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3D object detection using lidar point clouds and 2D image object detection / Topi Miekkala (2021)  

Public Titre : 3D object detection using lidar point clouds and 2D image object detection Type de document : Mémoire Auteurs : Topi Miekkala, Auteur Editeur : Tampere [Finlande] : Tampere University Année de publication : 2021 Importance : 67 p. Format : 21 x 30 cm Note générale : bibliographie Master of Science Thesis, Automation Engineering Langues : Français (fre) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] apprentissage profond [Termes IGN] détection d'objet [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] fusion de données [Termes IGN] image 2D [Termes IGN] navigation autonome [Termes IGN] objet 3D [Termes IGN] piéton [Termes IGN] point d'intérêt [Termes IGN] segmentation [Termes IGN] semis de points [Termes IGN] temps réel [Termes IGN] vision par ordinateur Résumé : (auteur) This master thesis is about the environmental sensing of an automated vehicle, and its ability to recognize objects of interest such as other road users including pedestrians and other vehicles. Automated driving is a popular and growing field of research, and the continuous increase in the demand of self-driving vehicles requires manufacturers to constantly improve the safety and environmental sensing capabilities of their vehicles. Deep learning neural networks and sensor data fusion are significant tools in the development of detection algorithms of automated vehicles. This thesis presents a method combining neural networks and sensor data fusion to implement 3D object detection into a self-driving car. The method uses an onboard camera sensor and a state of the art 2D image object detector YOLO v4, combining its detections with the data of a lidar sensor, which produces dense point clouds of its environment. These point clouds can be used to estimate distances and locations of surrounding targets. Using inter-sensor calibration between the camera and the lidar, the 3D points outputted by the lidar can be projected on a 2D image, therefore allowing the 3D location estimation of 2D objects detected in an image. The thesis first presents the research questions and the theoretical methods used to implement the algorithm. Some background on automated driving is also presented, followed by the specific research environment and vehicle used in this thesis. The thesis also presents the software implementations and vehicle system integration steps needed to implement everything into a self-driving car to achieve a real-time 3D object detection system. The results of this thesis show that using sensor data fusion, such a system can be integrated fully into a self-driving vehicle, and the processing times of the algorithm can be kept at a real-time rate. Note de contenu : 1- Introduction 2- Methods for sensor data and object detection 3- Autonomous driving and environmental sensing 4- Experiments 5- Evaluation 6- Conclusion Numéro de notice : 28594 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Mémoire masters divers En ligne : https://trepo.tuni.fi/handle/10024/132285 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99323

Geometric computer vision: omnidirectional visual and remotely sensed data analysis / Pouria Babahajiani (2021)  

Public Titre : Geometric computer vision: omnidirectional visual and remotely sensed data analysis Type de document : Thèse/HDR Auteurs : Pouria Babahajiani, Auteur ; Moncef Gabbouj, Directeur de thèse Editeur : Tampere [Finlande] : Tampere University Année de publication : 2021 Importance : 147 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-952-03-1979-3 Note générale : bibliographie Accademic Dissertation, Tampere University, Faculty of Information Technology and Communication Sciences Finland Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] apprentissage automatique [Termes IGN] chaîne de traitement [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] effet de profondeur cinétique [Termes IGN] espace public [Termes IGN] extraction de traits caractéristiques [Termes IGN] image panoramique [Termes IGN] image Streetview [Termes IGN] image terrestre [Termes IGN] modèle 3D de l'espace urbain [Termes IGN] modèle sémantique de données [Termes IGN] réalité virtuelle [Termes IGN] scène urbaine [Termes IGN] segmentation sémantique [Termes IGN] semis de points [Termes IGN] vision par ordinateur [Termes IGN] zone urbaine Index. décimale : THESE Thèses et HDR Résumé : (auteur) Information about the surrounding environment perceived by the human eye is one of the most important cues enabled by sight. The scientific community has put a great effort throughout time to develop methods for scene acquisition and scene understanding using computer vision techniques. The goal of this thesis is to study geometry in computer vision and its applications. In computer vision, geometry describes the topological structure of the environment. Specifically, it concerns measures such as shape, volume, depth, pose, disparity, motion, and optical flow, all of which are essential cues in scene acquisition and understanding. This thesis focuses on two primary objectives. The first is to assess the feasibility of creating semantic models of urban areas and public spaces using geometrical features coming from LiDAR sensors. The second objective is to develop a practical Virtual Reality (VR) video representation that supports 6-Degrees-of-Freedom (DoF) head motion parallax using geometric computer vision and machine learning. The thesis’s first contribution is the proposal of semantic segmentation of the 3D LiDAR point cloud and its applications. The ever-growing demand for reliable mapping data, especially in urban environments, has motivated mobile mapping systems’ development. These systems acquire high precision data and, in particular 3D LiDAR point clouds and optical images. A large amount of data and their diversity make data processing a complex task. A complete urban map data processing pipeline has been developed, which annotates 3D LiDAR points with semantic labels. The proposed method is made efficient by combining fast rule-based processing for building and street surface segmentation and super-voxel-based feature extraction and classification for the remaining map elements (cars, pedestrians, trees, and traffic signs). Based on the experiments, the rule-based processing stage provides substantial improvement not only in computational time but also in classification accuracy. Furthermore, two back ends are developed for semantically labeled data that exemplify two important applications: (1) 3D high definition urban map that reconstructs a realistic 3D model using input labeled point cloud, and (2) semantic segmentation of 2D street view images. The second contribution of the thesis is the development of a practical, fast, and robust method to create high-resolution Depth-Augmented Stereo Panoramas (DASP) from a 360-degree VR camera. A novel and complete optical flow-based pipeline is developed, which provides stereo 360-views of a real-world scene with DASP. The system consists of a texture and depth panorama for each eye. A bi-directional flow estimation network is explicitly designed for stitching and stereo depth estimation, which yields state-of-the-art results with a limited run-time budget. The proposed architecture explicitly leverages geometry by getting both optical flow ground-truths. Building architectures that use this knowledge simplifies the learning problem. Moreover, a 6-DoF testbed for immersive content quality assessment is proposed. Modern machine learning techniques have been used to design the proposed architectures addressing many core computer vision problems by exploiting the enriched information coming from 3D scene structures. The architectures proposed in this thesis are practical systems that impact today’s technologies, including autonomous vehicles, virtual reality, augmented reality, robots, and smart-city infrastructures. Note de contenu : 1- Introduction 2- Geometry in Computer Vision 3- Contributions 4- Conclusion Numéro de notice : 28323 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère Note de thèse : PhD Thesis : Computing and Electrical Engineering : Tempere, Finland : 2021 DOI : sans En ligne : https://trepo.tuni.fi/handle/10024/131379 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98342

Geospatial analysis of the spreading of COVID-19 In the United States / Otto Heimonen (2021)  

Public Titre : Geospatial analysis of the spreading of COVID-19 In the United States Type de document : Mémoire Auteurs : Otto Heimonen, Auteur Editeur : Tampere [Finlande] : Tampere University Année de publication : 2021 Importance : 67 p. Format : 21 x 30 cm Note générale : bibliographie Master’s Degree Programme in Computational Big Data Analytics Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] autocorrélation spatiale [Termes IGN] champ aléatoire conditionnel [Termes IGN] épidémie [Termes IGN] estimation bayesienne [Termes IGN] Etats-Unis [Termes IGN] maladie infectieuse [Termes IGN] méthode de Monte-Carlo par chaînes de Markov [Termes IGN] méthode du maximum de vraisemblance (estimation) [Termes IGN] modèle de simulation Résumé : (auteur) The COVID-19 pandemic has been a big threat to public health and there is an increasing need for efficient modelling of pathogens, predicting the daily infection rates to reduce the spread of COVID-19. The Moran’s and Geary’s statistics showed significant spatial autocorrelation in the infection counts for the US COVID-19 data. Spatial regression using the simultaneous autoregression (SAR) and conditional autoregression (CAR) models indicate clear association between the confirmed cases and the number of population and the population density in both national county and state specific analyses. The SAR model provided a better model fit with the low AIC value, leaving no significant autocorrelation for the residuals. The approximate Bayesian computation (ABC) methods were used to provide a flexible posterior distribution of the infection rate for COVID-19 based on the first 100 days of the pandemic. Three different simulation methods such as ABC-Rejection, ABC-Markov Chain Monte Carlo (MCMC) and ABC-Sequential Monte Carlo (SMC) were employed and compared. These algorithms seem to give reasonable posterior estimates for the average daily infections when the likelihood calculations for the spread of a harmful pathogen become complex, or intractable entirely. The posterior distributions of ABC-MCMC and ABC-SMC provided plausible estimations covering all of the observed infection rates at different time points. Note de contenu : 1- Introduction 2- Methods 3- Empirical data analysis 4- Discussion Numéro de notice : 28455 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/MATHEMATIQUE Nature : Mémoire masters divers DOI : sans En ligne : https://trepo.tuni.fi/handle/10024/134567 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99025