848 research outputs found

    A Methodology to Develop Computer Vision Systems in Civil Engineering: Applications in Material Testing and Fish Tracking

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    [Resumen] La Visión Artificial proporciona una nueva y prometedora aproximación al campo de la Ingeniería Civil, donde es extremadamente importante medir con precisión diferentes procesos. Sin embargo, la Visión Artificial es un campo muy amplio que abarca multitud de técnicas y objetivos, y definir una aproximación de desarrollo sistemática es problemático. En esta tesis se propone una nueva metodología para desarrollar estos sistemas considerando las características y requisitos de la Ingeniería Civil. Siguiendo esta metodología se han desarrollado dos sistemas: Un sistema para la medición de desplazamientos y deformaciones en imágenes de ensayos de resistencia de materiales. Solucionando las limitaciones de los actuales sensores físicos que interfieren con el ensayo y solo proporcionan mediciones en un punto y una dirección determinada. Un sistema para la medición de la trayectoria de peces en escalas de hendidura vertical, con el que se pretende solucionar las carencias en el diseño de escalas obteniendo información sobre el comportamiento de los peces. Estas aplicaciones representan contribuciones significativas en el área, y demuestran que la metodología definida e implementada proporciona un marco de trabajo sistemático y confiable para el desarrollo de sistemas de Visión Artificial en Ingeniería Civil.[Resumo] A Visión Artificial proporciona unha nova e prometedora aproximación ó campo da Enxeñería Civil, onde é extremadamente importante medir con precisión diferentes procesos. Sen embargo, a Visión Artificial é un campo moi amplo que abarca multitude de técnicas e obxectivos, e definir unha aproximación de desenvolvemento sistemática é problemático. En esta tese proponse unha nova metodoloxía para desenvolver estes sistemas considerando as características e requisitos da Enxeñería Civil. Seguindo esta metodoloxía desenvolvéronse dous sistemas: Un sistema para a medición de desprazamentos e deformacións en imaxes de ensaios de resistencia de materiais. Solucionando as limitacións dos actuais sensores físicos que interfiren co ensaio e só proporcionan medicións nun punto e nunha dirección determinada. Un sistema para a medición da traxectoria de peixes en escalas de fenda vertical, co que se pretende solucionar as carencias no deseño de escalas obtendo información sobre o comportamento dos peixes. Estas aplicacións representan contribucións significativas na área, e demostran que a metodoloxía definida e implementada proporciona un marco de traballo sistemático e confiable para o desenvolvemento de sistemas de Visión Artificial en Enxeñería Civil.[Abstract] Computer Vision provides a new and promising approach to Civil Engineering, where it is extremely important to measure with accuracy real world processes. However, Computer Vision is a broad field, involving several techniques and topics, and the task of defining a systematic development approach is problematic. In this thesis a new methodology is carried out to develop these systems attending to the special characteristics and requirements of Civil Engineering. Following this methodology, two systems were developed: A system to measure displacements from real images of material surfaces taken during strength tests. This technique solves the limitation of current physical sensors, which interfere with the assay and which are limited to obtaining measurements in a single point of the material and in a single direction of the movement. A system to measure the trajectory of fishes in vertical slot fishways, whose purpose is to solve current lacks in the design of fishways by providing information of fish behavior. These applications represent significant contributions to the field and show that the defined and implemented methodology provides a systematic and reliable framework to develop a Computer Vision system in Civil Engineering

    Energy efficient enabling technologies for semantic video processing on mobile devices

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    Semantic object-based processing will play an increasingly important role in future multimedia systems due to the ubiquity of digital multimedia capture/playback technologies and increasing storage capacity. Although the object based paradigm has many undeniable benefits, numerous technical challenges remain before the applications becomes pervasive, particularly on computational constrained mobile devices. A fundamental issue is the ill-posed problem of semantic object segmentation. Furthermore, on battery powered mobile computing devices, the additional algorithmic complexity of semantic object based processing compared to conventional video processing is highly undesirable both from a real-time operation and battery life perspective. This thesis attempts to tackle these issues by firstly constraining the solution space and focusing on the human face as a primary semantic concept of use to users of mobile devices. A novel face detection algorithm is proposed, which from the outset was designed to be amenable to be offloaded from the host microprocessor to dedicated hardware, thereby providing real-time performance and reducing power consumption. The algorithm uses an Artificial Neural Network (ANN), whose topology and weights are evolved via a genetic algorithm (GA). The computational burden of the ANN evaluation is offloaded to a dedicated hardware accelerator, which is capable of processing any evolved network topology. Efficient arithmetic circuitry, which leverages modified Booth recoding, column compressors and carry save adders, is adopted throughout the design. To tackle the increased computational costs associated with object tracking or object based shape encoding, a novel energy efficient binary motion estimation architecture is proposed. Energy is reduced in the proposed motion estimation architecture by minimising the redundant operations inherent in the binary data. Both architectures are shown to compare favourable with the relevant prior art

    Fusion of Imaging and Inertial Sensors for Navigation

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    The motivation of this research is to address the limitations of satellite-based navigation by fusing imaging and inertial systems. The research begins by rigorously describing the imaging and navigation problem and developing practical models of the sensors, then presenting a transformation technique to detect features within an image. Given a set of features, a statistical feature projection technique is developed which utilizes inertial measurements to predict vectors in the feature space between images. This coupling of the imaging and inertial sensors at a deep level is then used to aid the statistical feature matching function. The feature matches and inertial measurements are then used to estimate the navigation trajectory using an extended Kalman filter. After accomplishing a proper calibration, the image-aided inertial navigation algorithm is then tested using a combination of simulation and ground tests using both tactical and consumer- grade inertial sensors. While limitations of the Kalman filter are identified, the experimental results demonstrate a navigation performance improvement of at least two orders of magnitude over the respective inertial-only solutions

    Advanced Image Acquisition, Processing Techniques and Applications

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    "Advanced Image Acquisition, Processing Techniques and Applications" is the first book of a series that provides image processing principles and practical software implementation on a broad range of applications. The book integrates material from leading researchers on Applied Digital Image Acquisition and Processing. An important feature of the book is its emphasis on software tools and scientific computing in order to enhance results and arrive at problem solution

    Heritage Recording and 3D Modeling with Photogrammetry and 3D Scanning

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    The importance of landscape and heritage recording and documentation with optical remote sensing sensors is well recognized at international level. The continuous development of new sensors, data capture methodologies and multi-resolution 3D representations, contributes significantly to the digital 3D documentation, mapping, conservation and representation of landscapes and heritages and to the growth of research in this field. This article reviews the actual optical 3D measurement sensors and 3D modeling techniques, with their limitations and potentialities, requirements and specifications. Examples of 3D surveying and modeling of heritage sites and objects are also shown throughout the paper

    A Flexible, Low-Power, Programmable Unsupervised Neural Network Based on Microcontrollers for Medical Applications

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    We present an implementation and laboratory tests of a winner takes all (WTA) artificial neural network (NN) on two microcontrollers (μC) with the ARM Cortex M3 and the AVR cores. The prospective application of this device is in wireless body sensor network (WBSN) in an on-line analysis of electrocardiograph (ECG) and electromyograph (EMG) biomedical signals. The proposed device will be used as a base station in the WBSN, acquiring and analysing the signals from the sensors placed on the human body. The proposed system is equiped with an analog-todigital converter (ADC), and allows for multi-channel acquisition of analog signals, preprocessing (filtering) and further analysis

    Digital Image Processing

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    This book presents several recent advances that are related or fall under the umbrella of 'digital image processing', with the purpose of providing an insight into the possibilities offered by digital image processing algorithms in various fields. The presented mathematical algorithms are accompanied by graphical representations and illustrative examples for an enhanced readability. The chapters are written in a manner that allows even a reader with basic experience and knowledge in the digital image processing field to properly understand the presented algorithms. Concurrently, the structure of the information in this book is such that fellow scientists will be able to use it to push the development of the presented subjects even further
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