Publications of Florent Poux
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See detailAutomatic extraction and management of semantics within point cloud data
Poux, Florent ULiege

Conference (2020, May 28)

In the context of 3D point clouds, reality capture and artificial intelligence, the presentation covers exciting research potential of point clouds, semantics and unsupervised frameworks.

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See detailThe Smart Point Cloud Model: Integration of point intelligence
Poux, Florent ULiege

Conference (2019, December 05)

Point cloud acquisition and processing workflows are usually application-dependent following a classic progression from data gathering to deliverable creation. While the collection step may be specific to ... [more ▼]

Point cloud acquisition and processing workflows are usually application-dependent following a classic progression from data gathering to deliverable creation. While the collection step may be specific to the sensor at hands, point-cloud-as-a-deliverable upsurges, becoming one de-facto choice for many industries. This task-oriented scenario mainly considers these as a spatial reference – which is used by experts to create other deliverables – thus being a project’s closest link to reality. It brings accurate real-world information which could allow decision-making based on digital-reality instead of interpreted or not up-to-date information. However, there are several considerations to address for a suitable integration. Point clouds are often very large depending on how much data is collected – usually in the realms of Gigabytes, if not Terabytes – and are destined to be archived as a reusable support to create new type of data and products. This can lead to a dead-end with exponential storage needs, incompatibility between outputs, loss of information and complicated collaboration. These practices also show limited to no attempt to generalize a framework which could in turn play as a common ground for further interoperability and generalization. This lack is counterproductive and could lead in term to a chaotic data repartition among actors and worsen the dependency to several outsourced service, each aiming an application independently. This primarily emphasize a strong need to study interoperable scenarios in which one point cloud could be used by many users from different domains, each having a different need (E.g. the object of interest can be a building or only the roof of this building). This will in turn introduce new constraints at the acquisition level to define the needed exhaustivity of the 3D representation for use with reasoning engines. Of course, this serialize additional challenges for interconnecting processes and insuring a compatibility with the different sources, volumes and other data-driven parameters. Secondly, robotics research has made a leap forward providing autonomous 3D recording systems, where we obtain a 3D point cloud of environments with no human intervention. Of course, following this idea to develop autonomous surveying demands that the data can be used for decision-making. The collected point cloud without context does not permit to take a valid decision, and the knowledge of experts is needed to extract the necessary information and to creates a viable data support for decision-making. Automating this process for fully autonomous cognitive decision systems is very tempting but poses many challenges mainly link to Knowledge Extraction (KE), Knowledge Integration (KI) and Knowledge Representation (KR) from point cloud. Therefore, point cloud structuration must be specifically designed to allow the computer to use it as a base for information extraction using reasoning and agent-based systems. Interoperable approaches which permits several actors to leverage one common information system (E.g. Facility Management 4.0) based on a digital twin is a great exploration motor. In this continuum, the presentation feeds a broader reflexion to go from a human-centered process to an autonomous workflow which highlights a need to improve automation, data management and interaction to speed-up inference processes, crucial to the development of point clouds in 3D capture workflows. The presentation primarily aims at providing all the necessary information for the development of an infrastructure: The Smart Point Cloud (SPC). It permits to handle point cloud data, manage heterogeneity, process and group points that retain a relationship regarding a specific domain ontology that allow to query and reason for decision-making tools including smart modelling. The resulting implementation of the SPC is based on new meta-models that permit to structure the information (3D geometry and semantics) and leverage available knowledge for accessing decision-making support tools and reasoning capabilities. At the frontier between a point cloud GIS system and a spatial infrastructure for agent-based decision support systems, its flexibility allows to evolve with future developments using artificial intelligence and new machine learning approaches. The proposed modular infrastructure includes Knowledge Discovery processes with Knowledge Integration and Knowledge Representation as ontologies, proving efficient context-specific adaptation. [less ▲]

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See detailSemantic enrichment of point cloud by automatic extraction and enhancement of 360° panoramas
Tabkha, A.; Hajji, R.; Billen, Roland ULiege et al

in International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences (2019, November 29), XLII-2(W17), 355-362

The raw nature of point clouds is an important challenge for their direct exploitation in architecture, engineering and construction applications. Particularly, their lack of semantics hinders their ... [more ▼]

The raw nature of point clouds is an important challenge for their direct exploitation in architecture, engineering and construction applications. Particularly, their lack of semantics hinders their utility for automatic workflows (Poux, 2019). In addition, the volume and the irregularity of the structure of point clouds makes it difficult to directly and automatically classify datasets efficiently, especially when compared to the state-of-the art 2D raster classification. Recently, with the advances in deep learning models such as convolutional neural networks (CNNs) , the performance of image-based classification of remote sensing scenes has improved considerably (Chen et al., 2018; Cheng et al., 2017). In this research, we examine a simple and innovative approach that represent large 3D point clouds through multiple 2D projections to leverage learning approaches based on 2D images. In other words, the approach in this study proposes an automatic process for extracting 360° panoramas, enhancing these to be able to leverage raster data to obtain domain-base semantic enrichment possibilities. Indeed, it is very important to obtain a rigorous characterization for use in the classification of a point cloud. Especially because there is a very large variety of 3D point cloud domain applications. In order to test the adequacy of the method and its potential for generalization, several tests were performed on different datasets. The developed semantic augmentation algorithm uses only the attributes X, Y, Z and camera positions as inputs. [less ▲]

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See detailCLASSIFICATION AND INTEGRATION OF MASSIVE 3D POINTS CLOUDS IN A VIRTUAL REALITY (VR) ENVIRONMENT
Kharroubi, Abderrazaq; Hajji, Rafika; Billen, Roland ULiege et al

in International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences (2019, November 29), XLII-2(W17), 165-171

With the increasing volume of 3D applications using immersive technologies such as virtual, augmented and mixed reality, it is very interesting to create better ways to integrate unstructured 3D data such ... [more ▼]

With the increasing volume of 3D applications using immersive technologies such as virtual, augmented and mixed reality, it is very interesting to create better ways to integrate unstructured 3D data such as point clouds as a source of data. Indeed, this can lead to an efficient workflow from 3D capture to 3D immersive environment creation without the need to derive 3D model, and lengthy optimization pipelines. In this paper, the main focus is on the direct classification and integration of massive 3D point clouds in a virtual reality (VR) environment. The emphasis is put on leveraging open-source frameworks for an easy replication of the findings. First, we develop a semi-automatic segmentation approach to provide semantic descriptors (mainly classes) to groups of points. We then build an octree data structure leveraged through out-of-core algorithms to load in real time and continuously only the points that are in the VR user's field of view. Then, we provide an open-source solution using Unity with a user interface for VR point cloud interaction and visualisation. Finally, we provide a full semantic VR data integration enhanced through developed shaders for future spatio-semantic queries. We tested our approach on several datasets of which a point cloud composed of 2.3 billion points, representing the heritage site of the castle of Jehay (Belgium). The results underline the efficiency and performance of the solution for visualizing classifieds massive point clouds in virtual environments with more than 100 frame per second. [less ▲]

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See detail3D Point Clouds on the Web: A cost-efficient support for decision making
Poux, Florent ULiege

Conference (2019, October 29)

This paper presents a 3D web platform and the main reflexion that initiated the project: Flyvast. This real-time 3D media permits to manage, Point Cloud Data, Raster Data and vector Data. Moreover, it ... [more ▼]

This paper presents a 3D web platform and the main reflexion that initiated the project: Flyvast. This real-time 3D media permits to manage, Point Cloud Data, Raster Data and vector Data. Moreover, it permits to work with full resolution data organised in projects. The users have the ability to collaborate, annotate, segment, classify and export any or part of datasets, as well a using it as a direct support for additional services, including external DBMS and GIS systems. The full structure is based by considering point clouds as the main spatial backbone of the different collaborations, demanding massive data structuration and indexing for a real time use over 30 fps on the web. [less ▲]

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See detailSmart point clouds : Les dernières avancées en termes de structuration des nuages de points.
Poux, Florent ULiege; Billen, Roland ULiege

Conference given outside the academic context (2019)

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See detailA Smart Point Cloud Infrastructure for intelligent environments
Poux, Florent ULiege; Billen, Roland ULiege

in Lindenbergh, Roderik; Riveiro-Rodríguez, Belén (Eds.) Laser scanning: an emerging technology in structural engineering (2019)

3D point cloud data describes our physical world spatially. Knowledge discovery processes including semantic segmentation and classification are a great way to complement this information by leveraging ... [more ▼]

3D point cloud data describes our physical world spatially. Knowledge discovery processes including semantic segmentation and classification are a great way to complement this information by leveraging analytic or domain knowledge to extract semantics. Combining efficiently this information is an opening on intelligent environments and deep automation. This chapter provides a conceptual data model to structure 3D point data, semantics and topology proficiently. It aims at creating an interactive clone of the real world usable by cognitive decision systems. A multi-modal infrastructure integrating this data model is presented that includes knowledge extraction, knowledge integration and knowledge representation for automatic agent-based decision-making over enriched point cloud data. A knowledge base processing with ontologies is provided for extended interoperability. [less ▲]

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See detailThe Smart Point Cloud: Structuring 3D intelligent point data
Poux, Florent ULiege

Doctoral thesis (2019)

Discrete spatial datasets known as point clouds often lay the groundwork for decision-making applications. E.g., we can use such data as a reference for autonomous cars and robot’s navigation, as a layer ... [more ▼]

Discrete spatial datasets known as point clouds often lay the groundwork for decision-making applications. E.g., we can use such data as a reference for autonomous cars and robot’s navigation, as a layer for floor-plan’s creation and building’s construction, as a digital asset for environment modelling and incident prediction... Applications are numerous, and potentially increasing if we consider point clouds as digital reality assets. Yet, this expansion faces technical limitations mainly from the lack of semantic information within point ensembles. Connecting knowledge sources is still a very manual and time-consuming process suffering from error-prone human interpretation. This highlights a strong need for domain-related data analysis to create a coherent and structured information. The thesis clearly tries to solve automation problematics in point cloud processing to create intelligent environments, i.e. virtual copies that can be used/integrated in fully autonomous reasoning services. We tackle point cloud questions associated with knowledge extraction – particularly segmentation and classification – structuration, visualisation and interaction with cognitive decision systems. We propose to connect both point cloud properties and formalized knowledge to rapidly extract pertinent information using domain-centered graphs. The dissertation delivers the concept of a Smart Point Cloud (SPC) Infrastructure which serves as an interoperable and modular architecture for a unified processing. It permits an easy integration to existing workflows and a multi-domain specialization through device knowledge, analytic knowledge or domain knowledge. Concepts, algorithms, code and materials are given to replicate findings and extend current applications. [less ▲]

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See detailVoxel-Based 3D Point Cloud Semantic Segmentation: Unsupervised Geometric and Relationship Featuring vs Deep Learning Methods
Poux, Florent ULiege; Billen, Roland ULiege

in ISPRS International Journal of Geo-Information (2019), 8(5), 213

Automation in point cloud data processing is central in knowledge discovery within decision-making systems. The definition of relevant features is often key for segmentation and classification, with ... [more ▼]

Automation in point cloud data processing is central in knowledge discovery within decision-making systems. The definition of relevant features is often key for segmentation and classification, with automated workflows presenting the main challenges. In this paper, we propose a voxel-based feature engineering that better characterize point clusters and provide strong support to supervised or unsupervised classification. We provide different feature generalization levels to permit interoperable frameworks. First, we recommend a shape-based feature set (SF1) that only leverages the raw X, Y, Z attributes of any point cloud. Afterwards, we derive relationship and topology between voxel entities to obtain a three-dimensional (3D) structural connectivity feature set (SF2). Finally, we provide a knowledge-based decision tree to permit infrastructure-related classification. We study SF1/SF2 synergy on a new semantic segmentation framework for the constitution of a higher semantic representation of point clouds in relevant clusters. Finally, we benchmark the approach against novel and best-performing deep-learning methods while using the full S3DIS dataset. We highlight good performances, easy-integration, and high F1-score (> 85%) for planar-dominant classes that are comparable to state-of-the-art deep learning. [less ▲]

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See detail3D Viewpoint Management and Navigation in Urban Planning: Application to the Exploratory Phase
Neuville, Romain ULiege; Pouliot, Jacynthe; Poux, Florent ULiege et al

in Remote Sensing (2019), 11(3), 236

3D geovisualization is essential in urban planning as it assists the analysis of geospatial data and decision making in the design and development of land use and built environment. However, we noted that ... [more ▼]

3D geovisualization is essential in urban planning as it assists the analysis of geospatial data and decision making in the design and development of land use and built environment. However, we noted that 3D geospatial models are commonly visualized arbitrarily as current 3D viewers often lack of design instructions to assist end users. This is especially the case for the occlusion management in most 3D environments where the high density and diversity of 3D data to be displayed require efficient visualization techniques for extracting all the geoinformation. In this paper, we propose a theoretical and operational solution to manage occlusion by automatically computing best viewpoints. Based on user’s parameters, a viewpoint management algorithm initially calculates optimal camera settings for visualizing a set of 3D objects of interest through parallel projections. Precomputed points of view are then integrated into a flythrough creation algorithm for producing an automatic navigation within the 3D geospatial model. The algorithm’s usability is illustrated within the scope of a fictive exploratory phase for the public transport services access in the European quarter of Brussels. Eventually, the proposed algorithms may also assist additional urban planning phases in achieving their purposes. [less ▲]

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See detail3D Point Cloud Semantic Modelling: Integrated Framework for Indoor Spaces and Furniture
Poux, Florent ULiege; Neuville, Romain ULiege; Nys, Gilles-Antoine ULiege et al

in Remote Sensing (2018), 10(9), 1412

3D models derived from point clouds are useful in various shapes to optimize the trade-off between precision and geometric complexity. They are defined at different granularity levels according to each ... [more ▼]

3D models derived from point clouds are useful in various shapes to optimize the trade-off between precision and geometric complexity. They are defined at different granularity levels according to each indoor situation. In this article, we present an integrated 3D semantic reconstruction framework that leverages segmented point cloud data and domain ontologies. Our approach follows a part-to-whole conception which models a point cloud in parametric elements usable per instance and aggregated to obtain a global 3D model. We first extract analytic features, object relationships and contextual information to permit better object characterization. Then, we propose a multi-representation modelling mechanism augmented by automatic recognition and fitting from the 3D library ModelNet10 to provide the best candidates for several 3D scans of furniture. Finally, we combine every element to obtain a consistent indoor hybrid 3D model. The method allows a wide range of applications from interior navigation to virtual stores. [less ▲]

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See detailLa transition numérique dans le domaine du patrimoine bâti: un retour d'expériences
Billen, Roland ULiege; Jonlet, Benoît ULiege; Luczfalvy Jancsó, Andrea ULiege et al

in Bulletin de la commission royale des monuments, sites et fouilles - Tome 30 (2018)

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See detailSmart Point Clouds for information modelling: application in Cultural Heritage
Poux, Florent ULiege; Hallot, Pierre ULiege

Conference (2018, June 01)

Le travail présenté décrit un modèle interopérable pour la gestion des nuages de points volumineux tout en intégrant la sémantique. Les routines de traitement et les modèles de données actuels manquent de ... [more ▼]

Le travail présenté décrit un modèle interopérable pour la gestion des nuages de points volumineux tout en intégrant la sémantique. Les routines de traitement et les modèles de données actuels manquent de connaissances pour raisonner à partir de l’extraction d’information plutôt que de l’interprétation. Le modèle conceptuel de nuages de points intelligents développé permet d'apporter l'intelligence aux nuages de points via 3 méta-modèles connectés, tout en reliant les connaissances disponibles et les procédures de classification qui permettent l'injection sémantique.L'interopérabilité conduit l'adaptation du modèle à de nombreuses applications grâce à des ontologies de domaines spécialisés. Un premier prototype est implémenté dans la base de données Python et PostgreSQL et permet de combiner des concepts sémantiques et spatiaux pour des requêtes hybrides de base sur différents nuages de points. Une application du modèle est proposée dans la détermination de tesselles de la voute de l’oratoire carolorégien de Germigny-des-prés. Les tesselles sont identifiées de façon automatique sur une interaction entre 18 caractéristiques, dont les données biaisées du capteur, chaque tesselles dans le nuage de points à haute densité des mosaïques complexes capturées en 3D. Les connaissances sont ensuite utilisées pour classer chaque tesselles en fonction de leur taille, de leur surface, de leur forme, de leurs propriétés matérielles et de la classe de leur voisins. La méthode de détection et d'enrichissement sémantique montre des résultats prometteurs avec 94 % de sémantisation correcte, première étape vers la création d'un nuage de point archéologique intelligent. [less ▲]

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See detailA Formalized 3D Geovisualization Illustrated to Selectivity Purpose of Virtual 3D City Model
Neuville, Romain ULiege; Pouliot, Jacynthe; Poux, Florent ULiege et al

in ISPRS International Journal of Geo-Information (2018), 7(5),

Virtual 3D city models act as valuable central information hubs supporting many aspects of cities, from management to planning and simulation. However, we noted that 3D city models are still ... [more ▼]

Virtual 3D city models act as valuable central information hubs supporting many aspects of cities, from management to planning and simulation. However, we noted that 3D city models are still underexploited and believe that this is partly due to inefficient visual communication channels across 3D model producers and the end-user. With the development of a formalized 3D geovisualization approach, this paper aims to support and make the visual identification and recognition of specific objects in the 3D models more efficient and useful. The foundation of the proposed solution is a knowledge network of the visualization of 3D geospatial data that gathers and links mapping and rendering techniques. To formalize this knowledge base and make it usable as a decision-making system for the selection of styles, second-order logic is used. It provides a first set of efficient graphic design guidelines, avoiding the creation of graphical conflicts and thus improving visual communication. An interactive tool is implemented and lays the foundation for a suitable solution for assisting the visualization process of 3D geospatial models within CAD and GIS-oriented software. Ultimately, we propose an extension to OGC Symbology Encoding in order to provide suitable graphic design guidelines to web mapping services. [less ▲]

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See detailNumérisation 3D par lasergrammétrie et photogrammétrie: applications à la Réalité Virtuelle
Poux, Florent ULiege; Luczfalvy Jancsó, Andrea ULiege; Jonlet, Benoît ULiege et al

Conference (2018, March 08)

Alors que les copies virtuelles du monde réel ont tendance à être créées plus rapidement que jamais sous forme de nuages de points et produits dérivés, leur utilisation par tous les professionnels demande ... [more ▼]

Alors que les copies virtuelles du monde réel ont tendance à être créées plus rapidement que jamais sous forme de nuages de points et produits dérivés, leur utilisation par tous les professionnels demande de nouveaux outils pour faciliter la diffusion des connaissances. Les analyses numériques changent la manière dont les chercheurs, les archéologues et les conservateurs du patrimoine travaillent et collaborent pour combiner progressivement leur expertise grâce à une plate-forme commune. Néanmoins, l’adjonction d'information sémantique pour compléter les nuages de points est essentielle pour permettre une utilisation complète comme donnée de référence. Les concepts et les outils qui simplifient ce processus sont rares, ce qui complique la mise en commun des analyses. Différentes méthodes seront présentées permettant d'extraire des informations archéologiques aux nuages de points et créer une connexion avec les connaissances structurées sous forme d'ontologie. Les outils de communication et de visualisation 3D développés pour permettre plusieurs interactions seront illustrées sur le château de Jehay. Un partenariat a été établi entre cette association et l’Unité de Géomatique de l’Université de Liège. Il porte non seulement sur l’acquisition de données 3D mais aussi sur l’accompagnement de l’association dans ses projets de recherches archéologiques, de réhabilitation du site et de valorisation. Plusieurs campagnes de mesures ont été réalisées à différents stades de la rénovation. De nouvelles missions sont prévues notamment par des étudiants de l’Université. Outre plusieurs vidéos promotionnelles et quelques produits dérivés utiles à la rénovation, une exploitation en réalité virtuelle retient pour le moment l’attention de nos développeurs. En effet, le Château étant actuellement en grande partie fermé au public, il est prévu cet été d’offrir sur le site des visites en réalité virtuelle basées sur des levés lasergrammétriques et photogrammétriques. À plus long terme, il est prévu d’établir un système d’information spatialisée dédié au Château ; les bases conceptuelles de ce système ont déjà été dressées lors d’une récente étude. [less ▲]

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See detailFusion de données lasergrammétriques/photogrammétriques et techniques d'extraction d'information archéologique sur base de nuage de points 3D
Poux, Florent ULiege; Billen, Roland ULiege; Hallot, Pierre ULiege et al

Conference (2018, March 08)

While virtual copies of the real world tend to be created faster than ever in the form of point clouds and derived products, their use by all professionals requires new tools to facilitate the ... [more ▼]

While virtual copies of the real world tend to be created faster than ever in the form of point clouds and derived products, their use by all professionals requires new tools to facilitate the dissemination of knowledge. Digital analyses are changing the way researchers, archaeologists and heritage curators work and collaborate to gradually combine their expertise through a common platform. Nevertheless, the addition of semantic information to complete the point clouds is essential to allow a complete use as reference data. There are few concepts and tools that simplify this process, making it difficult to share analyses. Different methods will be presented to extract archaeological information from the point clouds and create a connection with the structured knowledge in the form of ontology. Classification and structuring procedures for reasoning from the data will be discussed. These methodologies will be illustrated at the Germigny-des-prés (France) and Château de Jehay (Belgium) sites. The communication and 3D visualization tools developed to allow several interactions will also be presented. While the Germigny-des-prés site (France) is almost exclusively dedicated to research, the same is not true for the Jehay site. This exceptional site belongs to the Province of Liège and is managed by a non-profit association. A partnership has been established between this association and the Geomatics Unit of the University of Liège. It concerns not only the acquisition of 3D data but also the support of the association in its archaeological research, site rehabilitation and enhancement projects. Several measurement campaigns were carried out at different stages of the renovation. New missions are planned, notably by students from the University. In addition to several promotional videos and a few derivative products useful for renovation, a virtual reality operation is currently attracting the attention of our developers. Indeed, the Castle is currently largely closed to the public, it is planned this summer to offer virtual reality tours based on lasergrammetric and photogrammetric surveys. In the longer term, it is planned to establish a spatialized information system dedicated to the Castle; the conceptual bases of this system have already been established during a recent study. [less ▲]

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See detailCASTLE4D : The Castle of Franchimont (Theux, Province of Liège, Belgium)
Luczfalvy Jancsó, Andrea ULiege; Hoffsummer, Patrick ULiege; Billen, Roland ULiege et al

in Ettel, Peter; Flambard Héricher, Anne-Marie; O'Conor, Kieran (Eds.) Château Gaillard 28 - L'environnement du château (2018)

This paper presents the CASTLE4D project and its application to the castle of Franchimont (Theux, Province of Liège, Belgium). The combination of traditional archaeological methods and new technologies ... [more ▼]

This paper presents the CASTLE4D project and its application to the castle of Franchimont (Theux, Province of Liège, Belgium). The combination of traditional archaeological methods and new technologies (3D digitisation) will result in the development of an Archaeological Information System (AIS), based on Geographic Information systems (GIS). This AIS is going to gather all types of available documents for the study of this castle whilst organising them spatially and chronologically around the 3D model. This tool will then help to create a historic geovisualisation, which should modify its appearance according to the selected time period and the data linked to this phase. This way, the establishment and the verification of hypothesis is going to have a visual support (the three-dimensional digitisation) and a collection of the sources on which the different theories were elaborated on. [less ▲]

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See detailThe carolingian site of Germigny-des-Prés (Loiret, France), micro and macro-scales methods for the identification of a mosaic production.
Van Wersch, Line ULiege; Hocquet, François-Philippe ULiege; Strivay, David ULiege et al

Poster (2018)

The church of Germigny-des-Prés is one of the oldest in France. It holds the only early medieval mosaics preserved north of the Alps, ordered by Theodulph, close counselor of Charlemagne, at the beginning ... [more ▼]

The church of Germigny-des-Prés is one of the oldest in France. It holds the only early medieval mosaics preserved north of the Alps, ordered by Theodulph, close counselor of Charlemagne, at the beginning of the 9th century AD to decorate the oratory of his villa 1. Restored in the 19th century, it still conserved a part of the original material. These tesserae are a great opportunity to reach the glass from the early Middle Ages, period of change for glass production. Moreover, this site could have hold a mosaic workshop and it could be the first settlement of this type ever discovered 2. In situ, a macroscopic exam and pXRF analyses done on the tesserae from the vault and arches allow to distinguish original material and restored area. 15 glass samples were analysed using EMP-WDS and LA-ICP-MS in order to identify their materials and techniques as well as their origins. A 3D scan of the building makes possible to quantify accurately the materials, to manage the information and to view the results. Finally, ground penetrating radar prospections were done on the site in order to locate a potential workshop. The concentrations of lead, potassium and iron allow us to distinguish the early medieval tesserae from the new ones. Thanks to this, the original part of the mosaic can be precisely differentiated from the restoration of the 19th century that is vaster than previously thought. Still, the figures of the vault appear to be original. The analysed cubes show that some were re-used roman tesserae but the ones with gold and silver, the most numerous in the mosaic of the vault, come from an original production, specific to this site. Structures were found by prospections in different locations around the church and excavations will now take place in order to identify this remains and a potential workshop. Acknowledgements: to the council of Germigny-des-Prés and the DRAC Centre Val-de-Loire for the research authorizations. The missions were financed by the FRS-FNRS, The Comhaire prize of the foundation Roi Baudouin and by ARCHEA. 1 A. Freeman, P. Meyvaert, Gesta (2001), 125- 139. 2 L. James, E. Soproni, B. Bjornholt, in «Mosaics by numbers, (2013), 310-328. [less ▲]

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See detailRecherches récentes sur le site de Germigny-des-Prés (Loiret, France).
Van Wersch, Line ULiege; Hocquet, François-Philippe ULiege; Strivay, David ULiege et al

Conference (2018)

Restauré au XIXe siècle, l'église de Germigny-des-Prés est actuellement la seule au nord des Alpes à abriter des mosaïques alto-médiévales. L’édifice de culte, bâti au début du IXe siècle, faisait partie ... [more ▼]

Restauré au XIXe siècle, l'église de Germigny-des-Prés est actuellement la seule au nord des Alpes à abriter des mosaïques alto-médiévales. L’édifice de culte, bâti au début du IXe siècle, faisait partie de la villa de Théodulphe, proche conseiller de Charlemagne, abbé de Fleury et évêque d’Orléans. Ce site est donc exceptionnel à plus d’un titre. D’une part, l’église est une des plus anciennes de France et, en dépit de restaurations, elle reste un témoignage singulier de l’architecture religieuse alto-médiévale. D’autre part, ses mosaïques nous permettent d’aborder ce type de décoration et plus largement le verre, matériaux rares pour cet époque. Enfin, le site devrait receler les vestiges d’une villa carolingienne dont la réalité matérielle pose encore de nombreuses interrogations. Depuis trois ans, en collaboration avec une équipe internationale, des recherches utilisant des méthodes diverses ont été entreprises. Les mosaïques ont fait l’objet d’un premier examen macroscopique et d’analyses pXRF In situ pour distinguer les parties originales de la restauration du XIXe siècle. 15 échantillons de verre ont ensuite été analysés en EMP-WDS et LA-ICP-MS afin d'identifier leurs matériaux, recettes et provenances. Malgré la restauration plus vaste qu'on ne le pensait auparavant, des parties originales subsistent sur la voûte orientale. Si, des tesselles colorées antiques ont été réutilisés, les cubes couverts d’or et d’argent proviennent d'une production originale. Aucune correspondance n’existant dans le monde italien et byzantin, ils pourraient être issus d’une production spécifique, peut-être régionale. Des prospections géoradars ont été effectuées sur le site afin de localiser de potentiels vestiges alto-médiévaux. Elles ont mis en évidence l’existence de structures en différents emplacements. A l’intérieur du bâtiment, elles ont identifié l’abside occidentale confirmant la restitution du plan original proposé en 1930. A l’extérieur, elles ont permis de détecter les zones sur lesquelles devraient se concentrer les recherches archéologiques. Enfin, un scan 3D a permis un relevé précis du bâtiment. Il sera utilisé pour la gestion de l'information et la visualiser des résultats des recherches que nous espérons poursuivre sur le site de Germigny-des-Prés. [less ▲]

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