Reconstruction of continuous signals from a number of their discrete samples is central to digital signal processing. Digital devices can only process discrete data and thus processing the continuous signals requires discretization. After discretization, possibility of unique reconstruction of the source signals from their samples is crucial. The classical sampling theory provides bounds on the sampling rate for unique source reconstruction, known as the Nyquist sampling rate. Recently a new sampling scheme, Compressive Sensing (CS), has been formulated for sparse signals. CS is an active area of research in signal processing. It has revolutionized the classical sampling theorems and has provided a new scheme to sample and reconstruct sparse signals uniquely, below Nyquist sampling rates. A signal is called (approximately) sparse when a relatively large number of its elements are (approximately) equal to zero. For the class of sparse signals, sparsity can be viewed as prior information about the source signal. CS has found numerous applications and has improved some image acquisition devices. Interesting instances of CS can happen, when apart from sparsity, side information is available about the source signals. The side information can be about the source structure, distribution, etc. Such cases can be viewed as extensions of the classical CS. In such cases we are interested in incorporating the side information to either improve the quality of the source reconstruction or decrease the number of the required samples for accurate reconstruction. A general CS problem can be transformed to an equivalent optimization problem. In this thesis, a special case of CS with side information about the feasible region of the equivalent optimization problem is studied. It is shown that in such cases uniqueness and stability of the equivalent optimization problem still holds. Then, an efficient reconstruction method is proposed. To demonstrate the practical value of the proposed scheme, the algorithm is applied on two real world applications: image deblurring in optical imaging and surface reconstruction in the gradient field. Experimental results are provided to further investigate and confirm the effectiveness and usefulness of the proposed scheme.

abstract: This research focuses on the stress and structure evolution observed in-situ during the earliest stages of thin film growth in Cu on Au(111)-reconstruction. For the research, an ultra high vacuum-scanning tunneling microscopy (UHV-STM) system was modified to have the additional capabilities of in-situ deposition and in-situ stress evolution monitoring. The design and fabrication processes for the modifications are explained in detail. The deposition source enabled imaging during the deposition of Cu thin films, while also being columnar enough to avoid negatively impacting the function of the microscope. It was found that the stress-induced changes in piezo voltage occurred over a substantially longer time scale and larger piezo scale than used during imaging, allowing for the deconvolution of the two sources of piezo voltage change. The intrinsic stress evolution observed at the onset of Cu growth was tensile in character and reached a maximum of 0.19 N/m at approximately 0.8ML, with an average tensile slope of 1.0GPa. As the film thickness increased beyond 0.8 ML, the stress became less tensile as the observation of disordered stripe and trigon patterns of misfit dislocations began to appear. The transport of atoms from the surface of enlarged Cu islands into the strained layer played an important role in this stage, because they effectively reduce the activation barrier for the formation of the observed surface structures. A rich array of structures were observed in the work presented here including stripe, disordered stripe and trigon patterns co-existing in a single Cu layer. Heteroepitaxial systems in existing literature showed a uniform structure in the single layer. The non-uniform structures in the single layer of this work may be attributed to the room temperature Cu growth, which can kinetically limit uniform pattern formation. The development of the UHV-STM system with additional capabilities for this work is expected to contribute to research for the stress and structure relationships of many other heteroepitaxial systems. / Dissertation/Thesis / Ph.D. Materials Science and Engineering 2012

L'analyse du comportement des petits animaux de laboratoire tels que rats et souris est fondamentale en recherche biologique. L'objectif de cette thèse est de faire des mesures anatomiques sur le squelette de souris à partir de vidéos et de démontrer la robustesse de ces mesures par une validation quantitative. Les principales difficultés viennent du sujet d'étude, la souris, qui, vu comme un objet géométrique, peut subir de grandes déformations très rapidement et des conditions expérimentales qui ne permettent pas d'obtenir des flux vidéos de même qualité que pour l'étude de l'humain. Au vu de ces difficultés, nous nous concentrons tout d'abord dans le Chapitre 2 sur la mise en place d'une méthode de recalage de squelette à l'aide de marqueurs collés sur la peau de l'animal. On montre que les effets de couplage non-rigide entre peau et squelette peuvent être contre-carrés par une pondération de l'influence des différents marqueurs dans la cinématique inverse. Cela nous permet de justifier que, malgré ce couplage non rigide, des informations sur la peau de l'animal sont suffisantes pour recaler de manière précise et robuste les structures squelettiques. Nous développons pour cela une chaîne de traitement de données morphologiques qui nous permet de proposer un modèle générique d'animation du squelette des souris. La méthode de cinématique inverse pondérée est validée grâce à des vidéos radiographiques. Ayant justifié de l'utilisation de points à la surface de la peau (l'enveloppe) pour recaler le squelette, nous proposons dans le Chapitre 3 un nouveau modèle de déformation de l'enveloppe. Ce modèle, appelé OQR (pour Oriented Quads Rigging, gréage de quadrilatères orientés), est une structure géométrique flexible possédant les bonnes propriétés de déformation de l'animation par cage. A l'instar des squelettes d'animation, elle permet d'avoir une paramétrisation haut-niveau de la morphologie et du mouvement. Nous montrons également comment, grâce à cette bonne déformation de l'enveloppe, nous pouvons utiliser les sommets du maillage déformé comme marqueurs pour la méthode de recalage du squelette du Chapitre 2. Dans les chapitres 2 et 3, nous avons construit un modèle de souris qui permet d'animer en même temps l'enveloppe et le squelette. Ce modèle est paramétré par OQR. Nous proposons donc dans le Chapitre 4 une méthode d'extraction de ces paramètres à partir soit d'une séquence de maillage sans cohérence temporelle soir directement à partir d'images segmentées. Pour contraindre le problème, nous faisons l'apprentissage d'un espace réduit de configurations d'OQR vraisemblables. / Analysing the behaviour of small laboratory animals such as rats and mice is paramount in clinical research. We aim at recovering reliable anatomical measures of the skeleton of mice from videos and at demonstrating the robustness of these measures with quantitative validation. The most challenging aspects of this thesis reside in the study subject, mice, that is highly deformable, very fast and in the experimental conditions that do not allow for video data equivalent to what can be obtained with human subjects. In regards to the first challenge, we first focus on a marker-based tracking method with markers glued on the skin of the animal in Chapter 2. We show that the effects of the non-rigid mapping between skin and bones can be pre-empted by a weighting of the influences of the different markers in inverse kinematics. This allows us to demonstrate that, despite the non-rigid mapping, features on the skin of the animal can be used to accurately and robustly track the skeletal structures. We therefore develop a pipeline to process morphological data that leads to a generic animation model for the skeleton of mice. The weighted inverse kinematics method is validated with X-ray videos. Chapter 2 proves that points on the surface of the animal (on the envelope) can be used to track the skeletal structures. As a result, in Chapter 3, we propose a new deformation model of the envelope. This model, called OQR (Oriented Quads Rigging), is a flexible geometrical structure that has the nice deformation properties of cage-based animation. Like animation skeletons, OQR gives a high-level representation of the morphology and of the motion. We also show how, thanks to a well-deformed envelope, we can use a sub-set of the vertices of the deformed mesh as markers to apply the method of tracking of skeletal structures developed in Chapter 2. With Chapters 2 and 3, we have built a model of mice that allows us to animate at the same time the envelope and the skeleton. This model is parameterised by OQR. In Chapter 4, we therefore propose a method to recover the OQR parameters from either a sequence of meshes without temporal coherence or directly from segmented images. To regularise the tracking problem, we learn a manifold of plausible OQR configurations.

As b-splines são utilizadas em sistemas CAD/CAM/CAE para representar e definir curvas e superfícies complexas, sendo adotada pelos principais padrões da computação gráfica devido a características como representação matemática de forma compacta, flexibilidade e transformações afins. Em sistemas de aquisição de dados 3D e sistemas CAM-CNC integrados, a utilização da b-spline na transferência de informações geométricas e na reconstrução da superfície de objetos resulta em um significativo incremento na eficiência do processo, geralmente implementado em sistemas embarcados. Nestes sistemas embarcados, integrados no auxílio a máquinas de manufatura, a utilização de FPGAs é incipiente, sem circuitos para b-splines disponibilizados em lógica reconfigurável de circuito aberto (open core), razão pela qual este projeto propõe o desenvolvimento de um circuito de geração b-spline aberto, em um sistema embarcado FPGA, utilizando algoritmos adaptados para os circuitos, elaborados em linguagem Verilog HDL, padronizada para a síntese de circuitos em lógica reconfigurável. Os circuitos foram desenvolvidos, utilizando-se um barramento de dados padronizado em circuito aberto, nas seguintes implementações para processamento paralelo das b-splines: o BFEA, o método baseado em funções base fixas, ambos projetados para circuitos integrados, e o fast Cox-de Boor, desenvolvido para FPGAs. Foram comparados o tempo de execução e o consumo de recursos disponíveis no FPGA utilizado, entre cada implementação. Os resultados evidenciaram que os circuitos de funções base fixas apresentaram o processamento mais rápido para a geração de b-splines em um FPGA, com um tempo de execução em média 20% menor em relação às outras implementações. Os circuitos BFEA apresentaram a menor utilização de elementos lógicos, em média 50% menor em relação aos outros circuitos implementados. O circuito fast Cox-de Boor apresentou a melhor escalabilidade, devido à modularidade da implementação, com tempos de execução similares aos circuitos de funções base fixas. / The b-splines are used in CAD/CAM/CAE systems to represent and define complex curves and surfaces, being adopted by the main computer graphics standards due to features like compact mathematic representation, flexibility and affine transformations. In 3D acquisition systems and integrated CAM-CNC systems, the use of the b-spline in the geometric information data transfer and in the object surface reconstruction results in a increase in the process efficiency, generally implemented in embedded systems. In these embedded systems, integrated in the aid to manufacturing machines, the use of FPGAs is incipient, without available b-splines open core circuits in reconfigurable logic, the reason why this project propose the development of a b-spline generation open core circuit, in a FPGA embedded system, using adaptated algorithms for the circuits, made in Verilog HDL language, standardized for the circuit synthesis in reconfigurable logic. The circuits were developed, using an open core standardized data bus, in the following implementations of b-spline parallel processing: the BFEA, fixed basis functions based method, both designed for integrated circuits, and the fast Cox-de Boor, developed for FPGAs. The execution time and available resource consumption in the FPGA were compared, between each implementation. The results show that the fixed basis functions circuits presented the fastest processing for the b-splines generation in a FPGA, with a 20% mean execution time reduction in relation to the other implementations. The BFEA circuits presented the lowest logic elements use, in mean 50% fewer in relation to the other implemented circuits. The fast Cox-De Boor circuit presented the best scalability, due to the implementation modularity, with execution times similar to the fixed basis functions circuits.

Orientador: Ricardo Machado Leite de Barros / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-17T21:46:00Z (GMT). No. of bitstreams: 1 Lodovico_Angelica_D.pdf: 9939519 bytes, checksum: 5a0820d3dc5340beb35664df30053206 (MD5) Previous issue date: 2011 / Resumo: Este trabalho teve como objetivo propor e avaliar um método baseado em projeção de luz para reconstrução e análise da superfície do tronco durante a respiração. O método consistiu em: projetar uma malha de marcas circulares sobre a superfície anterior e posterior do tronco; registrar as superfícies do tronco através de quatro câmeras de vídeo durante a respiração; segmentar as imagens e rastrear as marcas projetadas através de técnicas de pré-processamento de imagens, operações morfológicas e algoritmos de detecção; estabelecer uma correspondência entre as marcas nas seqüências de imagens registradas pelas câmeras; reconstruir as coordenadas 3D das marcas; reconstruir a superfície do tronco a partir da nuvem de pontos desordenada usando o método QHULL. Medidas de variação de volume e perímetro do tronco ao longo do ciclo respiratório e mapas de contorno foram usados para analisar a superfície reconstruída. A acurácia da medida de volume foi avaliada através da comparação entre a medida de volume de um manequim de tronco masculino obtida por imersão e através da metodologia proposta. Um exemplo de aplicação da análise foi realizado com dois sujeitos com formas e tamanhos de tronco distintos, um do sexo feminino com escoliose idiopática severa e um do sexo masculino sem deformações na coluna vertebral. A variação do volume do tronco foi comparada com a variação do volume de ar trocado durante o ciclo respiratório medido através da espirometria. O método foi capaz de reconstruir com alto nível de detalhamento a superfície do tronco possibilitando a identificação de estruturas anatômica e a diferenciação da forma do tronco dura ate as fases do ciclo respiratório. A acurácia relativa na determinação do volume foi de 2,9%. A variação do volume do tronco durante a respiração apresentou um sinal coerente com o ciclo respiratório e apresentou altos valores de correlação (r=0.988) quando comparado com o volume de ar trocado. A análise da superfície através de mapas de contorno mostrou ser uma ferramenta promissora na identificação de deformações da superfície. Podemos concluir que a proposta do uso de um método baseado em de projeção de luz foi adequada para reconstrução e análise da superfície do tronco durante a respiração / Abstract: This study aimed to propose and evaluate a method based on light projection for trunk surface reconstruction and analysis during respiration. The method consisted of: to project a grid of circular markers on the anterior and posterior surface of the trunk; to register the trunk surfaces by four video cameras during respiration; to segment the video stream and track the projected markers using pre-processing techniques, morphological operators and detection algorithms; to establish a correspondence between the markers in the sequences of images recorded by the cameras; to reconstruct the 3D coordinates of the markers; to reconstruct the trunk surface from cloud of unorganized points using the QHULL method. Measures of volume and perimeter along the respiratory cycle and contour maps were used to analyze the reconstructed surface. The accuracy of volume measurement was assessed by comparing the volume of a male torso mannequin obtained by water displacement and through the proposed method. An application example of the analysis was conducted with two subjects with different shapes and sizes of different body, a female with severe idiopathic scoliosis and a male without spine deformation. The change in trunk volume was compared with the air exchanged volume variation during the respiratory cycle measured by spirometry. The method was able to reconstruct with high level of detail the trunk surface allowing the identification of anatomical structures and differentiation of the trunk shape during the phases of the respiratory cycle. The relative accuracy in determining the volume was 2.9%. The variation of the trunk volume during respiration showed a coherent signal with the respiratory cycle and showed high correlation (r2 = 0,983) when compared with the volume of air exchanged. The analysis of the surface through contour maps proved to be a promising tool in the identification of the surface deformations. We can conclude that the proposed use of a method based on projection of light was adequate for reconstruction and analysis of the trunk surface during respiration / Doutorado / Biodinamica do Movimento Humano / Doutor em Educação Física

We consider the problem of reconstructing a surface from noisy samples by approximating the point set with non-uniform rational B-spline surfaces. We focus on the fact that the knot sequences should also be part of the unknown variables that include the control points and the weights in order to find their optimal positions. We show how to set up the free knot problem such that constrained nonlinear optimization can be applied efficiently. We describe in detail a parallel implementation of our approach that give almost linear speedup. Finally, we provide numerical results obtained on the Chemnitzer Linux Cluster supercomputer.

This report evaluates possibilities to combine volumetric ultrasound (us) data together with the recent work published on advanced skin rendering techniques. We focus mainly on how to filter us data and localize surfaces within us data. We also evaluate recent skin rendering techniques in order to have a good understanding of what is needed from the us for rendering realistic skin. us data is acquired using sonography and have a low signal-to-noise ratio by nature, this makes it harder to extract surfaces compared to other medical data acquisition methods such as ct and mr. This report present an algorithm which implements a variational classification technique to emphasize surfaces within us and using a rbf network to fit an implicit function to these surfaces. Using this approach presented we have successfully extract smooth meshes from the noisy us data.

To create a digital model of the surface of some object from a setof points, representing positions on the surface of this object, requiresinformation about the relationship between the points. This informa-tion is not immediatly accessible. Thus, for creating such a model itis necessary to establish relationsships between the points of the set.In addition, it should be possible to render the resulting modelas efficiently as possible. Modern graphics cards offer to send vertexinformations as triangle strips; by using triangle strips the informationabout the triangles can be compressed.This work is about a method for retrieving information about therelations between points in an unstructered spatial point set and trans-forming this information into triangle strips. It is based on the convexlayers of a planar point set and an algorithm for triangulating theannuli of the convex layers, which uses the Rotating Calipers.

The Diploma thesis deals with object surface reconstruction by means of confocal microscope. It includes part of mathematical theory which is associated with this problem. The mathematical algorithm of the object surface reconstruction is illustrated. This Diploma thesis result is the application development for this reconstruction. The thesis also include the results of specific object.

This thesis deals with methods of edema measuring. In my work, I designed hardware and software solutions for a device reconstructing surface of the limb part. Purpose of my work is evaluating discussing possibilities of this device. For making 3D reconstruction of scene from 2D images I made reconstruction program. For acquisition of images a device controlled by Arduino platform was constructed, the whole device is realized in program language Matlab. In the end of the thesis is described, how to improve the device for using in real conditions.