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Dissertations / Theses on the topic 'Image reconstruction. Three-dimensional imaging. Computer vision'
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1
Mai, Fei, and 買斐. "3D reconstruction of lines, ellipses and curves from multiple images." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40887911.
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Mai, Fei. "3D reconstruction of lines, ellipses and curves from multiple images." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40887911.
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Liu, Chi Hin. "Structured lighting 3D reconstruction and 3D shape matching of human model for garment industries /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20LIUC.
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Zhang, Xiongbo, and 張雄波. "3D trajectory recovery in spatial and time domains from multiple images." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/195966.
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Recovering 3D structure from multiple 2D images is a fundamental problem in computer vision. Most of existing methods focus on the reconstruction of static points in 3D space; however, the reconstruction of trajectories which are resulted from moving points should also have our full attention due to its high efficiency in structure modeling and description. Depending on whether points are moving in spatial domain or in time domain, trajectory recovery turns out to be a curve reconstruction problem or a non-rigid structure recovery problem respectively. This thesis addresses several issues that were not considered in existing approaches in both of the two problems.
For the curve reconstruction problem, we propose a dedicated method for planar curve reconstruction and an optimization method for general curve reconstruction. In the planar curve reconstruction method, measured projected curves that are typically represented by sequences of points are fitted using B-splines before reconstruction, enabling the occlusion problem to be handled naturally. Also, an optimization algorithm is developed to match the fitted curves across images while enforcing the planarity constraint, and the algorithm is guaranteed to converge. In the general curve reconstruction method, Non-Uniform Rational B-Spline (NURBS) is employed for curve representation in 3D space, which improves the flexibility in curve description while maintaining the smoothness of a curve at the same time. Starting with measured point sequences of projected curves, a complete set of algorithms are developed and evaluated, including curve initialization and optimization of the initialized curve by minimizing the 2D reprojection error that is defined to be the 2D Euclidean distance from measured points to reprojected curves. Experiments show that the proposed methods are robust and efficient, and are excellent in producing high-quality reconstruction results.
For the non-rigid structure recovery problem, we proposed two methods for the recovery of non-rigid structures together with a strategy that automates the process of non-rigid structure recovery. Compared with existing methods using synthetic datasets, both of the two proposed methods perform significantly better than existing methods when there are noise contaminations in measurements, and are capable to recover the ground truth solution when the measurements are noise free whereas no existing method is capable of achieving this so far. In the first method, namely factorization-based method, the available constraints in non-rigid structure from motion are analyzed and the ambiguity of the solution space of the proposed method is clarified, leading to a straightforward approach that requires only solution to several linear equations in least-squares sense instead of having to solve non-linear optimization problems in existing methods. In the second method, namely bundle adjustment method, a modified trajectory basis model that is demonstrated to be more flexible for non-rigid structure description is proposed. The method seeks for optimal non-rigid structure and camera matrices by alternately solving a set of linear equations in least square sense. Experiments on real non-rigid motions show that the method improves the quality of reconstruction significantly.published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
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Kalghatgi, Roshan Satish. "Reconstruction techniques for fixed 3-D lines and fixed 3-D points using the relative pose of one or two cameras." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43590.
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In general, stereovision can be defined as a two part problem. The first is the correspondence problem. This involves determining the image point in each image of a set of images that correspond to the same physical point P. We will call this set of image points, N. The second problem is the reconstruction problem. Once a set of image points, N, that correspond to point P has been determined, N is then used to extract three dimensional information about point P.
This master's thesis presents three novel solutions to the reconstruction problem. Two of the techniques presented are for detecting the location of a 3-D point and one for detecting a line expressed in a three dimensional coordinate system. These techniques are tested and validated using a unique 3-D finger detection algorithm. The techniques presented are unique because of their simplicity and because they do not require the cameras to be placed in specific locations, orientations or have specific alignments. On the contrary, it will be shown that the techniques presented in this thesis allow the two cameras used to assume almost any relative pose provided that the object of interest is within their field of view.
The relative pose of the cameras at a given instant in time, along with basic equations from the perspective image model are used to form a system of equations that when solved, reveal the 3-D coordinates of a particular fixed point of interest or the three dimensional equation of a fixed line of interest. Finally, it will be shown that a single moving camera can successfully perform the same line and point detection accomplished by two cameras by altering the pose of the camera.
The results presented in this work are beneficial to any typical stereovision application because of the computational ease in comparison to other point and line reconstruction techniques. But more importantly, this work allows for a single moving camera to perceive three-dimensional position information, which effectively removes the two camera constraint for a stereo vision system. When used with other monocular cues such as texture or color, the work presented in this thesis could be as accurate as binocular stereo vision at interpreting three dimensional information. Thus, this work could potentially increase the three dimensional perception of a robot that normally uses one camera, such as an eye-in-hand robot or a snake like robot.
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Ganapathi, Annadurai Kartick. "3D Shape Reconstruction from Multiple Range Image Views." The University of Waikato, 2006. http://hdl.handle.net/10289/2267.
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Shape reconstruction of different three dimensional objects using multiple range images has evolved recently within the recent past. In this research shape reconstruction of a three dimensional object using multiple range image views is investigated. Range images were captured using the Waikato Range Imager. This range images camera is novel in that it uses heterodyne imaging and is capable of acquiring range images with precision less than a millimeter simultaneously over a full field. Multiple views of small objects were taken and the FastRBF was explored as a mean of registration and surface rendering. For comparison to the real range data, simulated range data under noise free condition were also generated and reconstructed with the FastRBF tool box. The registration and reconstruction of simple object was performed using different views with the FastRBF toolbox. Analysis of the registration process showed that the translation error produced due to distortion during registration of different views hinders the process of reconstructing a complete surface. While analyzing the shape reconstruction using the FastRBF tool it is also determined that a small change in accuracy values can affect the interpolation drastically. Results of reconstruction of a real 3D object from multiple views are shown.
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Steedly, Drew. "Rigid Partitioning Techniques for Efficiently Generating 3D Reconstructions from Images." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4925.
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This thesis explores efficient techniques for generating 3D reconstructions from imagery. Non-linear optimization is one of the core techniques used when computing a reconstruction and is a computational bottleneck for large sets of images. Since non-linear optimization requires a good initialization to avoid getting stuck in local minima, robust systems for generating reconstructions from images build up the reconstruction incrementally. A hierarchical approach is to split up the images into small subsets, reconstruct each subset independently and then hierarchically merge the subsets. Rigidly locking together portions of the reconstructions reduces the number of parameters needed to represent them when merging, thereby lowering the computational cost of the optimization.
We present two techniques that involve optimizing with parts of the reconstruction rigidly locked together. In the first, we start by rigidly grouping the cameras and scene features from each of the reconstructions being merged into separate groups. Cameras and scene features are then incrementally unlocked and optimized until the reconstruction is close to the minimum energy. This technique is most effective when the influence of the new measurements is restricted to a small set of parameters.
Measurements that stitch together weakly coupled portions of the reconstruction, though, tend to cause deformations in the low error modes of the reconstruction and cannot be efficiently incorporated with the previous technique. To address this, we present a spectral technique for clustering the tightly coupled portions of a reconstruction into rigid groups. Reconstructions partitioned in this manner can closely mimic the poorly conditioned, low error modes, and therefore efficiently incorporate measurements that stitch together weakly coupled portions of the reconstruction. We explain how this technique can be used to scalably and efficiently generate reconstructions from large sets of images.
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Schindler, Grant. "Unlocking the urban photographic record through 4D scene modeling." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34719.
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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.
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Wan, Sau Kuen. "Modeling with panoramic image network for image-based walkthroughs /." access full-text access abstract and table of contents, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?mphil-cs-b1988588xa.pdf.
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Thesis (M.Phil.)--City University of Hong Kong, 2005."Submitted to Department of Computer Science in partial fulfillment of the requirements for the degree of Master of Philosophy" Includes bibliographical references (leaves 81-84)
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Liang, Chen. "3D model reconstruction from silhouettes." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/b40203311.
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Liang, Chen, and 梁晨. "3D model reconstruction from silhouettes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40203311.
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McIlroy, Paul Malcolm. "Texture ambiguity and occlusion in live 3D reconstruction." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608119.
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Chen, Yu. "Probabilistic frameworks for single view reconstruction using shape priors." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610217.
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Tsang, Kin Ting. "Interactive 3D model reconstruction from images and quasi-dense points /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?COMP%202004%20TSANG.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 59-62). Also available in electronic version. Access restricted to campus users.
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Feng, Chunlin, and 馮淳林. "Robust estimation methods for image matching." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B29752693.
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Li, Yin. "Rendering driven image based modeling /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?COMP%202004%20LI.
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Fulton, John R. "Sensor orientation in image sequence analysis /." Connect to thesis, 2007. http://eprints.unimelb.edu.au/archive/00003510.
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Nain, Delphine. "Scale-based decomposable shape representations for medical image segmentation and shape analysis." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11192006-184858/.
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Thesis (Ph. D.)--Computing, Georgia Institute of Technology, 2007.Aaron Bobick, Committee Chair ; Allen Tannenbaum, Committee Co-Chair ; Greg Turk, Committee Member ; Steven Haker, Committee Member ; W. Eric. L. Grimson, Committee Member.
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Chen, Li. "λ-connectedness and its application to image segmentation, recognition and reconstruction." Thesis, University of Bedfordshire, 2001. http://hdl.handle.net/10547/268652.
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Seismic layer segmentation, oil-gas boundary surfaces recognition, and 3D volume data reconstruction are three important tasks in three-dimensional seismic image processing. Geophysical and geological parameters and properties have been known to exhibit progressive changes in a layer. However, there are also times when sudden changes can occur between two layers. λ-connectedness was proposed to describe such a phenomenon. Based on graph theory, λ-connectedness describes the relationship among pixels in an image. It is proved that λ-connectedness is an equivalence relation. That is, it can be used to partition an image into different classes and hence can be used to perform image segmentation. Using the random graph theory and λ-connectivity of the image, the length of the path in a λ-connected set can be estimated. In addition to this, the normal λ-connected subsets preserve every path that is λ-connected in the subsets. An O(nlogn) time algorithm is designed for the normal λ-connected segmentation. Techniques developed are used to find objects in 2D/3D seismic images. Finding the interface between two layers or finding the boundary surfaces of an oil-gas reserve is often asked. This is equivalent to finding out whether a λ-connected set is an interface or surface. The problem that is raised is how to recognize a surface in digital spaces. λ-connectedness is a natural and intuitive way for describing digital surfaces and digital manifolds. Fast algorithms are designed to recognize whether an arbitrary set is a digital surface. Furthermore, the classification theorem of simple surface points is deduced: there are only six classes of simple surface points in 3D digital spaces. Our definition has been proved to be equivalent to Morgenthaler-Rosenfeld's definition of digital surfaces in direct adjacency. Reconstruction of a surface and data volume is important to the seismic data processing. Given a set of guiding pixels, the problem of generating a λ-connected (subset of image) surface is an inverted problem of λ-connected segmentation. In order to simplify the fitting algorithm, gradual variation, an equivalent concept of λ-connectedness, is used to preserve the continuity of the fitted surface. The key theorem, the necessary and sufficient condition for the gradually varied interpolation, has been mathematically proven. A random gradually varied surface fitting is designed, and other theoretical aspects are investigated. The concepts are used to successfully reconstruct 3D seismic real data volumes. This thesis proposes λ-connectedness and its applications as applied to seismic data processing. It is used for other problems such as ionogram scaling and object tracking. It has the potential to become a general technique in image processing and computer vision applications. Concepts and knowledge from several areas in mathematics such as Set Theory, Fuzzy Set Theory, Graph Theory, Numerical Analysis, Topology, Discrete Geometry, Computational Complexity, and Algorithm Design and Analysis have been applied to the work of this thesis.
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Chhabra, Vikram. "Reconstructing specular objects with image based rendering using color caching." Link to electronic thesis, 2001. http://www.wpi.edu/Pubs/ETD/Available/etd-0427101-111305.
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Thesis (M.S.)--Worcester Polytechnic Institute.Keywords: scene reconstruction vision, image based rendering, graphics, color consistency, specular objects. Includes bibliographical references (p. 56-57).
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Hesami, Reyhaneh. "Large-scale range data acquisition and segmentation." Swinburne Research Bank, 2009. http://hdl.handle.net/1959.3/66878.
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Thesis (PhD) - Swinburne University of Technology, Faculty of Engineering and Industrial Sciences, 2009.A thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, 2009. Typescript. Bibliography: p. 144-165.
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Liu, Hongze. "A High-Resolution Microscopic Electrical Impedance Imaging Modality: Scanning Impedance Imaging." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1729.pdf.
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Boyer, Edmond. "Reconstruction de surfaces d'objets courbes en vision par ordinateur." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 1996. http://tel.archives-ouvertes.fr/tel-00584012.
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De par les récents progrès de l'informatique dans le domaine de l'imagerie, il est dorénavant possible de manipuler des surfaces d'objets réels à partir des ordinateurs. Un des besoins qui en découle concerne l'acquisition de ces surfaces. Dans ce document, nous nous penchons sur le problème de la reconstruction de surfaces d'objets courbes à partir de séquences d'images. Les contours images de ce type d'objets, les contours occultants, constituent une riche source d'informations sur la géométrie de la surface de l'objet. Il est en particulier possible d'estimer les propriétés locales de la surface lorsqu'une séquence d'au moins trois contours est disponible. Nous présentons dans ce cadre une méthodologie de reconstruction de surfaces. Celle-ci permet de passer d'une séquence de contours occultants à une description de la partie de la surface observée correspondante, sous la forme de facettes triangulaires. Plusieurs aspects de la reconstruction liés aux contours occultants sont par ailleurs pris en compte pour améliorer les résultats: la correction des effets dûs au bruit présent dans l'ensemble du processus d'acquisition ainsi que la détection des parties non-visibles de la surface par les contours, les concavités par exemple. Les différentes étapes de la méthodologie sont illustrées tout au long du document par de nombreuses expérimentations sur des données réelles et synthétiques.
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Rosato, Matthew J. "Applying conformal mapping to the vertex correspondence problem for 3D face models." Diss., Online access via UMI:, 2007.
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Boufama, Boubakeur. "Reconstruction tridimensionnelle en vision par ordinateur : cas des caméras non étalonnées." Grenoble INPG, 1994. http://tel.archives-ouvertes.fr/tel-00005080.
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"la 4e de couverture indique : Cette thèse concerne principalement la reconstruction tridimensionnelle à partir d'images issues de caméras non étalonnées. Deux autres sujets liés à la reconstruction ont été traités: le calcul de la géométrie épipolaire et la mise en correspondance des points dans les imagesNous nous plaçons dans le cas général d'une séquence d'images obtenues avec une ou plusieurs caméras inconnues. Quand seuls les points observés dans les images sont utilisés la seule reconstruction possible est de type projective. Nous proposons d'abord une méthode pour calculer la reconstruction projective, ensuite, nous montrons comment passer d'une telle reconstruction à une reconstruction euclidienne. Ce passage utilise des contraintes euclidiennes issues de connaissances a priori sur la scène tridimensionnelle. Enfin, nous proposons une méthode de reconstruction euclidienne lorsque les paramètres intrinsèques des caméras sont approximativement connus. Cette méthode utilise un paramétrage permettant une grande stabilité dans les calculs
Toutes les méthodes proposées sont validées avec des exemples d'images réelles et simulées
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Erdem, Mehmet Erkut. "Image-based Extraction Of Material Reflectance Properties Of A 3d Object." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1128784/index.pdf.
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In this study, an appearance reconstruction method based on extraction of
material refl
ectance properties of a three-dimensional (3D) object from its twodimensional (2D) images is explained. One of the main advantages of this system is that the reconstructed object can be rendered in real-time with photorealistic quality in varying illumination conditions. Bidirectional Re&
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ectance Distribution Functions (BRDFs) are used in representing the re&
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ectance of the object. The re&
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ectance of the object is decomposed into di&
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use and specular components and each component is estimated seperately. While estimating the di&
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use components, illumination-invariant images of the object are computed from the input images, and a global texture of the object is extracted from these images by using surface particles. The specular re&
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ectance data are collected from the residual images obtained by taking di&
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erence between the input images and corresponding illumination-invariant images, and a Lafortune BRDF model is &
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tted to these data. At the rendering phase, the di&
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use and specular components are blended into each other to achieve a photorealistic appearance of the reconstructed object.
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Saracchini, Rafael Felipe Veiga 1984. "Métodos fotométricos para visão computacional." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275694.
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Orientador: Jorge StolfiTese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação
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Resumo: O principal objetivo desta tese de doutorado é o desenvolvimento e implementação de técnicas inovadoras para visão estereoscópica ou estéreo - a reconstrução de um modelo tridimensional de uma cena, a partir de duas ou mais imagens bidimensionais da mesma. Especificamente, estudamos e aprimoramos métodos de estéreo fotométrico, que utilizam imagens tomadas com mesmo ponto de vista sob várias condições de iluminação e determinam a normal à superfície da cena em cada pixel das imagens. Estas normais podem ser então integradas para gerar um mapa de alturas que fornece a terceira dimensão da cena. Consideramos principalmente métodos em que as condições de iluminação e o acabamento da superfície da cena são determinadas pela análise de imagens de objetos de referência (gabaritos) com forma conhecida. As contribuições desta tese consistem em: (1) desenvolvimento de gabaritos virtuais para eliminar o ruído presente nas imagens de gabaritos reais; (2) um método de grade bidimensional para determinação rápida das normais da cena; (3) uma abordagem robusta baseada em inferência bayesiana para determinação das normais na presença de anomalias de tonalização; e (4) dois métodos para integração multi-escala para mapas de normais que podem ser usados em mapas com lacunas e ruído. Investigamos também uma aplicação prática dessas técnicas: a captura da geometria da face de uma pessoa em movimento
Abstract: The main goal of this PhD thesis is the development and implementation of innovative techniques for stereo vision or stereo - the reconstruction of a tridimensional model of a scene from two or more two dimensional images. Specifically, we studied and improved photometric stereo methods, which use images taken from the same viewpoint under different lighting conditions, and determine the surface normal of the scene at each pixel. We mainly studied methods that determine the lighting conditions and surface finish by the analysis of images of reference objects (gauges or example objects) with known geometry. The contributions of this thesis consist of: (1) development of virtual example objects in order to eliminate noise and defects present in images of real example objects; (2) a 2D hashing grid method for fast normal computation; (3) a robust approach based in Bayesian inference for surface normal computation in the presence of shading anomalies, and (4) two methods for multi-scale normal map integration that can be used in maps with missing or noisy data. We also investigated a practical application of such methods: the capture of the 3D facial geometry of a person in movement
Doutorado
Ciência da Computação
Doutor em Ciência da Computação
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Gonzales, Marquez Mercedes Rocio. "Pre-alinhamento de imagens de profundidade via malhas simplificadas." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261218.
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Orientador: Wu Shin-TingTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: O pré-alinhamento de duas imagens de profundidade parcialmente sobrepostas de objetos rígidos consiste na determinação automática de uma transformação rígida T que coloca ambas imagens em um mesmo referencial. Ele deve ser independente da geometria da imagem e deve ser eficiente, no sentido de reduzir a complexidade temporal da tarefa de determinação e casamento de pares de correspondências. A solução mais popular consiste na extração de n pares de pontos correspondentes nas regiões comuns de ambas imagens para, a partir desses pares, estimar a transformação T. As técnicas existentes na literatura ainda apresentam diversas limitações quanto à restrição geométrica das imagens e à eficiência. Este trabalho propõe uma solução alternativa eficiente. Tendo como hipótese de que a forma de um objeto pode ser essencialmente capturada por um subconjunto finito dos seus pontos, esta tese propõe o uso de uma malha triangular simplificada, em lugar de uma imagem de profundidade densa, para reduzir o espaço de busca de correspondências. Propõe-se ainda a construção de um descritor, denominado triedro, com alta capacidade discriminante para possibilitar uma busca mais eficiente de correspondências no espaço reduzido de amostras. O algoritmo proposto foi validado através de testes com diversas imagens reais
Abstract: The crude registration of two partially overlapping range images from rigid objects consists of the determination of a rigid transformation T which brings both images into the same reference system. A crude registration should be independent of data geometry, and be efficient, in the sense that has low time complexity in finding the correspondence pairs. The most popular solution consists of extracting n pairs of correspondences in the overlapping regions and estimating from them the transformation T. Current works on crude registration still present drawbacks in relation to data geometry and efficiency. This work proposes an alternative solution for crude registration. Based on the hypothesis that the shape of an object is essentially captured by a finite subset of its points, this thesis proposes the use of a simplified triangular mesh, instead of a dense range image, to reduce the search space of correspondences. Besides, the construction of a descriptor, called trihedron is proposed. It has higher discriminating capacity which makes correspondence search still more efficient. The proposed algorithm has been validated through experiment tests with several real images
Doutorado
Engenharia de Computação
Doutor em Engenharia Elétrica
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Eren, Gönen. "3D scanning of transparent objects." Phd thesis, Université de Bourgogne, 2010. http://tel.archives-ouvertes.fr/tel-00584061.
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Many practical tasks in industry, such as automatic inspection or robot vision, often require scanning of three-dimensional shapes with non-contact techniques. However, transparent objects, such as those made of glass, still pose difficulties for classical scanning techniques. The reconstruction of surface geometry for transparent objects is complicated by the fact that light is transmitted through, refracted and in some cases reflected by the surface. Current approaches can only deal relatively well with sub-classes of objects. The algorithms are still very specific and not generally applicable. Furthermore, many techniques require considerable acquisition effort and careful calibration. This thesis proposes a new method of determining the surface shape of transparent objects. The method is based on local surface heating and thermal imaging. First, the surface of the object is heated with a laser source. A thermal image is acquired, and pixel coordinates of the heated point are calculated. Then, the 3D coordinates of the surface are computed using triangulation and the initial calibration of the system. The process is repeated by moving the transparent object to recover its surface shape. This method is called Scanning From Heating. Considering the laser beam as a point heating source and the surface of the object locally flat at the impact zone, the Scanning From Heating method is extended to obtain the surface normals of the object, in addition to the 3D world coordinates. A scanner prototype based on Scanning From Heating method has been developed during the thesis.
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Marashdeh, Qussai Mohammad. "Advances in electrical capacitance tomography." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1148591259.
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Gill, Sunbir. "Polygonal meshing for stereo video surface reconstruction /." 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR38774.
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Thesis (M.Sc.)--York University, 2007. Graduate Programme in Computer Science.Typescript. Includes bibliographical references (leaves118-124). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR38774
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"Practical Euclidean reconstruction of buildings." 2001. http://library.cuhk.edu.hk/record=b5890781.
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Chou Yun-Sum, Bailey.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references (leaves 89-92).
Abstracts in English and Chinese.
List of Symbol
Chapter Chapter 1 --- Introduction
Chapter 1.1 --- The Goal: Euclidean Reconstruction --- p.1
Chapter 1.2 --- Historical background --- p.2
Chapter 1.3 --- Scope of the thesis --- p.2
Chapter 1.4 --- Thesis Outline --- p.3
Chapter Chapter 2 --- An introduction to stereo vision and 3D shape reconstruction
Chapter 2.1 --- Homogeneous Coordinates --- p.4
Chapter 2.2 --- Camera Model
Chapter 2.2.1 --- Pinhole Camera Model --- p.5
Chapter 2.3 --- Camera Calibration --- p.11
Chapter 2.4 --- Geometry of Binocular System --- p.14
Chapter 2.5 --- Stereo Matching --- p.15
Chapter 2.5.1 --- Accuracy of Corresponding Point --- p.17
Chapter 2.5.2 --- The Stereo Matching Approach --- p.18
Chapter 2.5.2.1 --- Intensity-based stereo matching --- p.19
Chapter 2.5.2.2 --- Feature-based stereo matching --- p.20
Chapter 2.5.3 --- Matching Constraints --- p.20
Chapter 2.6 --- 3D Reconstruction --- p.22
Chapter 2.7 --- Recent development on self calibration --- p.24
Chapter 2.8 --- Summary of the Chapter --- p.25
Chapter Chapter 3 --- Camera Calibration
Chapter 3.1 --- Introduction --- p.26
Chapter 3.2 --- Camera Self-calibration --- p.27
Chapter 3.3 --- Self-calibration under general camera motion --- p.27
Chapter 3.3.1 --- The absolute Conic Based Techniques --- p.28
Chapter 3.3.2 --- A Stratified approach for self-calibration by Pollefeys --- p.33
Chapter 3.3.3 --- Pollefeys self-calibration with Absolute Quadric --- p.34
Chapter 3.3.4 --- Newsam's self-calibration with linear algorithm --- p.34
Chapter 3.4 --- Camera Self-calibration under specially designed motion sequence
Chapter 3.4. 1 --- Hartley's self-calibration by pure rotations --- p.35
Chapter 3.4.1.1 --- Summary of the Algorithm
Chapter 3.4.2 --- Pollefeys self-calibration with variant focal length --- p.36
Chapter 3.4.2.1 --- Summary of the Algorithm
Chapter 3.4.3 --- Faugeras self-calibration of a 1D Projective Camera --- p.38
Chapter 3.5 --- Summary of the Chapter --- p.39
Chapter Chapter 4 --- Self-calibration under Planar motions
Chapter 4.1 --- Introduction --- p.40
Chapter 4.2 --- 1D Projective Camera Self-calibration --- p.41
Chapter 4.2.1 --- 1-D camera model --- p.42
Chapter 4.2.2 --- 1-D Projective Camera Self-calibration Algorithms --- p.44
Chapter 4.2.3 --- Planar motion detection --- p.45
Chapter 4.2.4 --- Self-calibration under horizontal planar motions --- p.46
Chapter 4.2.5 --- Self-calibration under three different planar motions --- p.47
Chapter 4.2.6 --- Result analysis on self-calibration Experiments --- p.49
Chapter 4.3 --- Essential Matrix and Triangulation --- p.51
Chapter 4.4 --- Merge of Partial 3D models --- p.51
Chapter 4.5 --- Summary of the Reconstruction Algorithms --- p.53
Chapter 4.6 --- Experimental Results
Chapter 4.6.1 --- Experiment 1 : A Simulated Box --- p.54
Chapter 4.6.2 --- Experiment 2 : A Real Building --- p.57
Chapter 4.6.3 --- Experiment 3 : A Sun Flower --- p.58
Chapter 4.7 --- Conclusion --- p.59
Chapter Chapter 5 --- Building Reconstruction using a linear camera self- calibration technique
Chapter 5.1 --- Introduction --- p.60
Chapter 5.2 --- Metric Reconstruction from Partially Calibrated image
Chapter 5.2.1 --- Partially Calibrated Camera --- p.62
Chapter 5.2.2 --- Optimal Computation of Fundamental Matrix (F) --- p.63
Chapter 5.2.3 --- Linearly Recovering Two Focal Lengths from F --- p.64
Chapter 5.2.4 --- Essential Matrix and Triangulation --- p.66
Chapter 5.3 --- Experiments and Discussions --- p.67
Chapter 5.4 --- Conclusion --- p.71
Chapter Chapter 6 --- Refine the basic model with detail depth information by a Model-Based Stereo technique
Chapter 6.1 --- Introduction --- p.72
Chapter 6.2 --- Model Based Epipolar Geometry
Chapter 6.2.1 --- Overview --- p.74
Chapter 6.2.2 --- Warped offset image preparation --- p.76
Chapter 6.2.3 --- Epipolar line calculation --- p.78
Chapter 6.2.4 --- Actual corresponding point finding by stereo matching --- p.80
Chapter 6.2.5 --- Actual 3D point generated by Triangulation --- p.80
Chapter 6.3 --- Summary of the Algorithms --- p.81
Chapter 6.4 --- Experiments and discussions --- p.83
Chapter 6.5 --- Conclusion --- p.85
Chapter Chapter 7 --- Conclusions
Chapter 7.1 --- Summary --- p.86
Chapter 7.2 --- Future Work --- p.88
BIBLIOGRAPHY --- p.89
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Mharte, Amit Narendra Kumar Piyush. "Normal estimation and surface reconstruction of large point clouds." Diss., 2006. http://etd.lib.fsu.edu/theses/available/04102006-172149.
Full textAbstract:
Thesis (M.S.)--Florida State University, 2006.Advisor: Piyush Kumar, Florida State University, College of Arts and Sciences, Dept. of Computer Science. Title and description from dissertation home page (viewed June 7, 2006). Document formatted into pages; contains viii, 45 pages. Includes bibliographical references.
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"Recovering 3D geometry from single line drawings." 2011. http://library.cuhk.edu.hk/record=b5894516.
Full textAbstract:
Xue, Tianfan.Thesis (M.Phil.)--Chinese University of Hong Kong, 2011.
Includes bibliographical references (p. 52-55).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Previous Approaches on Face Identification --- p.3
Chapter 1.1.1 --- Face Identification --- p.3
Chapter 1.1.2 --- General Objects --- p.4
Chapter 1.1.3 --- Manifold Objects --- p.7
Chapter 1.2 --- Previous Approaches on 3D Reconstruction --- p.9
Chapter 1.3 --- Our approach for Face Identification --- p.11
Chapter 1.4 --- Our approach for 3D Reconstruction --- p.13
Chapter 2 --- Face Detection --- p.14
Chapter 2.1 --- GAFI and its Face Identification Results --- p.15
Chapter 2.2 --- Our Face Identification Approach --- p.17
Chapter 2.2.1 --- Real Face Detection --- p.18
Chapter 2.2.2 --- The Weak Face Adjacency Theorem --- p.20
Chapter 2.2.3 --- Searching for Type 1 Lost Faces --- p.22
Chapter 2.2.4 --- Searching for Type 2 Lost Faces --- p.23
Chapter 2.3 --- Experimental Results --- p.25
Chapter 3 3 --- D Reconstruction --- p.30
Chapter 3.1 --- Assumption and Terminology --- p.30
Chapter 3.2 --- Finding Cuts from a Line Drawing --- p.34
Chapter 3.2.1 --- Propositions for Finding Cuts --- p.34
Chapter 3.2.2 --- Searching for Good Cuts --- p.35
Chapter 3.3 --- Separation of a Line Drawing from Cuts --- p.38
Chapter 3.4 3 --- D Reconstruction from a Line Drawing --- p.45
Chapter 3.5 --- Experiments --- p.45
Chapter 4 --- Conclusion --- p.50
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"Parameter optimization and learning for 3D object reconstruction from line drawings." 2010. http://library.cuhk.edu.hk/record=b5894303.
Full textAbstract:
Du, Hao.Thesis (M.Phil.)--Chinese University of Hong Kong, 2010.
Includes bibliographical references (p. 61).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- 3D Reconstruction from 2D Line Drawings and its Applications --- p.1
Chapter 1.2 --- Algorithmic Development of 3D Reconstruction from 2D Line Drawings --- p.3
Chapter 1.2.1 --- Line Labeling and Realization Problem --- p.4
Chapter 1.2.2 --- 3D Reconstruction from Multiple Line Drawings --- p.5
Chapter 1.2.3 --- 3D Reconstruction from a Single Line Drawing --- p.6
Chapter 1.3 --- Research Problems and Our Contributions --- p.12
Chapter 2 --- Adaptive Parameter Setting --- p.15
Chapter 2.1 --- Regularities in Optimization-Based 3D Reconstruction --- p.15
Chapter 2.1.1 --- Face Planarity --- p.18
Chapter 2.1.2 --- Line Parallelism --- p.19
Chapter 2.1.3 --- Line Verticality --- p.19
Chapter 2.1.4 --- Isometry --- p.19
Chapter 2.1.5 --- Corner Orthogonality --- p.20
Chapter 2.1.6 --- Skewed Facial Orthogonality --- p.21
Chapter 2.1.7 --- Skewed Facial Symmetry --- p.22
Chapter 2.1.8 --- Line Orthogonality --- p.24
Chapter 2.1.9 --- Minimum Standard Deviation of Angles --- p.24
Chapter 2.1.10 --- Face Perpendicularity --- p.24
Chapter 2.1.11 --- Line Collinearity --- p.25
Chapter 2.1.12 --- Whole Symmetry --- p.25
Chapter 2.2 --- Adaptive Parameter Setting in the Objective Function --- p.26
Chapter 2.2.1 --- Hill-Climbing Optimization Technique --- p.28
Chapter 2.2.2 --- Adaptive Weight Setting and its Explanations --- p.29
Chapter 3 --- Parameter Learning --- p.33
Chapter 3.1 --- Construction of A Large 3D Object Database --- p.33
Chapter 3.2 --- Training Dataset Generation --- p.34
Chapter 3.3 --- Parameter Learning Framework --- p.37
Chapter 3.3.1 --- Evolutionary Algorithms --- p.38
Chapter 3.3.2 --- Reconstruction Error Calculation --- p.39
Chapter 3.3.3 --- Parameter Learning Algorithm --- p.41
Chapter 4 --- Experimental Results --- p.45
Chapter 4.1 --- Adaptive Parameter Setting --- p.45
Chapter 4.1.1 --- Use Manually-Set Weights --- p.45
Chapter 4.1.2 --- Learn the Best Weights with Different Strategies --- p.48
Chapter 4.2 --- Evolutionary-Algorithm-Based Parameter Learning --- p.49
Chapter 5 --- Conclusions and Future Work --- p.53
Bibliography --- p.55
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Rao, Swetcha. "3D ENDOSCOPY VIDEO GENERATED USING DEPTH INFERENCE: CONVERTING 2D TO 3D." 2013. http://hdl.handle.net/1805/3443.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)A novel algorithm was developed to convert raw 2-dimensional endoscope videos into 3-dimensional view. Minimally invasive surgeries aided with 3D view of the invivo site have shown to reduce errors and improve training time compared to those with 2D view. The novelty of this algorithm is that two cues in the images have been used to develop the 3D. Illumination is the rst cue used to nd the darkest regions in the endoscopy images in order to locate the vanishing point(s). The second cue is the presence of ridge-like structures in the in-vivo images of the endoscopy image sequence. Edge detection is used to map these ridge-like structures into concentric ellipses with their common center at the darkest spot. Then, these two observations are used to infer the depth of the endoscopy videos; which then serves to convert them from 2D to 3D. The processing time is between 21 seconds to 20 minutes for each frame, on a 2.27GHz CPU. The time depends on the number of edge pixels present in the edge-detection image. The accuracy of ellipse detection was measured to be 98.98% to 99.99%. The algorithm was tested on 3 truth images with known ellipse parameters and also on real bronchoscopy image sequences from two surgical procedures. Out of 1020 frames tested in total, 688 frames had single vanishing point while 332 frames had two vanishing points. Our algorithm detected the single vanishing point in 653 of the 688 frames and two vanishing points in 322 of the 332 frames.
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Joshi, Abhishek Shriram. "Image Processing and Super Resolution Methods for a Linear 3D Range Image Scanning Device for Forensic Imaging." 2013. http://hdl.handle.net/1805/3414.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)In the last few decades, forensic science has played a significant role in bringing criminals to justice. Shoe and tire track impressions found at the crime scene are important pieces of evidence since the marks and cracks on them can be uniquely tied to a person or vehicle respectively. We have designed a device that can generate a highly accurate 3-Dimensional (3D) map of an impression without disturbing the evidence. The device uses lasers to detect the changes in depth and hence it is crucial to accurately detect the position of the laser. Typically, the forensic applications require very high resolution images in order to be useful in prosecutions of criminals. Limitations of the hardware technology have led to the use of signal and image processing methods to achieve high resolution images. Super Resolution is the process of generating higher resolution images from multiple low resolution images using knowledge about the motion and the properties of the imaging geometry. This thesis presents methods for developing some of the image processing components of the 3D impression scanning device. In particular, the thesis describes the following two components: (i) methods to detect the laser stripes projected onto the impression surface in order to calculate the deformations of the laser stripes due to 3D surface shape being scanned, and (ii) methods to improve the resolution of the digitized color image of the impression by utilizing multiple overlapping low resolution images captured during the scanning process and super resolution techniques.
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Mukherjee, Prateep. "Active geometric model : multi-compartment model-based segmentation & registration." Thesis, 2014. http://hdl.handle.net/1805/4908.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)We present a novel, variational and statistical approach for model-based segmentation. Our model generalizes the Chan-Vese model, proposed for concurrent segmentation of multiple objects embedded in the same image domain. We also propose a novel shape descriptor, namely the Multi-Compartment Distance Functions or mcdf. Our proposed framework for segmentation is two-fold: first, several training samples distributed across various classes are registered onto a common frame of reference; then, we use a variational method similar to Active Shape Models (or ASMs) to generate an average shape model and hence use the latter to partition new images. The key advantages of such a framework is: (i) landmark-free automated shape training; (ii) strict shape constrained model to fit test data. Our model can naturally deal with shapes of arbitrary dimension and topology(closed/open curves). We term our model Active Geometric Model, since it focuses on segmentation of geometric shapes. We demonstrate the power of the proposed framework in two important medical applications: one for morphology estimation of 3D Motor Neuron compartments, another for thickness estimation of Henle's Fiber Layer in the retina. We also compare the qualitative and quantitative performance of our method with that of several other state-of-the-art segmentation methods.
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Yang, Huanyi. "Performance analysis of EM-MPM and K-means clustering in 3D ultrasound breast image segmentation." 2014. http://hdl.handle.net/1805/3875.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)Mammographic density is an important risk factor for breast cancer, detecting and screening at an early stage could help save lives. To analyze breast density distribution, a good segmentation algorithm is needed. In this thesis, we compared two popularly used segmentation algorithms, EM-MPM and K-means Clustering. We applied them on twenty cases of synthetic phantom ultrasound tomography (UST), and nine cases of clinical mammogram and UST images. From the synthetic phantom segmentation comparison we found that EM-MPM performs better than K-means Clustering on segmentation accuracy, because the segmentation result fits the ground truth data very well (with superior Tanimoto Coefficient and Parenchyma Percentage). The EM-MPM is able to use a Bayesian prior assumption, which takes advantage of the 3D structure and finds a better localized segmentation. EM-MPM performs significantly better for the highly dense tissue scattered within low density tissue and for volumes with low contrast between high and low density tissues. For the clinical mammogram, image segmentation comparison shows again that EM-MPM outperforms K-means Clustering since it identifies the dense tissue more clearly and accurately than K-means. The superior EM-MPM results shown in this study presents a promising future application to the density proportion and potential cancer risk evaluation.
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Cong, Shan. "Morphometric analysis of hippocampal subfields : segmentation, quantification and surface modeling." Thesis, 2014. http://hdl.handle.net/1805/5808.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)Object segmentation, quantification, and shape modeling are important areas inmedical image processing. By combining these techniques, researchers can find valuableways to extract and represent details on user-desired structures, which can functionas the base for subsequent analyses such as feature classification, regression, and prediction. This thesis presents a new framework for building a three-dimensional (3D) hippocampal atlas model with subfield information mapped onto its surface, with which hippocampal surface registration can be done, and the comparison and analysis can be facilitated and easily visualized. This framework combines three powerful tools for automatic subcortical segmentation and 3D surface modeling. Freesurfer and Functional magnetic resonance imaging of the brain's Integrated Registration and Segmentation Tool (FIRST) are employed for hippocampal segmentation and quantification, while SPherical HARMonics (SPHARM) is employed for parametric surface modeling. This pipeline is shown to be effective in creating a hippocampal surface atlas using the Alzheimer's Disease Neuroimaging Initiative Grand Opportunity and phase 2 (ADNI GO/2) dataset. Intra-class Correlation Coefficients (ICCs) are calculated for evaluating the reliability of the extracted hippocampal subfields. The complex folding anatomy of the hippocampus offers many analytical challenges, especially when informative hippocampal subfields are usually ignored in detailed morphometric studies. Thus, current research results are inadequate to accurately characterize hippocampal morphometry and effectively identify hippocampal structural changes related to different conditions. To address this challenge, one contribution of this study is to model the hippocampal surface using a parametric spherical harmonic model, which is a Fourier descriptor for general a 3D surface. The second contribution of this study is to extend hippocampal studies by incorporating valuable hippocampal subfield information. Based on the subfield distributions, a surface atlas is created for both left and right hippocampi. The third contribution is achieved by calculating Fourier coefficients in the parametric space. Based on the coefficient values and user-desired degrees, a pair of averaged hippocampal surface atlas models can be reconstructed. These contributions lay a solid foundation to facilitate a more accurate, subfield-guided morphometric analysis of the hippocampus and have the potential to reveal subtle hippocampal structural damage associated.
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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.
Full textAbstract:
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.