un seul degré de liberté sur la longueur focale, cette technique pourrait rendre possible le calibrage de lentilles Panomorphes à l’aide de ceux-ci. Finalement, certaines conclusions ont pu être dégagées quant aux facteurs déterminants influençant la qualité de la reconstruction 3D à l’aide de systèmes stéréoscopiques Panomorphes et aux caractéristiques à privilégier dans le choix des lentilles. La difficulté à calibrer les optiques Panomorphes en laboratoire a mené à l’élaboration d’une technique de calibrage virtuel utilisant un logiciel de conception optique et une boîte à outils de calibrage. Cette approche a permis d’effectuer des simulations en lien avec l’impact des conditions d’opération sur les paramètres de calibrage et avec l’effet des conditions de calibrage sur la qualité de la reconstruction. Des expérimentations de ce type sont pratiquement impossibles à réaliser en laboratoire mais représentent un intérêt certain pour les utilisateurs. Le calibrage virtuel d’une lentille traditionnelle a aussi montré que l’erreur de reprojection moyenne, couramment utilisée comme façon d’évaluer la qualité d’un calibrage, n’est pas nécessairement un indicateur fiable de la qualité de la reconstruction 3D. Il est alors nécessaire de disposer de données supplémentaires pour juger adéquatement de la qualité d’un calibrage.A wide variety of panoramic lenses are available on the market. Exhibiting interesting characteristics, the Panomorph lens is a panoramic anamorphic optical system. Its highly non-uniform distortion profile creates areas of enhanced magnification across the field of view. For mobile robotic applications, a stereoscopic system for 3D reconstruction of objects of interest could greatly benefit from the unique features of these special lenses. Such a stereoscopic system would provide general information describing the environment surrounding its navigation. Moreover, the areas of enhanced magnification give access to smaller details. However, the downfall is that Panomorph lenses are difficult to calibrate, and this is the main reason why no research has been carried out on this topic. The main goal of this thesis is the design and development of Panomorph stereoscopic systems as well as the evaluation of their performance. The calibration of the lenses was performed using plane targets and a well-established calibration toolbox. In addition, new mathematical techniques aiming to restore the symmetry of revolution in the image and to make the focal length uniform over the field of view were developed to simplify the calibration process. First, the field of view was divided into zones exhibiting a small variation of the focal length and the calibration was performed for each zone. Then, the general calibration was performed for the entire field of view. The results showed that the calibration of each zone does not lead to a better 3D reconstruction than the general calibration method. However, this new approach allowed a study of the quality of the reconstruction over the entire field of view. Indeed, it showed that is it possible to achieve good reconstruction for all the zones of the field of view. In addition, the results for the mathematical techniques used to restore the symmetry of revolution were similar to the results obtained with the original data. These techniques could therefore be used to calibrate Panomorph lenses with calibration toolboxes that do not have two degrees of freedom relating to the focal length. The study of the performance of stereoscopic Panomorph systems also highlighted important factors that could influence the choice of lenses and configuration for similar systems. The challenge met during the calibration of Panomorph lenses led to the development of a virtual calibration technique that used an optical design software and a calibration toolbox. With this technique, simulations reproducing the operating conditions were made to evaluate their impact on the calibration parameters. The quality of 3D reconstruction of a volume was also evaluated for various calibration conditions. Similar experiments would be extremely tedious to perform in the laboratory but the results are quite meaningful for the user. The virtual calibration of a traditional lens also showed that the mean reprojection error, often used to judge the quality of the calibration process, does not represent the quality of the 3D reconstruction. It is then essential to have access to more information in order to asses the quality of a lens calibration.
26
Rossi, Romain. "Reconstruction 3D volumétrique par vision omnidirectionnelle sur architecture massivement parallèle". Rouen, 2011. http://www.theses.fr/2011ROUES025.
Testo completoAbstract (sommario):
La reconstruction 3D d'une scène inconnue est un problème courant en ision par ordinateur. Les solutions classiques utilisant une paire de améras en configuration stéréoscopique et un algorithme exploitant les dsparités sur l'image ne permettent pas le calcul d'un modèle 3D dense égulièrement échantillonné. De plus, la réalisation de cette tâche en emps-réel est complexe et nécessite bien souvent une implémentation sur ircuits spécialisés (FPGA ou DSP) puissants mais difficiles à mettre en oeuvre. Dans ces travaux, nous proposons une méthode volumétrique ayant pour objectif une reconstruction en temps-réel d'un modèle 3D haute-résolution de l'environnement d'un robot mobile. Une paire de caméras catadioptriques permet l'acquisition panoramique de la scène. L'algorithme de reconstruction, adapté pour l'architecture massivement parallèle d'un processeur graphique (GPU), très puissant et peu coûteux, limite au maximum les dépendances de données menant à une séquentialisation du code et pénalisant les performances. La méthode de reconstruction proposée ici permet en plus d'exploiter de nouvelles images obtenues au fur et à mesure du déplacement du robot dans la scène, améliorant ainsi incrémentalement le modèle volumétrique avec de nouvelles données. Les résultats obtenus sont qualitativement proche de ceux obtenus par les méthodes classiques sur des scènes simples, mais notre approche permet une résolution du modèle 3D bien supérieure à l'état de l'art (500x500x200 voxels) tout en conservant une bonne rapidité d'exécution (environ 5 secondes par reconstruction). La cadence temps-réel (2 reconstructions par seconde) peut même être atteinte pour une résolution de modèle plus faible (150x150x150 voxels). Une expérimentation sur une scène réelle permet de valider l'approche développée avec une mise en situation réaliste3D reconstruction of an unknown scene is a classical computer vision problem. Usual solutions, which use a pair of cameras in stereoscopic configuration and an algorithm relying on image disparities, don't allow to create a densely sampled 3D model. Moreover, processing this model in real-time is a complex task which often needs an implementation on dedicated hardware (FPGA or DSP), very powerful but hard to use. In this thesis, we propose a volumetric reconstruction method aiming to produce a high-resolution 3D model of the scene surrounding a mobile robot. A pair of catadioptric cameras allows panoramic acquisition of the whole scene. The reconstruction algorithm, adapted for the massively-parallel architecture of a very powerful and inexpensive Graphical Processing Unit (GPU) tries to limit data-dependencies to improve performances. This reconstruction method also benefit from additional pictures, taken as the robot moves in the scene, to incrementally improve the 3D model. The final results are qualitatively equivalent to the ones obtained with classical methods, but our approach allows a 3D resolution far better (500x500x200 voxels) with a very short running time (about 5 seconds for each reconstruction). The real-time objective (2 reconstructions per second) can even be reached for a lower-resolution (150x150x150 voxels). Experimental results on a real image validate the proposed approach
27
Beauvivre, Stéphane. "Evaluation des performances de microcaméras réalisées en technologie 3D pour la mission spatiale cométaire ROSETTA". Montpellier 2, 1999. http://www.theses.fr/1999MON20037.
Testo completoAbstract (sommario):
Cette these presente l'evaluation des performances de prototypes de microcameras realisees en technologie d'encapsulation 3d et destinees a la mission cometaire rosetta de l'agence spatiale europeenne. Un ensemble de tests, pour lesquels des developpements electroniques et logiciels specifiques ont ete necessaires, a ete realise sur deux types de microcamera, a differentes temperatures : mesures electriques, metrologiques et photometriques. Les resultats obtenus montrent que les caracteristiques photometriques restent nominales et qu'elles n'evoluent pas dans la gamme de temperatures 90c a + 20c. La petite taille de la camera associee a son mode operatoire implique un fonctionnement en regime transitoire de temperature qui n'affecte cependant pas les proprietes des cameras lors de fonctionnement a des temperatures inferieures a 55c. Nous avons montre que ce type de camera miniature convient pour une mission spatiale telle que rosetta, sous reserve de porter attention aux problemes de conception electronique et mecanique qui peuvent se reveler critiques.
28
Chaibi, Yasmina. "Adaptation des méthodes de reconstruction 3D rapides par stéréoradiographie : Modélisation du membre inférieur et calcul des indices cliniques en présence de déformation structurale". Paris, ENSAM, 2010. http://www.theses.fr/2010ENAM0013.
Testo completoAbstract (sommario):
Le soudage par friction malaxage FSW est un procédé de soudage à l'état solide, sans fusion du matériau. La soudure est réalisée par l'action d'un outil composé d'un épaulement et d'un pion positionné à l'interface des deux pièces à souder. L'outil a deux rôles : échauffement de la matière par frottement de l'épaulement, malaxage de la matière par l'intermédiaire du pion. Ce travail de thèse s'inscrit dans le cadre d'un partenariat entre Arts et Métiers ParisTech et l'Institut de Soudure. Son objectif est de développer un modèle de simulation du FSW afin de réduire le nombre d'essais expérimentaux nécessaire à l'optimisation du procédé. Ainsi, plusieurs points ont été abordés dans ce manuscrit. Une analyse expérimentale des cycles thermiques et des mouvements de matière dans le cas où les pions sont non filetés a été menée. Cette situation permet (1) de faciliter la comparaison avec la simulation numérique et (2) de se placer dans les conditions de pions usés. L'analyse des formulations (lagrangienne, eulérienne et ALE) en vue de choisir celle la plus appropriée pour représenter les écoulements de matière a permis de retenir une formulation eulérienne (mise en œuvre dans le logiciel FLUENT) pour estimer les champs thermiques et de vitesses à l'état stationnaire. La mise en place d'un modèle numérique dans le logiciel FLUENT est présentée. Nous avons en particulier étudier l'influence des paramètres numériques sur les résultats et mis en place une stratégie d'identification de certains paramètres non accessibles expérimentalement. Une comparaison fine entre nos résultats expérimentaux et ceux issus des simulations a été effectuée avec succès. L'étude de l'impact des paramètres process (vitesse d'avance, vitesse de rotation) et de la géométrie du pion sur les champs thermiques et de vitesses a permis de mettre en évidence le lien entre les champs de vitesse et la présence de défauts de type tunnelThe Friction Stir Welding (FSW) is a solid state welding process, without melting. The weld is fabricated thanks to the action of tool made of a shoulder and a pin, positioned at the interface of the two pieces to be welded. The tool as two roles : heating of the material by friction of the shoulder, mixing of the material due to the pin. This thesis work is made within the partnership between Arts et Métiers ParisTech and Institut de Soudure. Its goal is to develop a FSW simulation model in order to decrease experimental trials required to optimize the process. Therefore, some points have been treated in this manuscript. Experimental analysis of thermal cycles and material movements in the case of unthreaded tools has been carried out. This situation allows (1) to make the comparison with numerical simulation easier and (2) to be in the case of worn tools. Formulations (lagrangian, eulerian, ALE) analysis in order to choose the more appropriate to take material flow into account has allowed to select an eulerian formulation (implemented in the FLUENT software) to estimate thermal and kinematical fields in the steady state. The set up of the numerical model in the FLUENT software is presented. We have studied the influence of numerical parameters on the results and proposed an identification strategy for some parameters which are not reachable experimentally. A detailed comparison between our experimental results and the ones from our simulations have been performed with success. The study of the influence of the process parameters (feed rate, rotating speed) and of the pin geometry on the kinematical and thermal fields has highlighted the link between velocity field and the presence of tunnel type defects
29
Hejl, Zdeněk. "Rekonstrukce 3D scény z obrazových dat". Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2012. http://www.nusl.cz/ntk/nusl-236495.
Testo completoAbstract (sommario):
This thesis describes methods of reconstruction of 3D scenes from photographs and videos using the Structure from motion approach. A new software capable of automatic reconstruction of point clouds and polygonal models from common images and videos was implemented based on these methods. The software uses variety of existing and custom solutions and clearly links them into one easily executable application. The reconstruction consists of feature point detection, pairwise matching, Bundle adjustment, stereoscopic algorithms and polygon model creation from point cloud using PCL library. Program is based on Bundler and PMVS. Poisson surface reconstruction algorithm, as well as simple triangulation and own reconstruction method based on plane segmentation were used for polygonal model creation.
30
Pitout, Cédric. "Conception et utilisation d'un système d'information géographique pour l'étude et le suivi de sites industriels pollués : Analyse spatiale 2D-3D. Analyse multiparamètre". Lille 1, 2000. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2000/50377-2000-23.pdf.
Testo completo
31
Buchholz, Bert. "Abstraction et traitement de masses de données 3D animées". Phd thesis, Télécom ParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00958339.
Testo completoAbstract (sommario):
Dans cette thèse, nous explorons des structures intermédiaires ainsi que le rapport entre eux et des algorithmes utilisés dans le contexte du rendu photoréaliste (RP) et non photoréaliste (RNP). Nous présentons des nouvelles structures pour le rendu et l'utilisation alternative des structures existantes. Nous présentons trois contributions principales dans les domaines RP et RNP: Nous montrons une méthode pour la génération des images stylisées noir et blanc. Notre approche est inspirée par des bandes dessinées, utilisant l'apparence et la géometrie dans une formulation d'énérgie basée sur un graphe 2D. En contrôlant les énérgies, l'utilisateur peut générer des images de differents styles et représentations. Dans le deuxième travail, nous proposons une nouvelle méthode pour la paramétrisation temporellement cohérente des lignes animées pour la texturisation. Nous introduisons une structure spatiotemporelle et une formulation d'énérgie permettant une paramétrisation globalement optimale. La formulation par une énérgie donne un contrôle important et simple sur le résultat. Finalement, nous présentons une extension sur une méthode de l'illumination globale (PBGI) utilisée dans la production de films au cours des dernières années. Notre extension effectue une compression par quantification de données générées par l'algorithme original. Le coût ni de memoire ni de temps excède considérablement celui de la méthode d'origin et permet ainsi le rendu des scènes plus grande. L'utilisateur a un contrôle facile du facteur et de la qualité de compression. Nous proposons un nombre d'extensions ainsi que des augmentations potentielles pour les méthodes présentées.
32
Attia, Youssef. "Interfaçage de bases de données photographiques et géographiques par appariement de lignes". Phd thesis, Université Jean Monnet - Saint-Etienne, 2012. http://tel.archives-ouvertes.fr/tel-00944135.
Testo completoAbstract (sommario):
Interfacer les photographies et les bases de données géographiques est une démarche utile pour les architectes, les historiens, les géographes mais aussi pour le grand public. Affecter une position géographique à une photographie permet en effet de décrire son contenu potentiel en s'appuyant sur les informations contenues dans une base de données géographique. L'objectif de la thèse est de proposer une méthode permettant de localiser automatiquement une photographie urbaine en la comparant avec des images de synthèse en 3D générées de manière systématique à partir d'un modèle virtuel des bâtiments. Le principe est que la photographie partage avec les images des caractéristiques géométriques qui permettent de les rapprocher et donc de déduire la localisation de la photographie à partir de la position connue de l'image. La méthode utilisée pour retrouver les images de synthèse correspondantes est un appariement entre les lignes présentes dans la photographie et les lignes détectées dans les images de synthèse par la transformation de Hough. Cet appariement est suivi par une analyse statistique permettant de proposer une localisation probable avec une valeur d'approximation associée.Malgré les obstacles présents dans les photographies, cette approche utilisant uniquement les lignes est une solution simple et potentiellement efficace pour le positionnement de photographies. Plusieurs scénarios d'usage sont proposés : la géolocalisation d'une image, la validation du positionnement d'une image localisée et l'utilisation de photographies pour repérer des changements dans le paysage urbain.
33
Fernandez, Julia Laura. "Avancements dans l'estimation de pose et la reconstruction 3D de scènes à 2 et 3 vues". Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1157/document.
Testo completoAbstract (sommario):
L'étude des caméras et des images a été un sujet prédominant depuis le début de la vision par ordinateur, l'un des principaux axes étant l'estimation de la pose et la reconstruction 3D. Le but de cette thèse est d'aborder et d'étudier certains problèmes et méthodes spécifiques du pipeline de la structure-from-motion afin d'améliorer la précision, de réaliser de vastes études pour comprendre les avantages et les inconvénients des modèles existants et de créer des outils mis à la disposition du public. Plus spécifiquement, nous concentrons notre attention sur les pairs stéréoscopiques et les triplets d'images et nous explorons certaines des méthodes et modèles capables de fournir une estimation de la pose et une reconstruction 3D de la scène.Tout d'abord, nous abordons la tâche d'estimation de la profondeur pour les pairs stéréoscopiques à l'aide de la correspondance de blocs. Cette approche suppose implicitement que tous les pixels du patch ont la même profondeur, ce qui produit l'artefact commun dénommé "foreground-fattening effect". Afin de trouver un support plus approprié, Yoon et Kweon ont introduit l'utilisation de poids basés sur la similarité des couleurs et la distance spatiale, analogues à ceux utilisés dans le filtre bilatéral. Nous présentons la théorie de cette méthode et l'implémentation que nous avons développée avec quelques améliorations. Nous discutons de quelques variantes de la méthode et analysons ses paramètres et ses performances.Deuxièmement, nous considérons l'ajout d'une troisième vue et étudions le tenseur trifocal, qui décrit les contraintes géométriques reliant les trois vues. Nous explorons les avantages offerts par cet opérateur dans la tâche d'estimation de pose d'un triplet de caméras par opposition au calcul des poses relatives paire par paire en utilisant la matrice fondamentale. De plus, nous présentons une étude et l’implémentation de plusieurs paramétrisations du tenseur. Nous montrons que l'amélioration initiale de la précision du tenseur trifocal n'est pas suffisante pour avoir un impact remarquable sur l'estimation de la pose après ajustement de faisceau et que l'utilisation de la matrice fondamentale avec des triplets d'image reste pertinente.Enfin, nous proposons d'utiliser un modèle de projection différent de celui de la caméra à sténopé pour l'estimation de la pose des caméras en perspective. Nous présentons une méthode basée sur la factorisation matricielle due à Tomasi et Kanade qui repose sur la projection orthographique. Cette méthode peut être utilisée dans des configurations où d'autres méthodes échouent, en particulier lorsque l'on utilise des caméras avec des objectifs à longue distance focale. La performance de notre implémentation de cette méthode est comparée à celle des méthodes basées sur la perspective, nous considérons que l'exactitude obtenue et la robustesse démontré en font un élément à considérer dans toute procédure de la SfMThe study of cameras and images has been a prominent subject since the beginning of computer vision, one of the main focus being the pose estimation and 3D reconstruction. The goal of this thesis is to tackle and study some specific problems and methods of the structure-from-motion pipeline in order to provide improvements in accuracy, broad studies to comprehend the advantages and disadvantages of the state-of-the-art models and useful implementations made available to the public. More specifically, we center our attention to stereo pairs and triplets of images and discuss some of the methods and models able to provide pose estimation and 3D reconstruction of the scene.First, we address the depth estimation task for stereo pairs using block-matching. This approach implicitly assumes that all pixels in the patch have the same depth producing the common artifact known as the ``foreground fattening effect''. In order to find a more appropriate support, Yoon and Kweon introduced the use of weights based on color similarity and spatial distance, analogous to those used in the bilateral filter. We present the theory of this method and the implementation we have developed with some improvements. We discuss some variants of the method and analyze its parameters and performance.Secondly, we consider the addition of a third view and study the trifocal tensor, which describes the geometric constraints linking the three views. We explore the advantages offered by this operator in the pose estimation task of a triplet of cameras as opposed to computing the relative poses pair by pair using the fundamental matrix. In addition, we present a study and implementation of several parameterizations of the tensor. We show that the initial improvement in accuracy of the trifocal tensor is not enough to have a remarkable impact on the pose estimation after bundle adjustment and that using the fundamental matrix with image triplets remains relevant.Finally, we propose using a different projection model than the pinhole camera for the pose estimation of perspective cameras. We present a method based on the matrix factorization due to Tomasi and Kanade that relies on the orthographic projection. This method can be used in configurations where other methods fail, in particular, when using cameras with long focal length lenses. The performance of our implementation of this method is compared to that given by the perspective-based methods, we consider that the accuracy achieved and its robustness make it worth considering in any SfM procedure
34
Guezzi, Messaoud Fadoua. "Analyse de l'apport des technologies d'intégration tri-dimensionnelles pour les imageurs CMOS : application aux imageurs à grande dynamique". Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1022/document.
Testo completoAbstract (sommario):
La poursuite de l'intégration de fonctions toujours plus complexes au sein d'un même circuit constitue un des principaux enjeux de la microélectronique. L'intégration tridimensionnelle par empilement de circuits (3D stacking) constitue une voie prometteuse pour y parvenir. Elle permet notamment de dépasser certaines limitations atteintes par les circuits actuels, plus particulièrement dans les circuits pour lesquelles les données sont distribuées et qui nécessitent des bandes passantes importantes. Néanmoins, à ce jour, très peu de travaux ont montré les avantages de l'intégration 3D, en particulier ceux s'appuyant sur des résultats expérimentaux et de circuits concrets notamment dans le domaine des imageurs. Le présent travail de thèse a eu pour objectif d'exploiter la technologie 3D dans le cadre des capteurs d'images et dépasser la preuve de concept présentée dans l'état de l'art afin d'apporter une analyse concrète des apports de cette technologie dans le domaine des imageurs visibles. Nous avons identifié, d'une part l'extension de dynamique qui requiert un traitement proche pixel, d'autre part la compression locale, destinée à adresser les problèmes d'intégrité du signal, bande passante et consommation qui deviennent critiques avec l'augmentation des formats des imageurs. Ce choix permet d'apporter une réponse à la limitation de la dynamique des capteurs d'images 2D actuels, tout en gardant une architecture classique des pixels et en adressant le problème de la réduction de la quantité de données à transmettre. Une nouvelle méthode de codage flottant par groupe de pixels a été proposée et implémentée. Le principe s'appuie sur l'adaptation du temps d'intégration par groupe de pixels via l'application d'un exposant commun au groupe. Le temps d'intégration est ajusté à l'image suivante. Un premier niveau de compression est ainsi réalisé par le codage mantisse-exposant proposé. L'implémentation de cette technique a été validée sur un démonstrateur 2D au détriment de pixels sacrifiés aveugles de chaque groupe de pixels, comportant l'électronique de génération des signaux de commande de la HDR. La technique d'extension de dynamique proposée est suivie d'une compression à base de DCT (Discrete Cosine Transform} permettant de réduire le flux de données en sortie de la puce imageur. Les deux niveaux de compression permettent d'atteindre des taux de compression élevés allant jusqu'à 93% en maintenant un PSNR de 30dB et une qualité d'image acceptable pour des post-traitements. Une étude théorique de l'apport de l'intégration 3D en termes de consommation a été élaborée. Enfin, un démonstrateur 2D a été réalisé en technologie CMOS 180 nm en vue de valider l'architecture grande dynamique proposée. L'utilisation de la technologie 3D, dans la suite des travaux, permet l'implémentation d'une boucle courte, devenue possible grâce aux interconnexions verticales sans sacrifier des pixels morts. Le traitement local proche du pixel et la réduction de la latence, du flux de données et de la consommation sont les apports majeurs de l'intégration 3D étudiés dans ce travailWith the increase of systems complexity, integrating different technologies together has become a major challenge. Another challenge has traditionally been the limitation on the throughout between different part of the system coming from the interconnections. If traditional two dimensional integration solutions like System In a Package (SIP) bring heterogonous technologies together there is still limitations coming from the restricted number and lengths of interconnections between the different system components. Three Dimensional stacking (3D), by exploiting short vertical interconnections between different circuits of mixed technologies, has the potential to overcome these limitations. Still, despite strong interests for the 3D concepts, there is no advanced analysis of 3D integration benefits, especially in the field of imagers and smart image sensors. This thesis study the potential benefits of 3D integration, with local processing and short feedback loops, for the realisation of a High Dynamic Range (HDR) image sensor. The dense vertical interconnections are used to locally adapt the integration time by group of pixels, called macro-pixels, while keeping a classic pixel architecture and hence a high fill factor. Stacking the pixel section and circuit section enables a compact pixel and the integration of flexible and versatile functions. High Dynamic Range values producing an important quantity of data, the choice has been made to implement data compression to reduce the circuit throughout. A first level of compression is produced by coding the pixel value using a floating format with a common exponent shared among the macro-pixel. A second level of compression is proposed based on a simplified version of the Discrete Cosine Transform (DCT). Using this two level scheme, a compression of 93% can be obtained with a typical PSNR of 30 dB. A validation of the architecture was carried out by the development; fabrication and test of a prototype on a 2D, 180 nm, CMOS technology. A few pixels of each macro-pixel had to be sacrificed to implement the high dynamic range control signals and emulate the 3D integration. The test results are very promising proving the benefits that will bring the 3D integration in term of power consumption and image quality compared to a classic 2D integration. Future realisations of this architecture, done using a real 3D technology, separating sensing and processing on different circuits communicating by vertical interconnection will not need the sacrifice of any pixel to adjust the integration time, improving power consumption, image quality and latency
35
Batmaz, Anil Ufuk. "Speed, precision and grip force analysis of human manual operations with and without direct visual input". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ056/document.
Testo completoAbstract (sommario):
Le système perceptif d’un chirurgien doit s’adapter aux contraintes multisensorielles liées à la chirurgie guidée par l’image. Trois expériences sont conçues pour explorer ces contraintes visuelles et haptiques pour l’apprentissage guidé par l’image. Les résultats montrent que les sujets sont plus rapides et plus précis avec une vision directe. La stéréoscopie 3D n’améliore pas les performances des débutants complets. En réalité virtuelle, la variation de la longueur, largeur, position et complexité de l'objet affecte les performances motrices. La force de préhension appliquée sur un système robotique chirurgical dépend de l'expérience de l'utilisateur. En conclusion, le temps et la précision sont importants, mais la précision doit rester une priorité pour un apprenti. L'homogénéité des groupes d'étude est important pour la recherche sur la formation chirurgicale. Les résultats ont un impact direct sur le suivi des compétences individuelles pour les applications guidées par l'imagePerceptual system of a surgeon must adapt to conditions of multisensorial constrains regard to planning, control, and execution of the image-guided surgical operations. Three experimental setups are designed to explore these visual and haptic constraints in the image-guided training. Results show that subjects are faster and more precise with direct vision compared to image guidance. Stereoscopic 3D viewing does not represent a performance advantage for complete beginners. In virtual reality, variation in object length, width, position, and complexity affect the motor performance. Applied grip force on a surgical robot system depends on the user experience level. In conclusion, both time and precision matter critically, but trainee gets as precise as possible before getting faster should be a priority. Study group homogeneity and background play key role in surgical training research. The findings have direct implications for individual skill monitoring for image-guided applications
36
Ting, Yu-Hisn, e 丁友信. "3D Imaging based on Integral Photography Technology". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/81689620600188640454.
Testo completoAbstract (sommario):
碩士長庚大學
半導體科技研究所
91
Integral photography (IP) can be regarded as a method of capturing and displaying light rays passing through a plane. Because a three-dimensional (3-D) autostereoscopic image can be seen from a designed viewpoint without any special viewing glasses, IP is an ideal method to create 3-D autostereoscopic images. The conventional IP method in which is placed the film or a CCD camera behind a lens array immediately. In this thesis, the author proposes a method of analyzing maximum resolution and viewing angle from IP images simulated by the ASAP software, which enables us to getting optimum reconstruction image quality. Final simulated results show the potential to build the whole IP optical system by computer simulation technologies.
37
Jirathamopas, Jinwara, e 曾玲玲. "Female facial attractiveness Assessed by 2D Photography and 3D Face-scan". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/56485205244003294403.
Testo completoAbstract (sommario):
碩士長庚大學
顱顏口腔醫學研究所
102
Background: This is a serial study 1) to evaluate the consistency of female facial attractive perception across gender, age and professional background and 2) to present whether contour lines could be used to evaluate facial attractiveness. Materials and methods: Series of 100 female 2D photos (one frontal, two lateral views) were projected on a screen. Each photo lasted 5 seconds and raters marked their impression of facial attractiveness on a 5-point Likert scale within 3 seconds. Raters included hospital staffs and laypeople. The consistency of facial attractive perception was compared between raters according to gender, age, and professional background. Same protocol was carried out with 100 contour line images extracted from 3D images of the same samples. The evaluation was performed twice in 2 weeks apart. Raters were laypeople only. The consistency of facial contour lines perception and the correlation between mean facial attractive scores of 2D photos and contour lines were calculated. Results: High consistency was found for all of the comparisons. In the evaluation of 2D photos, females give higher score than males and the significant different was found among laypeople (p=0.011). No significant different between the rating of senior and junior raters (p=0.457 and 0.781 for hospital staffs and laypeople). Hospital staffs rated significant higher score than laypeople (p=0.005). In the evaluation of contour lines, females give higher score than males and significant different was found in 2nd time rating (p=0.017). The correlation between contour lines and attractiveness was r = 0.576 and 0.574 for 1st and 2nd time evaluation. Conclusion: The perception of 2D or contour line female facial attractiveness was very consistent. Only gender and professional background influence female attractive perception. The correlation between facial attractiveness and contour lines were moderate.
38
Hasinoff, Samuel William. "Variable-aperture Photography". Thesis, 2008. http://hdl.handle.net/1807/16734.
Testo completoAbstract (sommario):
While modern digital cameras incorporate sophisticated engineering, in terms of their core functionality, cameras have changed remarkably little in more than a hundred years. In particular, from a given viewpoint, conventional photography essentially remains limited to manipulating a basic set of controls: exposure time, focus setting, and aperture setting.
In this dissertation we present three new methods in this domain, each based on capturing multiple photos with different camera settings. In each case, we show how defocus can be exploited to achieve different goals, extending what is possible with conventional photography. These methods are closely connected, in that all rely on analyzing changes in aperture.
First, we present a 3D reconstruction method especially suited for scenes with high geometric complexity, for which obtaining a detailed model is difficult using previous approaches. We show that by controlling both the focus and aperture setting, it is possible compute depth for each pixel independently. To achieve this, we introduce the "confocal constancy" property, which states that as aperture setting varies, the pixel intensity of an in-focus scene point will vary in a scene-independent way that can be predicted by prior calibration.
Second, we describe a method for synthesizing photos with adjusted camera settings in post-capture, to achieve changes in exposure, focus setting, etc. from very few input photos. To do this, we capture photos with varying aperture and other settings fixed, then recover the underlying scene representation best reproducing the input. The key to the approach is our layered formulation, which handles occlusion effects but is tractable to invert. This method works with the built-in "aperture bracketing" mode found on most digital cameras.
Finally, we develop a "light-efficient" method for capturing an in-focus photograph in the shortest time, or with the highest quality for a given time budget. While the standard approach involves reducing the aperture until the desired region is in-focus, we show that by "spanning" the region with multiple large-aperture photos,we can reduce the total capture time and generate the in-focus photo synthetically. Beyond more efficient capture, our method provides 3D shape at no additional cost.
39
Weng, Chia-Duo, e 翁家鐸. "Application of VR object Photography in on-line displaying of 3D products". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/65684546498189632756.
Testo completoAbstract (sommario):
碩士國立臺北教育大學
文化創意產業經營學系
99
Image-based object movies are available for immediate interaction with the virtual three-dimensional characteristics of real images, to convey a more complete three-dimensional objects in rich visual image information, has been regarded as an important heritage records and show good results. This study used relative approaches documents, marketing theory, implementation, verification, and comprehensive expert interviews , and tried to explore the development of online three-dimensional display of goods . The results showed that the display of effect and application development object movie were well received and very useful for online shopping, especially for higher priced fine display. However, the speed of network bandwidth to be able to immediately meet the production costs and convenience, there is hope for improvement.
40
Wang, Jia-Hong, e 翁嘉鴻. "Achieving Floating 3D Image with Applying Integral Photography Theory in Oblique Viewing Angle". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/19481816671249812222.
Testo completoAbstract (sommario):
碩士國立交通大學
光電工程研究所
103
With the rapid growth of the three-dimensional (3D) stereoscopic image technology, the various application and potential has become more and more important in our modern life. However, comparing with the “pop out” 3D image in the direct viewing angle presented by the flat panel display and movie, the fantastic “floating” 3D image which allows people to perceive and interact with in the sci-fi movie is more and more attractive. Therefore, the floating 3D image is undoubtedly the brand new landmark of the display technology in the next generation. To achieve the target, 3D image in oblique viewing angle, in other words, the floating 3D image is the essential technology. Nevertheless in nowadays, floating image confronts the issues on the inconvenience feature, limitation of application and the volumetric characteristic. The technology is not mature enough for the user-friendly requirement. Hence, we apply a simple concept to achieve the floating 3D image and expect the concept could be applied on various structures, including projector and mobile device. The concept is integral photography (IP) theory in oblique viewing angle. Different with the disparity method of modern 3D technology, which gives different views to our left and right eye to form the 3D image, IP theory reconstructs the light field, showing true 3D image without causing visual fatigue. Among our research, the effect and issue of projection type and display type integral image (InI) in oblique viewing angle with applying micro lens array and pinhole array are discussed in detail. Moreover, a human factor experiment is done. The different factors such as floating height and viewing angle that may influence the image quality of the floating InI are also carefully analyzed. The research applies IP theorem on projector and mobile device, achieving good floating 3D image with simple structure and convenient adjustment and showing various applications and freedom for this concept. Furthermore, the true 3D image with light field reconstruction could satisfy the interaction requirement; the rapid calculation with computational algorithm could draft the image content without the capture stage, enhancing the freedom of the displaying image and also showing the potential for discussion with many kinds of factors in the future. The research would lead us step by step to the fantastic and charming world of floating 3D image technology.
41
Fiveash, Tina Dale Media Arts College of Fine Arts UNSW. "The enigma of appearances: photography of the third dimension". 2007. http://handle.unsw.edu.au/1959.4/44259.
Testo completoAbstract (sommario):
The Enigma of Appearances is an examination into the medium of three-dimensional photography, with particular focus on the technique of stereoscopy. Invented in the mid-Victorian era, stereoscopy was an attempt to simulate natural three-dimensional perception via a combination of optics, neurology, and a pair of dissimilar images. Whilst successful in producing a powerful illusion of spatial depth and tangibility, the illusion produced by stereoscopy is anything but ??natural??, when compared to three-dimensional perception observed with the naked eye. Rather, stereoscopic photography creates a strange and unnatural interpretation of three-dimensional reality, devoid of atmosphere, movement and sound, where figures appear frozen in mid-motion, like waxwork models, or embalmed creatures in a museum. However, it is precisely stereoscopic photography??s unique and enigmatic interpretation of three-dimensional reality, which gives it its strength, separating it from being a mere ??realistic?? recording of the natural world. This thesis examines the unique cultural position that stereoscopy has occupied since its invention in 1838, from its early role as a tool for the study of binocular vision, to its phenomenal popularity as a form of mass entertainment in the second half of the 19th century, to its emergence in contemporary fine art practice in the late 20th and 21stt centuries. Additionally, The Enigma of Appearances gives a detailed analysis of the theory of spatial depth perception; it discusses the dichotomy between naturalia versus artificialia in relation to stereoscopic vision; and finally, traces the development of experimental studio practice and research into stereoscopic photography, undertaken for this MFA between 2005 and 2007. The resulting work, Camera Mortuaria (Italian for ??Mortuary Room??), is a powerful and innovative series of anaglyptic portraits, based upon an experimental stereoscopic technique that enables the production of extreme close-up three-dimensional photography. Applying this technique to the reproduction of the human face in three-dimensional form, Camera Mortuaria presents a series of ??photo sculptures??, which hover between reality and illusion, pushing the boundaries of stills photography to the limit, and beyond.
42
Almeida, Vítor Miguel Amorim de. "3D reconstruction through photographs". Master's thesis, 2014. http://hdl.handle.net/10400.13/1057.
Testo completoAbstract (sommario):
Humans can perceive three dimension, our world is three dimensional and it is becoming increasingly digital too. We have the need to capture and preserve our existence in digital means perhaps due to our own mortality.
We have also the need to reproduce objects or create small identical objects to prototype, test or study them. Some objects have been lost through time and are only accessible through old photographs.
With robust model generation from photographs we can use one of the biggest human data sets and reproduce real world objects digitally and physically with printers.
What is the current state of development in three dimensional reconstruction through photographs both in the commercial world and in the open source world? And what tools are available for a developer to build his own reconstruction software? To answer these questions several pieces of software were tested, from full commercial software packages to open source small projects, including libraries aimed at computer vision.
To bring to the real world the 3D models a 3D printer was built, tested and analyzed, its problems and weaknesses evaluated. Lastly using a computer vision library a small software with limited capabilities was developed.
43
Wang, Yu-Chi, e 王煜智. "Reconstructing 3D Model of Real Scenes from Photographs". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/10929116439838702092.
Testo completoAbstract (sommario):
碩士國立成功大學
電腦與通信工程研究所
93
In this paper, we present a system which automatically extracts the 3D information and reconstructs a textured 3D model from a sequence of images of a real scene. No prior knowledge about the scene is needed to build the 3D models. All information such as camera pose and orientation will be estimated through the processes. Therefore, this system offers a high degree of flexibility when taking photographs. The only constraint is that the intrinsic camera parameters need to be obtained first. The 3D modeling task is decomposed into 4 successive steps. The camera intrinsic parameters are calibrated using a calibration board first. Second, the camera pose and the epipolar geometry between a stereoscopic image pair are estimated by the corresponding points of this pair. Next, consecutive images of the sequence are treated as stereo pair and the disparity maps are computed by area matching. Finally, the dense 3D points are estimated by the linking matches through consecutive image pairs. Then, these 3D points are visualized as a 3D model which is also texture mapped for photo-realistic appearance. This system has been tested on several real scenes, and some of the reconstructed models are shown in this paper.
44
Wu, Sara, e 吳宜樺. "To construct 3D human model from 2D photograph". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/76995668107455197224.
Testo completo
45
Millar, Usiskin Josh. "4D reconstruction of construction photographs". 2013. http://hdl.handle.net/1993/22057.
Testo completoAbstract (sommario):
Recent research has enabled reconstruction of a scene from multiple images. These algorithms rely on assumptions that the scene does not change drastically from one photo to the next. Construction photographs, in particular, pose challenges for the existing algorithms. I propose a novel image-based reconstruction algorithm that overcomes these limitations and reconstructs a 4D indoor Manhattan model using construction photographs. Finally, I present a novel user interface that combines image-based rendering and intuitive 4D navigation controls to observe and explore the resulting reconstruction.
46
Abson, Karl, Hassan Ugail e Stanley S. Ipson. "A methodology for feature based 3D face modelling from photographs". 2008. http://hdl.handle.net/10454/2435.
Testo completoAbstract (sommario):
In this paper, a new approach to modelling 3D faces based on 2D images is introduced. Here 3D faces are created using two photographs from which we extract facial features based on image manipulation techniques. Through the image manipulation techniques we extract the crucial feature lines of the face in two views. These are then used in modifying a template base mesh which is created in 3D. This base mesh, which has been designed by keeping facial animation in mind, is then subdivided to provide the level of detail required. The methodology, as it stands, is semi-automatic whereby our goal is to automate this process in order to provide an inexpensive and expedient way of producing realistic face models intended for animation purposes. Thus, we show how image manipulation techniques can be used to create binary images which can in turn be used in manipulating a base mesh that can be adapted to a given facial geometry. In order to explain our approach more clearly we discuss a series of examples where we create 3D facial geometry of individuals given the corresponding image data.
47
Hsu, Lung-kai, e 徐瓏愷. "The Research and Creation of 3D Stereoscopic Animation Applying Stereoscopic Display －"The Photographer"". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/06049405591227833971.
Testo completoAbstract (sommario):
碩士國立雲林科技大學
設計運算研究所碩士班
100
Since 2010, the display technology has become the mainstream technology and meanwhile many other stereoscopic effect technologies have come along with this trend. However, one problem has emerged, that is the output of the digital content is way slower than the development of the new hardware. As a result, this 3D computer animation work is trying to apply the Stereoscopic Display by using the Shutter Glasses System as the basic hardware in order to further create and present this 3D effect animation short film – The Photographer. I use this film to analyze and record all the problems that happened regarding to the 3D display technology during my working process. The result showed that when making a 3D animation, it is not only about the settings of two cameras. Instead, it concerned with stereology and the analyses of every statistics which were strongly related to the physical feelings of the audiences and it was something that all the 3D animators should be aware of. After completing the film, the creator found that the planning of the whole working process mattered the most in terms of making the stereoscopic animation since it was more complicated and time-consuming than the normal films. Hence, while making the film, the creator tried to build a standard operating procedure regarding the creation of stereoscopic animation for future references.
48
Ciou, Jian-Wei, e 邱健瑋. "The Application of 3D Reconstruction and Measurement Based on Single Image of Oblique Photograph by UAV". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/an3c94.
Testo completoAbstract (sommario):
碩士國立高雄應用科技大學
土木工程與防災科技研究所
104
It is not easy to measure statistics on images through traditional photography in the early period, it is even unable to measure the figures from images, resulted in overbank. Thus, there is no further description about oblique photograph. Nevertheless, since MVS( Multi View Stereo) 3D reconstruction starts being applied, it loosens the aviation requirements of UAV. Combining the digital compact camera with UAV( Unmanned Aerial Vehicles) to shooting, it can not only reduce the shooting cost, but the resolution and stability are much higher than aero photography by comparison.Therefore the study includes camera calibration, 3D reconstruction, generats the true Orthophoto based on morden view stereo processing. Before camera self-calibration begin to develop, people use pre-calibration to solve the intrinsic parameters and exterior orientation parameters, pre-calibration could get the steady answer, but the requirements are complex and time-consuming. The development of self-calibration improve the problems of pre-calibration, however, the requirements of self-calibration is unstable, so there are accuracy analysis of the camera self-calibration, therefore, to compare with the applicability of camera calibration methods, the experiment select region of National Kaohsiung University of Applied Sciences and choose different numbers of control points to explore the results of the calibration. Today commercial Oblique Photograph processing system and 3D reconstruction are using traditional photogrammetric aerial triangulation method by the perfectional camera with high resolution but it is also expensive, so this study design uses digital camera by unmanned aerial vehicle to shoot and use modern methods of stereo vision SfM reconstruction, mainly discusses tilt integrity model photography and 3D reconstructio accuracy, and provide DEM let measurement based on single image of oblique photograph to use.The experiment selects National Kaohsiung University of Applied Sciences and Taichung city to do reconstruction and explore completion and accuracy of 3D reconstruction model. In order to make the images apply fleetly, this research utilize collinearity principle to measure single image of oblique photograph, mainly because the lateral information of tilted images are rich, and it can fully display the characteristics and construction of the object. The experiment selects a region of National Kaohsiung University of Applied Sciences to compare the difference of dense cloud, measurement based on single image and survey. The part of the camera calibration show there is no significant difference between the two methods, self-calibration even better than pre-calibration. From the experiment of 3D-reconstruction show because of a lot of observation, accuracy of oblique photography method is better than traditional photography, even get complete model. Measurement of Single image gets 3D information quickly and have less than 2 pixel difference, therefore, through direct measurement method can provide images for disaster response or after a field survey reference.
49
Chu, Te-Yuen, e 朱德原. "The application of terrestrial 3D Laser Scanner and Aerial Photographs to investigate the sea cliff changes over the last decade at Chi Lai Bi, Hualien". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/55773142122810733378.
Testo completoAbstract (sommario):
碩士國立花蓮教育大學
地球科學研究所
96
Abstract Chi-Lai-Bi sea cliff is a natural sea cliff without any hard engineering protection from the erosion of waves. This study uses aerial photographs (on October 13, 1993, April 15, 2002 and September 5, 2002 respectively) and digital photographs (on June 27, 2005 and September 5, 2006 respectively) to establish 5 different stages of 2 meters Digital Surface Model (DSM) of Chi-Lai-Bi sea cliff, Hualien and the surrounding area in order to investigate a middle-term topographic change of the sea cliff. For a short-term topographic change of the sea cliff, using terrestrial 3D laser scanner (on July 3, August 30 and November 16, 2007 respectively) reconstructs 3 different stages of 10 centimeters DSM of Chi Lai Bi sea cliff, Hualien. Moreover, a Light Detection And Ranging (LiDAR) result from the 9th River Management Bureau on July 5, 2005 is also used to create a Digital Terrain Model (DTM) of Chi-Hsing-Tan area and of Chi-Lai-Bi sea cliff in order to compare the short-term sea cliff change. The result of the middle-term sea cliff change shows: (1) The shorter time span of sea cliff change is faster than longer time span of the sea cliff change. For example, from June, 2005 to September, 2006 the average recession of the sea cliff is 1.62 meters, but from October, 1993 to April, 2002 the annual mean recession of the sea cliff is 1.25 meters and from October, 1993 to September, 2006 the annual mean recession of the sea cliff is 1.3 meters respectively. (2) The Chi Lai Bi sea cliff has both the erosions and accumulations areas, the erosion areas are mainly caused by ocean waves and Typhoon in the sea cliff margin, the accumulation areas are created by human interference such as in a land filled site and the storage of stone materials in a nearby open space. The result of the short-term sea cliff change using terrestrial 3D laser scanner and the LiDAR data shows:(1) The study area of 10520 square meters has a 5600 cubic meters volume reduction and an average of 0.53 m height reduction between July 3, 2007 and November 16, 2007 during the Typhoon season. (2) Ten west-east profiles of the sea cliff DSM from north to south show two different types of erosion trend, the first type is that 5 meter above the sea surface, the sea cliff has been eroded and the eroded materials are then either accumulated at the foot of the sea cliff or moved by the waves, the second type is that the sea cliff has no obvious change. (3) Comparing the sea cliff change using LiDAR and the latest terrestrial 3D laser scanner data shows, the sea cliff change has the similar pattern as using terrestrial 3D laser scanner data only.
50
Egoda, Gamage Ruwan Janapriya. "A high resolution 3D and color image acquisition system for long and shallow impressions in crime scenes". Thesis, 2014. http://hdl.handle.net/1805/5906.
Testo completoAbstract (sommario):
Indiana University-Purdue University Indianapolis (IUPUI)In crime scene investigations it is necessary to capture images of impression evidence such as tire track or shoe impressions. Currently, such evidence is captured by taking two-dimensional (2D) color photographs or making a physical cast of the impression in order to capture the three-dimensional (3D) structure of the information. This project aims to build a digitizing device that scans the impression evidence and generates (i) a high resolution three-dimensional (3D) surface image, and (ii) a co-registered two-dimensional (2D) color image. The method is based on active structured lighting methods in order to extract 3D shape information of a surface. A prototype device was built that uses an assembly of two line laser lights and a high-definition video camera that is moved at a precisely controlled and constant speed along a mechanical actuator rail in order to scan the evidence. A prototype software was also developed which implements the image processing, calibration, and surface depth calculations. The methods developed in this project for extracting the digitized 3D surface shape and 2D color images include (i) a self-contained calibration method that eliminates the need for pre-calibration of the device; (ii) the use of two colored line laser lights projected from two different angles to eliminate problems due to occlusions; and (iii) the extraction of high resolution color image of the impression evidence with minimal distortion.The system results in sub-millimeter accuracy in the depth image and a high resolution color image that is registered with the depth image. The system is particularly suitable for high quality images of long tire track impressions without the need for stitching multiple images.