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Initialization methods of convolutional neural networks for detection of image manipulations / Ivan Castillo Camacho (2021)
Titre : Initialization methods of convolutional neural networks for detection of image manipulations Titre original : Méthodes d'initialisation des réseaux de neurones convolutifs pour la détection des manipulations d'images Type de document : Thèse/HDR Auteurs : Ivan Castillo Camacho, Auteur ; Kai Wang, Directeur de thèse Editeur : Grenoble [France] : Université Grenoble Alpes Année de publication : 2021 Importance : 145 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse pour obtenir le grade de Docteur de l'Université Grenoble, spécialité : signal, image, paroles, télécomsLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] altération
[Termes IGN] apprentissage profond
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] covariance
[Termes IGN] détection d'anomalie
[Termes IGN] estompage
[Termes IGN] filtre passe-haut
[Termes IGN] flux de données
[Termes IGN] infraction
[Termes IGN] manipulation de données
[Termes IGN] qualité des données
[Termes IGN] retouche
[Termes IGN] varianceIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Fake images and videos have engulfed mass communication media. This is not something recent, manipulations and forgeries have occurred since the advent of photography itself. These alterations can go from innocent retouches in an attempt to make an image visually attractive to the spread of misleading information or even the use of false media in legal instances. Accordingly, the creation of methods that can help us assure the authenticity of an image presented as non-modified is of paramount importance. In this thesis, we aim at detecting image manipulation operations using deep learning techniques. We present three methods showing the progression of our work under one common objective, i.e, the design and test of Convolutional Neural Network (CNN) initialization methods for image forensic problems with a variance stability focus for the output of a CNN layer.First, we carry out an extensive review of the state of the art in deep-learning-based methods for image forensics. From this review we can confirm that the first layer of a CNN has big impact on the final performance. Specifically, the initialization used on the first-layer filters plays an important role that should be in line with the image forensic task in hand.As our first attempt to address this research problem, we propose a low-complexity initialization method for CNNs. Taking advantage of previous methods designed for the computer vision field, we extend the popular Xavier method to design a filter that would provide variance stability after a convolution operation. This method generates a set of random high-pass filters for the initialization of a CNN's first layer. These filters allow us to better identify forensic traces which usually lie towards the high-frequency part of the image.This first approach constitutes a good staring point of our work. However, a wrong assumption, largely utilized in the research community, was made. This is corrected in our second method where we follow a different data-dependent approach and take into consideration the real statistical properties of natural images. Accordingly, we propose a scaling method for first-layer filters which can cope well with different CNN initialization algorithms. The objective remains in keeping the stability of the variance of data flow in a CNN. We also present theoretical and experimental studies on the output variance for convolutional filter, which are the basis of our proposed data-dependent scaling.Next we describe a revisited version of our first proposal now with a corrected assumption on the statistics of natural images. More precisely, we propose an improved random high-pass initialization method which does not explicitly compute the statistics of input data. We believe that such a ``data-independent'' approach has higher flexibility and broader application range than our second method in situations where the computation of input statistics is not possible.Our proposed methods are tested over several image forensic problems and different CNN architectures.Finally, during all this thesis work we took part in a challenge competition of image forgery detection organized by the French National Research Agency and the French Directorate General of Armaments. We explain in the Appendix the objectives of the challenge along with a brief description of our work conducted for the competition. Note de contenu : 1- Introduction
2- Background knowledge and state of the art
3- Random high-pass initialization
4- Data-dependent initialization
5- Revisiting the random high-pass initialization
6- Conclusions and perspectivesNuméro de notice : 28437 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : signal, image, paroles, télécoms : Grenoble : 2021 DOI : sans En ligne : https://hal.science/tel-03346063/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98833
Titre : ITRF local tie survey at Malé – Maldives Type de document : Rapport Auteurs : Damien Pesce, Auteur Mention d'édition : version 1 Editeur : Saint-Mandé : Institut national de l'information géographique et forestière - IGN (2012-) Année de publication : 2021 Collection : Documents techniques du SGM num. 600 82 8691 Importance : 69 p. Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] point de liaison (géodésie)
[Termes IGN] rattachement
[Termes IGN] station DORIS
[Termes IGN] station GNSS
[Termes IGN] station permanenteRésumé : (auteur) The ITRF2020 realization (most recent frame of the International Terrestrial Reference System) computed by the ITRS product Centre (IGN Geodesy research team from IPGP) are the result of the reference frames combination from four space geodesy techniques (i.e. GNSS, DORIS, SLR and VLBI). One way to achieve one common frame consists in adding to the combination results from co-located sites local tie surveys. The Maldives Meteorological Service at the Male airport is equipped with a DORIS station and a GNSS station. This report describes the local tie survey carried out in September 2021 during the DORIS station installation on site and provides the associated results. Note de contenu : 1 Introduction
2 Co-location site description
3 Local tie survey description
4 Computation and data analysis
5 Results
6 AnnexesNuméro de notice : 14256 Affiliation des auteurs : IGN (2020- ) Thématique : POSITIONNEMENT Nature : Rapport nature-HAL : Rapport DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101376 Documents numériques
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ITRF local tie survey at Malé - pdf auteurAdobe Acrobat PDF Jahresbericht 2020 des Bundesamtes für Kartographie und Geodäsie / Bundesamt für Kartographie und Geodäsie (2021)
Titre : Jahresbericht 2020 des Bundesamtes für Kartographie und Geodäsie Titre original : Annual report 2020 Federal Agency for Cartography and Geodesy Type de document : Rapport Auteurs : Bundesamt für Kartographie und Geodäsie, Auteur Editeur : Francfort sur le Main : Bundesamt für Kartographie und Geodäsie Année de publication : 2021 Importance : 44 p. Format : 21 x 30 cm Langues : Allemand (ger) Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie
[Termes IGN] activité cartographique
[Termes IGN] activité géodésique
[Termes IGN] Allemagne
[Termes IGN] base de données localisées
[Termes IGN] géomatique
[Termes IGN] système de référence localNote de contenu : 1 Looking back: This was BKG´s year 2020
2 Facts and figures 2020
3 Geoportal 2.0 – new features, new design
4 A center of excellence for earth changes – coordinated by the BKG!
5 AGGO - Step by step to the flagship observatory
6 The new satellite positioning service for Germany
7 Our passion for collecting in your interest – Points of Interest
8 Where you can find us: Locations and contact detailsNuméro de notice : 17743 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Rapport d'activité DOI : sans En ligne : https://sg.geodatenzentrum.de/web_public/gdz/schriften/BKG-Jahresbericht-2020.pd [...] Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103112 Documents numériques
en open access
rapport 2020 - pdf éditeurAdobe Acrobat PDF
Titre : Model and reality: Connecting BIM and the built environment Type de document : Thèse/HDR Auteurs : Gustaf Uggla, Auteur Editeur : Stockholm : Royal Institute of Technology Année de publication : 2021 Importance : 79 p. Format : 21 x 30 cm Note générale : bibliographie
Doctoral Thesis in Geodesy and Geoinformatics, KTH Royal Institute of Technology, StockholmLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] apprentissage profond
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] données d'entrainement (apprentissage automatique)
[Termes IGN] données localisées 3D
[Termes IGN] format d'échange
[Termes IGN] format Industry foudation classes IFC
[Termes IGN] géoréférencement
[Termes IGN] métadonnées
[Termes IGN] modélisation 3D du bâti BIM
[Termes IGN] projection Universal Transverse Mercator
[Termes IGN] qualité des données
[Termes IGN] segmentation sémantique
[Termes IGN] semis de pointsIndex. décimale : THESE Thèses et HDR Résumé : (auteur) The adoption of building information modeling (BIM) in the architecture, engineering, and construction (AEC) industry is changing the way information regarding the built environment is created, stored, and exchanged. In short, documents are replaced with databases, processes are automated, and timelines become more circular with an emphasis on managing the life cycles of all manufactured objects. This has both direct and indirect consequences for the fields of geodesy and geographic information. Although geodesy and surveying have played a vital role in the construction process for a long time, new data standards and higher degrees of prefabrication and automation in the actual construction means that the topic of georeferencing must be revisited. In addition, using object oriented data structures means that semantic information must be inferred from geodata such as point clouds and images in order to adequately document existing assets. This thesis addresses the handling of 3D spatial information by analyzing different georeferencing methods and metadata used to describe the quality and characteristics of geodata. The outcomes include a recommendation for how the open BIM standard Industry Foundation Classes (IFC) could be extended to support more robust georeferencing, a suggestion that all standards and exchange formats used forthe built environment should include metadata for tolerance and uncertainty, and a framework that can describe characteristics of 3D spatial data that are not covered by conventional geographic metadata. On the semantic side, this thesis proposes an image-based method for identifying roadside objects in mobile laser scanning (MLS) point clouds, and it also explores the possibilities to train neural networks for point cloud segmentation by creating training data from 3D mesh models used in infrastructure design. Overall, the thesis describes the connection between model and reality, the importance of geodesy and geodetic surveying in this context, and makes contributions to both the geometric and semantic aspects of modeling the built environment. Note de contenu : 1- Introduction
2- Basis of knowledge and methods
3- Results
4- Summary of papersNuméro de notice : 28668 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/IMAGERIE Nature : Thèse étrangère Note de thèse : PhD Thesis : Geodesy and Geoinformatics : KTH, Stockholm : 2021 DOI : sans En ligne : http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-294087 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99878 Model based signal processing techniques for nonconventional optical imaging systems / Daniele Picone (2021)
Titre : Model based signal processing techniques for nonconventional optical imaging systems Type de document : Thèse/HDR Auteurs : Daniele Picone, Auteur ; Mauro Dalla Mura, Directeur de thèse Editeur : Grenoble [France] : Université Grenoble Alpes Année de publication : 2021 Importance : 364 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse pour obtenir le grade de Docteur de l'Université Grenoble Alpes, spécialité : Signal Image Parole TélécomsLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] acquisition comprimée
[Termes IGN] fusion d'images
[Termes IGN] image hyperspectrale
[Termes IGN] inférence statistique
[Termes IGN] interférométrie
[Termes IGN] méthode du maximum de vraisemblance (estimation)
[Termes IGN] mosaïque d'images
[Termes IGN] pouvoir de résolution géométrique
[Termes IGN] pouvoir de résolution spectrale
[Termes IGN] problème inverse
[Termes IGN] reconstruction d'image
[Termes IGN] régression non linéaire
[Termes IGN] spectromètre imageur
[Termes IGN] traitement du signalIndex. décimale : THESE Thèses et HDR Résumé : (auteur) There is an increasing demand for images with higher spectral and spatial resolution for applications in several domains such as health, environment, quality checking and natural disasters monitoring. Hyperspectral imagery provides the necessary spectral diversity to recover the composition of materials on site for applications such as the detection of fires, anomalies, chemical agents, targets and changes in the scene.The requirement for cheaper and more compact devices (e.g. to be embarked on low cost satellites and airborne platform) which are capable of capturing this information has led to the development of nonconventional innovative design concepts to overcome the technological limitations of traditional cameras. Data acquired by such novel imaging devices following the computational imaging paradigm are typically not readily exploitable for the final application. A computational phase is hence needed for extracting useful information from the raw acquisitions.This thesis addresses this issue by setting up an inversion problem. The general approach is to characterize the data fidelity term with a physical model, describing the underlying optical transformations performed by the device. The challenge is then shifted on the regularization step to properly characterizes the features of the quantities of interest and improve the accuracy of the estimation, which can be tackled with variational techniques.The analysis is applied to two novel concepts for nonconventional optical devices. The first one is a novel compressed acquisition imaging system based on color filter arrays, which embeds information from sensors with different spatial and spectral characteristics into a single mosaiced product. As opposed to existing compressed sensing based devices, the goal is not to recover the original uncompressed multiresolution sources, but instead to directly recover a synthetic fused image with both high spatial and spectral resolution.The proposed solution relies on the total variation regularization and is the subject of a detailed analysis, comparing its compressive power with straightforward software alternatives, evaluating its performances as the amount of channels changes, and validating its efficiency in comparison to state of the art methods when applied to classical fusion or mosaicing algorithms separately.The second class of devices is based on the ImSPOC patent, a design concept for a low finesse snapshot imaging spectrometer based on the interferometry of Fabry-Pérot. Its ideal behaviour follows the principle of the Fourier Transform Spectroscopy, as its acquisition can be interpreted as a sampled version of an interferogram, arranged across different sub-images distributed on the same focal plane.After defining a physical model based on optical geometry, its validity is evaluated over real acquisitions by setting up a Bayesian inference problem to determine its parameters, with approaches based on maximum likelihood estimators, regular-grid searches and nonlinear regression.A variety of preliminary tests are then carried out on the inversion method, with approaches based on singular value decomposition and sparse-inducing regularizers, accompanied by a analysis of their robustness to model mismatches. Note de contenu : 1- Introduction
2- Inverse problems theory
3- Signal processing of multimodal data
4- Joint fusion and demosaicing of compressed multiresolution acquisitions
5- Optics foundations for the ImSPOC acquisition system
6- Data processing pipeline of ImSPOC acquisitions
7- ConclusionsNuméro de notice : 28691 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Signal Image Parole Télécoms : Grenoble : 2021 Organisme de stage : GIPSA-lab DOI : sans En ligne : https://hal.science/tel-03596486v1 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100170 Modeling multifrequency GPS multipath fading in land vehicle environments / Vicente Carvalho Lima Filho in GPS solutions, vol 25 n° 1 (January 2021)PermalinkOptimisations cartographiques pour la gestion des crises et des risques majeurs : le cas de la cartographie des dommages post-catastrophes / Thomas Candela (2021)PermalinkLe parallèle des Pyrénées / Yves Maugard (2021)PermalinkPerformance of a solution of the direct geodetic problem by Taylor series of Cartesian coordinates / Christian Marx in Journal of geodetic science, vol 11 n° 1 (January 2021)PermalinkPositional uncertainty of network RTK observations in a modern datum / T. Bernstein in Journal of geodetic science, vol 11 n° 1 (January 2021)PermalinkPermalinkProjet ROYMAGE : une horloge optique transportable pour des applications géodésiques et géophysiques [diaporama] / Guillaume Lion (2021)PermalinkQuantification probabiliste des taux de déformation crustale par inversion bayésienne de données GPS / Colin Pagani (2021)PermalinkRapport d'activité 2020 de l'Institut National de l'Information Géographique et Forestière IGN, 1. Activité / Institut national de l'information géographique et forestière (2012 -) (2021)PermalinkRemote sensing and GIS / Basudeb Bhatta (2021)PermalinkPermalinkPermalinkROYMAGE Project: a transportable clock for geodetic and geophysical applications / Guillaume Lion (2021)PermalinkPermalinkSensitivity of segmentation of GNSS IWV time series and trend estimates to data properties / Khanh Ninh Nguyen (2021)PermalinkStatistical analysis of vertical land motions and sea level measurements at the coast / Kevin Gobron (2021)PermalinkPermalinkSub-daily polar motion from GPS, GLONASS, and Galileo / Radoslaw Zajdel in Journal of geodesy, vol 95 n° 1 (January 2021)PermalinkThe influence of sea-level changes on geodetic datums along the east coast of China / Yang Liu in Marine geodesy, vol 44 n° 1 (January 2021)PermalinkUnderstanding the geodetic signature of large aquifer systems: Example of the Ozark Plateaus in Central United States / Stacy Larochelle (2021)Permalink