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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Distributed System of Pan/tilt Cameras for 3D Tracking

Woo, David C. 07 1900 (has links)
This thesis describes a distributed system of cameras for visually tracking feature points in 3D. The concept of a network of cameras is introduced. Two or more calibrated cameras from a network of cameras are used to triangulate the location of a point in 3D based on camera positions and pan/tilt angles. A survey of methods for interior and exterior calibration is provided and a method suitable for multiple cameras in arbitrary positions has been implemented. A low-cost camera unit has been designed using off-the-shelf components that include a small CCD board camera and two servo-controlled mechanisms for pan and tilt. Experimental results demonstrate the performance of a network of cameras. / Thesis / Master of Engineering (ME)
2

Localization and Surveillance using Wireless Sensor Network and Pan/Tilt Camera

Desai, Pratikkumar U. 26 May 2009 (has links)
No description available.
3

Realtidsstyrning av robotiserad kameraplattform / Real time control of robotized camera platform

Axelsson, Jonathan, Hultberg, Carl January 2018 (has links)
Försvarets materielverk (FMV), som förser Svenska försvaret med materiel, har en del av sin organisation belägen i Karlsborg nämligen test och evaluering av markstridssystem. Fotogruppen på test och evaluering önskar realtidsstyra en robotiserad kameraplattform av märket Vinten med hjälp av diverse olika positionsgivande system i form av joystick, Doppler-positionsradar, deras självutvecklade system UNIPOS samt en predikterad bana för avlossade projektiler. Projektets huvudsakliga mål blev därför att skapa ett styrsystem för att kontrollera kameraplattformen med hjälp av nämnda indatakällor. Den teoretiska referensramen samt litteraturstudien gav projektets deltagare den kunskapsbas, inom seriell kommunikation och dataprotokoll, som krävdes för att genomföra projektet. De gav även förståelse för hur tidigare liknande arbeten sett ut och valde utifrån detta att följa systemutvecklingsmodellen Rational Unified process (RUP). FMV uttryckte önskemål om att den huvudsakliga styrenheten skulle vara en PC för att möjliggöra fjärrstyrning samt enkel vidareutveckling av systemet. RUP användes för att strukturera upp arbetet samt säkerställa kvalitén på slutprodukten. Utvecklingsprocessen består, enligt RUP’s struktur, av ett antal iterationer som alla tillför någon funktion till systemet. I samråd och nära samarbete med personal på FMV utvecklades systemet och testades succesivt för att säkerställa kvalitén. En enkel manual togs även fram för att förenkla användandet av systemet. Samtliga önskade indatakällor behandlades på något sätt i projektet och resultatet blev ett portabelt system som kan köras på vilken PC som helst. Tester med drönare, granatkastare samt ett stegsvar har utförts för att verifiera att systemets funktion uppfyller de krav som satts upp samt utvärdera systemets möjligheter och begränsningar. Testen visade att realtidsstyrning är möjlig till viss grad med samtliga system och att systemets begränsningar ligger i fördröjningarna som finns både i signalöverföring samt kameraplattformens inbyggda filter för mjuka rörelser. / The Swedish Defence Material Administration (FMV) that supplies materials to the Swedish military, has a part of its organization located in Karlsborg called test and evaluation of land combat systems. The photogroup of test and evaluation wishes to control a robotized camera platform, of the brand Vinten, in real time using a number of different positioning systems like joystick, Doppler-position radar, their self-constructed system UNIPOS and using a predicted trajectory of a launched projectile. The main goal of the project is therefore to create a control system to maneuver the camera platform with the assistance of mentioned data sources. The theoretical framework and literature review gave the members of the project the knowledge base, in serial communication and data protocols, needed to complete the project and gave understanding about earlier similar projects and choose to follow the structure of the systems development model Rational Unified Process (RUP). FMV wanted the main control unit to be a PC to be able to remotely control the system and to be able to make further developments. RUP was used to give the work structure and to make sure the quality of the end product was satisfactory. The development process consists, in accordance with the RUP structure, of a number of iterations that all add some function to the system. In close cooperation with the staff at FMV the system is developed and continuously tested to ensure the quality. A simple manual has been developed to make usage of the system easier. Every data source wanted by FMV has been handled in some way throughout the project and the result was a portable system that can be ran on any PC. Tests using drones, grenade launchers and a response-test was performed to verify that the functions of the system lives up to the goals that were set up and to evaluate the systems possibilities and limitations. The tests showed that real time control is possible to some extent with all systems and that the limitations lies in the delays that exists both in signal transfers and in the camera platforms built in filters for soft movements.
4

PERFORMANCE OF PAN-TILT TRACKER BASED ON THE PIN-HOLE LENS MODEL

Mehta, Vikas Chandra 01 January 2009 (has links)
In the modern day, recognition and tracking of face or the iris is potentially one of the most powerful ways of differentiating between an authentic person and an imposter. Our method uses stereo vision to track the 3-Dimensional coordinates of a target equivalent to a person’s eyes and using a pan-tilt unit we target these areas for additional processing such as iris or facial imaging. One of the most important parts involved in tracking is the way the pan-tilt unit is calibrated. There have been techniques in the past where PTZ (Pan-tilt-zoom) digital camera has been used and calibrated using self calibration techniques involving a checker board calibration grid but the tracking error was found to be large in these techniques. We introduce a more accurate form of calibration of the pantilt unit using photogrammetric calibration technique and view the pan-tilt unit as an emulation of a Pinhole Lens Model to detect and track the target. The system is demonstrated on ideal targets.
5

ROBUST BACKGROUND SUBTRACTION FOR MOVING CAMERAS AND THEIR APPLICATIONS IN EGO-VISION SYSTEMS

Sajid, Hasan 01 January 2016 (has links)
Background subtraction is the algorithmic process that segments out the region of interest often known as foreground from the background. Extensive literature and numerous algorithms exist in this domain, but most research have focused on videos captured by static cameras. The proliferation of portable platforms equipped with cameras has resulted in a large amount of video data being generated from moving cameras. This motivates the need for foundational algorithms for foreground/background segmentation in videos from moving cameras. In this dissertation, I propose three new types of background subtraction algorithms for moving cameras based on appearance, motion, and a combination of them. Comprehensive evaluation of the proposed approaches on publicly available test sequences show superiority of our system over state-of-the-art algorithms. The first method is an appearance-based global modeling of foreground and background. Features are extracted by sliding a fixed size window over the entire image without any spatial constraint to accommodate arbitrary camera movements. Supervised learning method is then used to build foreground and background models. This method is suitable for limited scene scenarios such as Pan-Tilt-Zoom surveillance cameras. The second method relies on motion. It comprises of an innovative background motion approximation mechanism followed by spatial regulation through a Mega-Pixel denoising process. This work does not need to maintain any costly appearance models and is therefore appropriate for resource constraint ego-vision systems. The proposed segmentation combined with skin cues is validated by a novel application on authenticating hand-gestured signature captured by wearable cameras. The third method combines both motion and appearance. Foreground probabilities are jointly estimated by motion and appearance. After the mega-pixel denoising process, the probability estimates and gradient image are combined by Graph-Cut to produce the segmentation mask. This method is universal as it can handle all types of moving cameras.
6

Hardware Implementation Of An Active Feature Tracker For Surveillance Applications

Solmaz, Berkan 01 July 2008 (has links) (PDF)
The integration of image sensors and high performance processors into embedded systems enabled the development of intelligent vision systems. In this thesis, we developed an active autonomous system to be used for surveillance applications. The proposed system detects a single moving object in the field of view automatically and tracks it in a wide area by controlling the pan-tilt-zoom features of the camera. The system can also go to an alarm state to warn the user. The processing unit of the system is a Texas Instruments DM642 Evaluation Module which is a low-cost high performance video &amp / imaging development platform designed to develop and evaluate video based applications.
7

Exterior inspection of an aircraft using a Pan-Tilt-Zoom camera and a 3D scanner moved by a mobile robot : 2D image processing and 3D point cloud analysis / Inspection de l'extérieur d'un aéronef à partir d'une caméra Pan-Tilt-Zoom et d'un scanner 3D portés par un robot mobile : analyse d'images et de nuages de points 3D

Jovančević, Igor 21 November 2016 (has links)
Cette thèse s’inscrit dans le cadre d’un projet industriel multi-partenaires ayant pour objectif le développement d’un robot mobile collaboratif (un cobot), autonome dans ses mouvements au sol, capable de réaliser l’inspection visuelle d’un aéronef, à la fois en phase de petite ou grande maintenance dans un hangar ou en phase de pré-vol sur le tarmac d’un aéroport. Le cobot est équipé de capteurs lui permettant d’effectuer ses tâches de navigation autonome, mais également d’un ensemble de capteurs optiques constituant la tête d’inspection : une caméra orientable Pan-Tilt-Zoom et un scanner 3D qui délivrent respectivement des données sous forme d’images 2D et de nuages de points 3D. L’objectif de la thèse est de développer des algorithmes d’analyse d’images 2D et de nuages de points 3D, afin d’établir un diagnostic sur l’état de l’avion et son aptitude à voler. Nous avons développé des algorithmes pour vérifier certains éléments de l’appareil, tels que valves, portes, capteurs, pneus ou moteurs, et également pour détecter et caractériser des dommages 3D sur le fuselage (impacts, rayures, etc.). Nous avons exploité dans nos algorithmes les connaissances a priori disponibles, en particulier le modèle 3D CAO de l’avion (un AIRBUS A320 dans le cadre de nos essais). Durant ces travaux de la thèse, nous avons pu répondre à deux besoins (parfois antagonistes) : développer des algorithmes d’inspection rapides et robustes, mais également répondre aux exigences spécifiques d’un projet industriel qui visait à développer un prototype opérationnel. Nous nous sommes attachés à développer des algorithmes les plus génériques possibles, de manière à ce qu’ils puissent être utilisés pour d’autres types d’inspection, tels que l’inspection de bâtiments ou de navires par exemple. Nous avons aussi contribué au développement du prototype (robot mobile équipé de capteurs) en développant le module de contrôle des capteurs d’inspection et en intégrant nos codes sur le robot avec les autres modules développés par les partenaires. Le prototype a fait l’objet de nombreux essais en hangar de maintenance ou sur tarmac. / This thesis makes part of an industry oriented multi-partners project aimed at developing a mobile collaborative robot (a cobot), autonomous in its movements on the ground, capable of performing visual inspection of an aircraft during short or long maintenance procedures in the hangar or in the pre-flight phase on the tarmac. The cobot is equipped with sensors for realizing its navigation tasks as well as with a set of optical sensors which constitute the inspection head: an orientable Pan-Tilt-Zoom visible light camera and a three-dimensional scanner, delivering data in the format of two-dimensional images and three-dimensional point clouds, respectively. The goal of the thesis is to propose original approaches for processing 2D images and 3D clouds, with intention to make a decision with respect to the flight readiness of the airplane. We developed algorithms for verification of the aircraft items such as vents, doors, sensors, tires or engine as well as for detection and characterization of three-dimensional damages on the fuselage. We integrated a-priori knowledge on the airplane structure, notably numerical three-dimensional CAD model of the Airbus-A320. We argue that with investing effort to develop robust enough algorithms and with the help of existing optical sensors to acquire suitable data, we can come up with non-invasive, accurate, and time-efficient system for automatic airplane exterior inspection. The thesis work was placed in between two main requirements: develop inspection algorithms which could be as general as possible and also meet the specific requirements of an industry oriented project. Often, these two goals do not go along and the balance had to be made. On one side, we were aiming to design and assess the approaches that can be employed on other large structures, for ex. buildings, ships. On the other hand, writing source code for controlling sensors as well as integrating our whole developed source code with other modules on the real-time robotic system, were necessary in order to demonstrate the feasibility of our robotic prototype.
8

Algoritmos para composição automática defotografias. / Algorithms for automatic composition of photographs.

CAVALCANTI, Cláudio Sebastião Vasconcelos da Cunha. 17 August 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-08-17T13:42:57Z No. of bitstreams: 1 CLÁUDIO SABASTIÃO VASCONCELOS DA CUNHA CAVALCANTI - DISSERTAÇÃO PPGCC 2007..pdf: 19270985 bytes, checksum: b54c266f6cdb98e2cbbf305285b6ffdf (MD5) / Made available in DSpace on 2018-08-17T13:42:57Z (GMT). No. of bitstreams: 1 CLÁUDIO SABASTIÃO VASCONCELOS DA CUNHA CAVALCANTI - DISSERTAÇÃO PPGCC 2007..pdf: 19270985 bytes, checksum: b54c266f6cdb98e2cbbf305285b6ffdf (MD5) Previous issue date: 2007-07-30 / Além de ser uma das mais populares formas de arte, a fotografia também é uma forma de lazer e ferramenta de trabalho. Com a redução dos preços e a conseqüente popularização dos equipamentos e acessórios necessários à fotografia, especialmente o preço das câmeras digitais, é crescente o interesse por novos algoritmos e ferramentas que favoreçam a captura de imagens com maior qualidade. Diante do exposto, a presente dissertação objetivou a proposição e desenvolvimento de algoritmos capazes de detectar e corrigir falhas na composição fotográfica. As regras de composição fotográfica, em geral, são heurísticas utilizadas por fotógrafos que se difundiram a ponto de serem denominadas de “regras”. Mesmo não sendo consenso entre os fotógrafos, é possível que a implementação destas regras possa levar um fotógrafo amador, sem conhecimento prévio de fotografia, a produzir fotografias de alta qualidade e teor profissional. Neste trabalho são propostas duas alternativas para a correção da composição: um método para correção on-line, no qual a foto final só é obtida após satisfeitas algumas condições de qualidade, e outro para a correção off-line, o qual classifica (ou modifica) a imagem a posteriori. Para tanto, são utilizados algoritmos destinados à detecção e correção de problemas no posicionamento do tema. Os resultados foram avaliados em dois experimentos. No primeiro experimento, os usuários concordaram em até 65% com os resultados obtidos pelo sistema, através de uma análise subjetiva. No segundo experimento,foi mostrado como é possível, utilizando-se apenas uma câmera Pan-Tilt-Zoom (câmera dotada de três graus de liberdade sendo dois de rotação e um do campo de visão),localizar e fotografar pessoas em um determinado ambiente a partir das regras de composição desenvolvidas. / Besides being one of the most popular forms of art, photography is often used for a wide variety of purposes, including professional and entertainment ones. Nowadays, since cameras (specially digital ones) are less expensive and more popular, there is an increasing need for tools to help photographers (both amateurs and professionals) to obtain photographs of better quality. Within this context, algorithms for detection and correction of errors on the composition of a photograph are proposed in this work. Photographic composition rules are heuristics used by photographers, which became so wides pread that they are now also known as“rules”. Photographers, however, are not unanimous about the use of some of those rules. Despite of that it is possible that the use of photographic composition rules can improve the quality of amateur photographs, leveling them to a professional standard. In this dissertation, two approaches are proposed to automate composition rules: an on-line method, in which a picture is only taken when a number of conditions is satisfied; and an off-line method,which classifiers or corrects the image after it has been acquired. Hence, algorithms for detecting and correcting problems on subject positioning are used. Two experiments were used to evaluate the performance of the system. The first one shows that users agree with the correction performed on 65% of the photographs, through a subjective analysis. By using only a Pan-Tilt-Zoom camera and the composition rules implemented in this work, the second experiment shows howto locate and photograph human subjects ina given environment.
9

Calibration de systèmes de caméras et projecteurs dans des applications de création multimédia

Bélanger, Lucie 12 1900 (has links)
Ce mémoire s'intéresse à la vision par ordinateur appliquée à des projets d'art technologique. Le sujet traité est la calibration de systèmes de caméras et de projecteurs dans des applications de suivi et de reconstruction 3D en arts visuels et en art performatif. Le mémoire s'articule autour de deux collaborations avec les artistes québécois Daniel Danis et Nicolas Reeves. La géométrie projective et les méthodes de calibration classiques telles que la calibration planaire et la calibration par géométrie épipolaire sont présentées pour introduire les techniques utilisées dans ces deux projets. La collaboration avec Nicolas Reeves consiste à calibrer un système caméra-projecteur sur tête robotisée pour projeter des vidéos en temps réel sur des écrans cubiques mobiles. En plus d'appliquer des méthodes de calibration classiques, nous proposons une nouvelle technique de calibration de la pose d'une caméra sur tête robotisée. Cette technique utilise des plans elliptiques générés par l'observation d'un seul point dans le monde pour déterminer la pose de la caméra par rapport au centre de rotation de la tête robotisée. Le projet avec le metteur en scène Daniel Danis aborde les techniques de calibration de systèmes multi-caméras. Pour son projet de théâtre, nous avons développé un algorithme de calibration d'un réseau de caméras wiimotes. Cette technique basée sur la géométrie épipolaire permet de faire de la reconstruction 3D d'une trajectoire dans un grand volume à un coût minime. Les résultats des techniques de calibration développées sont présentés, de même que leur utilisation dans des contextes réels de performance devant public. / This thesis focuses on computer vision applications for technological art projects. Camera and projector calibration is discussed in the context of tracking applications and 3D reconstruction in visual arts and performance art. The thesis is based on two collaborations with québécois artists Daniel Danis and Nicolas Reeves. Projective geometry and classical camera calibration techniques, such as planar calibration and calibration from epipolar geometry, are detailed to introduce the techniques implemented in both artistic projects. The project realized in collaboration with Nicolas Reeves consists of calibrating a pan-tilt camera-projector system in order to adapt videos to be projected in real time on mobile cubic screens. To fulfil the project, we used classical camera calibration techniques combined with our proposed camera pose calibration technique for pan-tilt systems. This technique uses elliptic planes, generated by the observation of a point in the scene while the camera is panning, to compute the camera pose in relation to the rotation centre of the pan-tilt system. The project developed in collaboration with Daniel Danis is based on multi-camera calibration. For this studio theatre project, we developed a multi-camera calibration algorithm to be used with a wiimote network. The technique based on epipolar geometry allows 3D reconstruction of a trajectory in a large environment at a low cost. The results obtained from the camera calibration techniques implemented are presented alongside their application in real public performance contexts.
10

Calibration de systèmes de caméras et projecteurs dans des applications de création multimédia

Bélanger, Lucie 12 1900 (has links)
Ce mémoire s'intéresse à la vision par ordinateur appliquée à des projets d'art technologique. Le sujet traité est la calibration de systèmes de caméras et de projecteurs dans des applications de suivi et de reconstruction 3D en arts visuels et en art performatif. Le mémoire s'articule autour de deux collaborations avec les artistes québécois Daniel Danis et Nicolas Reeves. La géométrie projective et les méthodes de calibration classiques telles que la calibration planaire et la calibration par géométrie épipolaire sont présentées pour introduire les techniques utilisées dans ces deux projets. La collaboration avec Nicolas Reeves consiste à calibrer un système caméra-projecteur sur tête robotisée pour projeter des vidéos en temps réel sur des écrans cubiques mobiles. En plus d'appliquer des méthodes de calibration classiques, nous proposons une nouvelle technique de calibration de la pose d'une caméra sur tête robotisée. Cette technique utilise des plans elliptiques générés par l'observation d'un seul point dans le monde pour déterminer la pose de la caméra par rapport au centre de rotation de la tête robotisée. Le projet avec le metteur en scène Daniel Danis aborde les techniques de calibration de systèmes multi-caméras. Pour son projet de théâtre, nous avons développé un algorithme de calibration d'un réseau de caméras wiimotes. Cette technique basée sur la géométrie épipolaire permet de faire de la reconstruction 3D d'une trajectoire dans un grand volume à un coût minime. Les résultats des techniques de calibration développées sont présentés, de même que leur utilisation dans des contextes réels de performance devant public. / This thesis focuses on computer vision applications for technological art projects. Camera and projector calibration is discussed in the context of tracking applications and 3D reconstruction in visual arts and performance art. The thesis is based on two collaborations with québécois artists Daniel Danis and Nicolas Reeves. Projective geometry and classical camera calibration techniques, such as planar calibration and calibration from epipolar geometry, are detailed to introduce the techniques implemented in both artistic projects. The project realized in collaboration with Nicolas Reeves consists of calibrating a pan-tilt camera-projector system in order to adapt videos to be projected in real time on mobile cubic screens. To fulfil the project, we used classical camera calibration techniques combined with our proposed camera pose calibration technique for pan-tilt systems. This technique uses elliptic planes, generated by the observation of a point in the scene while the camera is panning, to compute the camera pose in relation to the rotation centre of the pan-tilt system. The project developed in collaboration with Daniel Danis is based on multi-camera calibration. For this studio theatre project, we developed a multi-camera calibration algorithm to be used with a wiimote network. The technique based on epipolar geometry allows 3D reconstruction of a trajectory in a large environment at a low cost. The results obtained from the camera calibration techniques implemented are presented alongside their application in real public performance contexts.

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