36 research outputs found

    Vision Sensors and Edge Detection

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    Vision Sensors and Edge Detection book reflects a selection of recent developments within the area of vision sensors and edge detection. There are two sections in this book. The first section presents vision sensors with applications to panoramic vision sensors, wireless vision sensors, and automated vision sensor inspection, and the second one shows image processing techniques, such as, image measurements, image transformations, filtering, and parallel computing

    Spectral Imaging for Mars Exploration

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    Multi-Projective Camera-Calibration, Modeling, and Integration in Mobile-Mapping Systems

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    Optical systems are vital parts of most modern systems such as mobile mapping systems, autonomous cars, unmanned aerial vehicles (UAV), and game consoles. Multi-camera systems (MCS) are commonly employed for precise mapping including aerial and close-range applications. In the first part of this thesis a simple and practical calibration model and a calibration scheme for multi-projective cameras (MPC) is presented. The calibration scheme is enabled by implementing a camera test field equipped with a customized coded target as FGI’s camera calibration room. The first hypothesis was that a test field is necessary to calibrate an MPC. Two commercially available MPCs with 6 and 36 cameras were successfully calibrated in FGI’s calibration room. The calibration results suggest that the proposed model is able to estimate parameters of the MPCs with high geometric accuracy, and reveals the internal structure of the MPCs. In the second part, the applicability of an MPC calibrated by the proposed approach was investigated in a mobile mapping system (MMS). The second hypothesis was that a system calibration is necessary to achieve high geometric accuracies in a multi-camera MMS. The MPC model was updated to consider mounting parameters with respect to GNSS and IMU. A system calibration scheme for an MMS was proposed. The results showed that the proposed system calibration approach was able to produce accurate results by direct georeferencing of multi-images in an MMS. Results of geometric assessments suggested that a centimeter-level accuracy is achievable by employing the proposed approach. A novel correspondence map is demonstrated for MPCs that helps to create metric panoramas. In the third part, the problem of real-time trajectory estimation of a UAV equipped with a projective camera was studied. The main objective of this part was to address the problem of real-time monocular simultaneous localization and mapping (SLAM) of a UAV. An angular framework was discussed to address the gimbal lock singular situation. The results suggest that the proposed solution is an effective and rigorous monocular SLAM for aerial cases where the object is near-planar. In the last part, the problem of tree-species classification by a UAV equipped with two hyper-spectral an RGB cameras was studied. The objective of this study was to investigate different aspects of a precise tree-species classification problem by employing state-of-art methods. A 3D convolutional neural-network (3D-CNN) and a multi-layered perceptron (MLP) were proposed and compared. Both classifiers were highly successful in their tasks, while the 3D-CNN was superior in performance. The classification result was the most accurate results published in comparison to other works.Optiset kuvauslaitteet ovat keskeisessä roolissa moderneissa konenäköön perustuvissa järjestelmissä kuten autonomiset autot, miehittämättömät lentolaitteet (UAV) ja pelikonsolit. Tällaisissa sovelluksissa hyödynnetään tyypillisesti monikamerajärjestelmiä. Väitöskirjan ensimmäisessä osassa kehitetään yksinkertainen ja käytännöllinen matemaattinen malli ja kalibrointimenetelmä monikamerajärjestelmille. Koodatut kohteet ovat keinotekoisia kuvia, joita voidaan tulostaa esimerkiksi A4-paperiarkeille ja jotka voidaan mitata automaattisesti tietokonealgoritmeillä. Matemaattinen malli määritetään hyödyntämällä 3-ulotteista kamerakalibrointihuonetta, johon kehitetyt koodatut kohteet asennetaan. Kaksi kaupallista monikamerajärjestelmää, jotka muodostuvat 6 ja 36 erillisestä kamerasta, kalibroitiin onnistuneesti ehdotetulla menetelmällä. Tulokset osoittivat, että menetelmä tuotti tarkat estimaatit monikamerajärjestelmän geometrisille parametreille ja että estimoidut parametrit vastasivat hyvin kameran sisäistä rakennetta. Työn toisessa osassa tutkittiin ehdotetulla menetelmällä kalibroidun monikamerajärjestelmän mittauskäyttöä liikkuvassa kartoitusjärjestelmässä (MMS). Tavoitteena oli kehittää ja tutkia korkean geometrisen tarkkuuden kartoitusmittauksia. Monikameramallia laajennettiin navigointilaitteiston paikannus ja kallistussensoreihin (GNSS/IMU) liittyvillä parametreillä ja ehdotettiin järjestelmäkalibrointimenetelmää liikkuvalle kartoitusjärjestelmälle. Kalibroidulla järjestelmällä saavutettiin senttimetritarkkuus suorapaikannusmittauksissa. Työssä myös esitettiin monikuville vastaavuuskartta, joka mahdollistaa metristen panoraamojen luonnin monikamarajärjestelmän kuvista. Kolmannessa osassa tutkittiin UAV:​​n liikeradan reaaliaikaista estimointia hyödyntäen yhteen kameraan perustuvaa menetelmää. Päätavoitteena oli kehittää monokulaariseen kuvaamiseen perustuva reaaliaikaisen samanaikaisen paikannuksen ja kartoituksen (SLAM) menetelmä. Työssä ehdotettiin moniresoluutioisiin kuvapyramideihin ja eteneviin suorakulmaisiin alueisiin perustuvaa sovitusmenetelmää. Ehdotetulla lähestymistavalla pystyttiin alentamaan yhteensovittamisen kustannuksia sovituksen tarkkuuden säilyessä muuttumattomana. Kardaanilukko (gimbal lock) tilanteen käsittelemiseksi toteutettiin uusi kulmajärjestelmä. Tulokset osoittivat, että ehdotettu ratkaisu oli tehokas ja tarkka tilanteissa joissa kohde on lähes tasomainen. Suorituskyvyn arviointi osoitti, että kehitetty menetelmä täytti UAV:n reaaliaikaiselle reitinestimoinnille annetut aika- ja tarkkuustavoitteet. Työn viimeisessä osassa tutkittiin puulajiluokitusta käyttäen hyperspektri- ja RGB-kameralla varustettua UAV-järjestelmää. Tavoitteena oli tutkia uusien koneoppimismenetelmien käyttöä tarkassa puulajiluokituksessa ja lisäksi vertailla hyperspektri ja RGB-aineistojen suorituskykyä. Työssä verrattiin 3D-konvoluutiohermoverkkoa (3D-CNN) ja monikerroksista perceptronia (MLP). Molemmat luokittelijat tuottivat hyvän luokittelutarkkuuden, mutta 3D-CNN tuotti tarkimmat tulokset. Saavutettu tarkkuus oli parempi kuin aikaisemmat julkaistut tulokset vastaavilla aineistoilla. Hyperspektrisen ja RGB-datan yhdistelmä tuotti parhaan tarkkuuden, mutta myös RGB-kamera yksin tuotti tarkan tuloksen ja on edullinen ja tehokas aineisto monille luokittelusovelluksille

    Human and Robotic Mission to Small Bodies: Mapping, Planning and Exploration

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    This study investigates the requirements, performs a gap analysis and makes a set of recommendations for mapping products and exploration tools required to support operations and scientific discovery for near- term and future NASA missions to small bodies. The mapping products and their requirements are based on the analysis of current mission scenarios (rendezvous, docking, and sample return) and recommendations made by the NEA Users Team (NUT) in the framework of human exploration. The mapping products that sat- isfy operational, scienti c, and public outreach goals include topography, images, albedo, gravity, mass, density, subsurface radar, mineralogical and thermal maps. The gap analysis points to a need for incremental generation of mapping products from low (flyby) to high-resolution data needed for anchoring and docking, real-time spatial data processing for hazard avoidance and astronaut or robot localization in low gravity, high dynamic environments, and motivates a standard for coordinate reference systems capable of describing irregular body shapes. Another aspect investigated in this study is the set of requirements and the gap analysis for exploration tools that support visualization and simulation of operational conditions including soil interactions, environment dynamics, and communications coverage. Building robust, usable data sets and visualisation/simulation tools is the best way for mission designers and simulators to make correct decisions for future missions. In the near term, it is the most useful way to begin building capabilities for small body exploration without needing to commit to specific mission architectures

    The ExoMars Spectral Tool (ExoSpec):an image analysis tool for ExoMars 2020 PanCam imagery

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    The upcoming launch of the European Space Agency (ESA) ExoMars 2020 rover signals a need for an analysis tool to be created which can exploit the multi- and hyperspectral data that will be returned by its Panoramic Camera (PanCam), Infrared Spectrometer for Mars (ISEM), and Close-UP Imager (CLUPI) instruments. Data processed by this analysis tool will be invaluable in (i) characterising the geology local to the ExoMars rover, (ii) relating ground-based observations to orbital Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) data, (iii) detecting evidence of past habitability on Mars, and (iv) identifying drilling locations. PanCam, ISEM, and CLUPI offer spectral analysis capabilities in both spatial (140-1310 microns/pixel at 2 m working distance) and spectral (440-3300 nm) dimensions. We have developed the ExoMars Spectral Tool (ExoSpec) which functions as a GUI-based extension to ENVI + IDL and performs steps from image import and compilation into ENVI.dat format, flat-fielding, radiometric correction, radiance-toreflectance (R∗) corrections using the in-scene Gretag MacBeth ColorCheckerTM, and calculation of spectral parameters. We demonstrate the functionality of ExoSpec at its current stage of development and illustrate its utility with results from field expeditions to Mars analogue terrains in: (i) geothermally altered basalts in Ńamafjall, Iceland, and (ii) layered alluvial plains deposits in Hanksville, USA, using ExoMars PanCam, ISEM, and CLUPI emulator instruments

    Assessment of the CORONA series of satellite imagery for landscape archaeology: a case study from the Orontes valley, Syria

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    In 1995, a large database of satellite imagery with worldwide coverage taken from 1960 until 1972 was declassified. The main advantages of this imagery known as CORONA that made it attractive for archaeology were its moderate cost and its historical value. The main disadvantages were its unknown quality, format, geometry and the limited base of known applications. This thesis has sought to explore the properties and potential of CORONA imagery and thus enhance its value for applications in landscape archaeology. In order to ground these investigations in a real dataset, the properties and characteristics of CORONA imagery were explored through the case study of a landscape archaeology project working in the Orontes Valley, Syria. Present-day high-resolution IKONOS imagery was integrated within the study and assessed alongside CORONA imagery. The combination of these two image datasets was shown to provide a powerful set of tools for investigating past archaeological landscape in the Middle East. The imagery was assessed qualitatively through photointerpretation for its ability to detect archaeological remains, and quantitatively through the extraction of height information after the creation of stereomodels. The imagery was also assessed spectrally through fieldwork and spectroradiometric analysis, and for its Multiple View Angle (MVA) capability through visual and statistical analysis. Landscape archaeology requires a variety of data to be gathered from a large area, in an effective and inexpensive way. This study demonstrates an effective methodology for the deployment of CORONA and IKONOS imagery and raises a number of technical points of which the archaeological researcher community need to be aware of. Simultaneously, it identified certain limitations of the data and suggested solutions for the more effective exploitation of the strengths of CORONA imagery

    Digital Techniques for Documenting and Preserving Cultural Heritage

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    In this unique collection the authors present a wide range of interdisciplinary methods to study, document, and conserve material cultural heritage. The methods used serve as exemplars of best practice with a wide variety of cultural heritage objects having been recorded, examined, and visualised. The objects range in date, scale, materials, and state of preservation and so pose different research questions and challenges for digitization, conservation, and ontological representation of knowledge. Heritage science and specialist digital technologies are presented in a way approachable to non-scientists, while a separate technical section provides details of methods and techniques, alongside examples of notable applications of spatial and spectral documentation of material cultural heritage, with selected literature and identification of future research. This book is an outcome of interdisciplinary research and debates conducted by the participants of the COST Action TD1201, Colour and Space in Cultural Heritage, 2012–16 and is an Open Access publication available under a CC BY-NC-ND licence.https://scholarworks.wmich.edu/mip_arc_cdh/1000/thumbnail.jp

    VGC 2023 - Unveiling the dynamic Earth with digital methods: 5th Virtual Geoscience Conference: Book of Abstracts

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    Conference proceedings of the 5th Virtual Geoscience Conference, 21-22 September 2023, held in Dresden. The VGC is a multidisciplinary forum for researchers in geoscience, geomatics and related disciplines to share their latest developments and applications.:Short Courses 9 Workshops Stream 1 10 Workshop Stream 2 11 Workshop Stream 3 12 Session 1 – Point Cloud Processing: Workflows, Geometry & Semantics 14 Session 2 – Visualisation, communication & Teaching 27 Session 3 – Applying Machine Learning in Geosciences 36 Session 4 – Digital Outcrop Characterisation & Analysis 49 Session 5 – Airborne & Remote Mapping 58 Session 6 – Recent Developments in Geomorphic Process and Hazard Monitoring 69 Session 7 – Applications in Hydrology & Ecology 82 Poster Contributions 9

    Digital Techniques for Documenting and Preserving Cultural Heritage

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    This book presents interdisciplinary approaches to the examination and documentation of material cultural heritage, using non-invasive spatial and spectral optical technologies
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