242 research outputs found

    Mosaicking video with parallax.

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    Cheung Man-Tai.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.Includes bibliographical references (leaves 81-84).Abstracts in English and Chinese.List of Figures --- p.viList of Tables --- p.viiiChapter Chapter 1. --- Introduction --- p.1Chapter 1.1. --- Background --- p.1Chapter 1.1.1. --- Parallax --- p.2Chapter 1.2. --- Literature Review --- p.3Chapter 1.3. --- Research Objective --- p.6Chapter 1.4. --- Organization of Thesis --- p.6Chapter Chapter 2. --- The 3-Image Algorithm --- p.1Chapter 2.1. --- Projective Reconstruction --- p.10Chapter 2.2. --- Epipolar Geometry and Fundamental Matrix --- p.11Chapter 2.3. --- Determine the Projective Mapping --- p.12Chapter 2.3.1. --- Conditions for Initial Matches --- p.13Chapter 2.3.2. --- Obtaining the Feature Correspondence --- p.17Chapter 2.4. --- Registering Pixel Element --- p.21Chapter 2.4.1. --- Single Homography Approach --- p.22Chapter 2.4.2. --- Multiple Homography Approach --- p.23Chapter 2.4.3. --- Triangular Patches Clustering --- p.24Chapter 2.4.3.1. --- Delaunay Triangulation --- p.25Chapter 2.5. --- Mosaic Construction --- p.29Chapter Chapter 3. --- The n-Image Algorithm --- p.31Chapter Chapter 4. --- The Uneven-Sampling-Rate n-Image Algorithm --- p.34Chapter 4.1. --- Varying the Reference-Target Images Separation --- p.35Chapter 4.2. --- Varying the Target-Intermediate Images Separation --- p.38Chapter Chapter 5. --- Experiments --- p.43Chapter 5.1. --- Experimental Setup --- p.43Chapter 5.1.1. --- Measuring the Performance --- p.43Chapter 5.2. --- Experiments on the 3-Image Algorithm --- p.44Chapter 5.2.1. --- Planar Scene --- p.44Chapter 5.2.2. --- Comparison between a Global Parametric Transformation and the 3-Image Algorithm --- p.46Chapter 5.2.3. --- Generic Scene --- p.49Chapter 5.2.4. --- The Triangular Patches Clustering against the Multiple Homography Approach --- p.52Chapter 5.3. --- Experiments on the n-Image Algorithm --- p.56Chapter 5.3.1. --- Initial Experiment on the n-Image Algorithm --- p.56Chapter 5.3.2. --- Another Experiment on the n-Image Algorithm --- p.58Chapter 5.3.3. --- the n-Image Algorithm over a Longer Image Stream --- p.61Chapter 5.4. --- Experiments on the Uneven-Sampling-Rate n-Image Algorithm --- p.65Chapter 5.4.1. --- Varying Reference-Target Images Separation --- p.65Chapter 5.4.2. --- Varying Target-Intermediate Images Separation --- p.69Chapter 5.4.3. --- Comparing the Uneven-Sampling-Rate n-Image Algorithm and Global Transformation Method --- p.73Chapter Chapter 6. --- Conclusion and Discussion --- p.76Bibliography --- p.8

    Connected Attribute Filtering Based on Contour Smoothness

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    Forum Bildverarbeitung 2022

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    Bildverarbeitung verknüpft das Fachgebiet die Sensorik von Kameras – bildgebender Sensorik – mit der Verarbeitung der Sensordaten – den Bildern. Daraus resultiert der besondere Reiz dieser Disziplin. Der vorliegende Tagungsband des „Forums Bildverarbeitung“, das am 24. und 25.11.2022 in Karlsruhe als Veranstaltung des Karlsruher Instituts für Technologie und des Fraunhofer-Instituts für Optronik, Systemtechnik und Bildauswertung stattfand, enthält die Aufsätze der eingegangenen Beiträge

    Forum Bildverarbeitung 2022

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    Robust computational intelligence techniques for visual information processing

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    The third part is exclusively dedicated to the super-resolution of Magnetic Resonance Images. In one of these works, an algorithm based on the random shifting technique is developed. Besides, we studied noise removal and resolution enhancement simultaneously. To end, the cost function of deep networks has been modified by different combinations of norms in order to improve their training. Finally, the general conclusions of the research are presented and discussed, as well as the possible future research lines that are able to make use of the results obtained in this Ph.D. thesis.This Ph.D. thesis is about image processing by computational intelligence techniques. Firstly, a general overview of this book is carried out, where the motivation, the hypothesis, the objectives, and the methodology employed are described. The use and analysis of different mathematical norms will be our goal. After that, state of the art focused on the applications of the image processing proposals is presented. In addition, the fundamentals of the image modalities, with particular attention to magnetic resonance, and the learning techniques used in this research, mainly based on neural networks, are summarized. To end up, the mathematical framework on which this work is based on, ₚ-norms, is defined. Three different parts associated with image processing techniques follow. The first non-introductory part of this book collects the developments which are about image segmentation. Two of them are applications for video surveillance tasks and try to model the background of a scenario using a specific camera. The other work is centered on the medical field, where the goal of segmenting diabetic wounds of a very heterogeneous dataset is addressed. The second part is focused on the optimization and implementation of new models for curve and surface fitting in two and three dimensions, respectively. The first work presents a parabola fitting algorithm based on the measurement of the distances of the interior and exterior points to the focus and the directrix. The second work changes to an ellipse shape, and it ensembles the information of multiple fitting methods. Last, the ellipsoid problem is addressed in a similar way to the parabola

    Registro espacial 2D–3D para a inspeção remota de subestações de energia

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    Remote inspection and supervisory control are critical features for smart factories, civilian surveillance, power systems, among other domains. For reducing the time to make decisions, operators must have both a high situation awareness, implying a considerable amount of data to be presented, and minimal sensory load. Recent research suggests the adoption of computer vision techniques for automatic inspection, as well as virtual reality (VR) as an alternative to traditional SCADA interfaces. Nevertheless, although VR may provide a good representation of a substation’s state, it lacks some real-time information, available from online field cameras and microphones. Since these two sources of information (VR and field information) are not integrated into one single solution, we miss the opportunity of using VR as a SCADA-aware remote inspection tool, during operation and disaster-response routines. This work discusses a method to augment virtual environments of power substations with field images, enabling operators to promptly see a virtual representation of the inspected area's surroundings. The resulting environment is integrated with an image-based state inference machine, continuously checking the inferred states against the ones reported by the SCADA database. Whenever a discrepancy is found, an alarm is triggered and the virtual camera can be immediately teleported to the affected region, speeding up system reestablishment. The solution is based on a client-server architecture and allows multiple cameras deployed in multiple substations. Our results concern the quality of the 2D–3D registration and the rendering framerate for a simple scenario. The collected quantitative metrics suggest good camera pose estimations and registrations, as well as an arguably optimal rendering framerate for substations' equipment inspection.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCEMIG - Companhia Energética de Minas GeraisCNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas GeraisTese (Doutorado)A inspeção remota e o controle supervisório são requisitos críticos para fábricas modernas, vigilância de civis, sistemas de energia e outras áreas. Para reduzir o tempo da tomada de decisão, os operadores precisam de uma elevada consciência da situação em campo, o que implica em uma grande quantidade de dados a serem apresentados, mas com menor carga sensorial possível. Estudos recentes sugerem a adoção de técnicas de visão computacional para inspeção automática, e a Realidade Virtual (VR) como uma alternativa às interfaces tradicionais do SCADA. Entretanto, apesar de fornecer uma boa representação do estado da subestação, os ambientes virtuais carecem de algumas informações de campo, provenientes de câmeras e microfones. Como essas duas fontes de dados (VR e dispositivos de captura) não são integrados em uma única solução, perde-se a oportunidade de usar VR como uma ferramenta de inspeção remota conectada ao SCADA, durante a operação e rotinas de respostas a desastres. Este trabalho trata de um método para aumentar ambientes virtuais de subestações com imagens de campo, permitindo aos operadores a rápida visualização de uma representação virtual do entorno da área monitorada. O ambiente resultante é integrado com uma máquina de inferência estados por imagens, comparando continuamente os estados inferidos com aqueles reportados pela base SCADA. Na ocasião de uma discrepância, um alarme é gerado e possibilita que a câmera virtual seja imediatamente teletransportada para a região afetada, acelerando o processo de retomada do sistema. A solução se baseia em uma arquitetura cliente-servidor e permite múltiplas câmeras presentes em múltiplas subestações. Os resultados dizem respeito à qualidade do registro 2D–3D e à taxa de renderização para um cenário simples. As métricas quantitativas coletadas sugerem bons níveis de registro e estimativa de pose de câmera, além de uma taxa ótima de renderização para fins de inspeção de equipamentos em subestações

    CT Scanning

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    Since its introduction in 1972, X-ray computed tomography (CT) has evolved into an essential diagnostic imaging tool for a continually increasing variety of clinical applications. The goal of this book was not simply to summarize currently available CT imaging techniques but also to provide clinical perspectives, advances in hybrid technologies, new applications other than medicine and an outlook on future developments. Major experts in this growing field contributed to this book, which is geared to radiologists, orthopedic surgeons, engineers, and clinical and basic researchers. We believe that CT scanning is an effective and essential tools in treatment planning, basic understanding of physiology, and and tackling the ever-increasing challenge of diagnosis in our society
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