GCH 2020 - Eurographics Workshop on Graphics and Cultural Heritage

Permanent URI for this collection

Online Event, November 18 – 19, 2020
3D Data Management and Visualization
Semi-automated Annotation of Repetitive Ornaments on 3D Painted Pottery Surfaces
Stefan Lengauer, Alexander Komar, Stephan Karl, Elisabeth Trinkl, Ivan Sipiran, Tobias Schreck, and Reinhold Preiner
Interaction with 3D Models on Virtual Archaeological Sites
Lidia M. Ortega, Ángel-Luis García-Fernández, José-Luis López, and Alberto Calzado
Traditional-based Visualization Methods for Archaeological 3D Data: an Evaluation
Paulo Bernardes, Joaquim Madeira, and Manuela Martins
Geometry and Modelling
SynthPS: a Benchmark for Evaluation of Photometric Stereo Algorithms for Cultural Heritage Applications
Tinsae Gebrechristos Dulecha, Ruggero Pintus, Enrico Gobbetti, and Andrea Giachetti
Easy Authoring of Image-Supported Short Stories for 3D Scanned Cultural Heritage
Marc Comino, Antoni Chica, and Carlos Andujar
Anatomy Changes and Virtual Restoration of Statues
Tong Fu, Raphaelle Chaine, and Julie Digne
Another Brick in the Wall: Improving the Assisted Semantic Segmentation of Masonry Walls
Gaia Pavoni, Francesca Giuliani, Anna De Falco, Massimiliano Corsini, Federico Ponchio, Marco Callieri, and Paolo Cignoni
Virtual/Augmented Reality and Image Processing
Engaging audiences with Cultural Heritage through Augmented Reality (AR) Enhanced Pop-Up Books
Yaqin Huang, Karina Rodriguez Echavarria, and Simon Julier
Sunlight Simulation of the Church of Saint Nectaire in Virtual Reality: a Digital Time Machine
Renato Saleri
Segmentation-Based Near-Lossless Compression of Multi-View Cultural Heritage Image Data
Max von Buelow, Reimar Tausch, Volker Knauthe, Tristan Wirth, Stefan Guthe, Pedro Santos, and Dieter W. Fellner
Posters
Digital Layered Models of Architecture and Mural Paintings over Time
Milagros Guardia, Paola Pogliani, Giulia Bordi, Panayiotis Charalambous, Carlos Andujar, and Xavier Pueyo
Possibilities and Challenges of Portraying Cultural Heritage Artefacts using Augmented Reality: the Mjällby Crucifix Case Study
Valeria Garro, Veronica Sundstedt, Advaith Putta, and Christoffer Sandahl
A NLP Enhanced Visual Analytics Tool for Archives Metadata
Anil Ozdemir, Dilara Müstecep, Orhan Agaoglu, and Selim Balcisoy
Virtual/Augmented Reality and Museum Applications
Augmented Reality for Sculpture Stability Analysis and Conservation
Dennis Henneman, Yichen Li, John Ochsendorf, Margrit Betke, and Emily Whiting
The V-Horus Project
Andrea Lennhoff, Luiz Velho, Bernado Alevato, Luiza Novaes, and Jorge Lopes
Ernst Grube: A Contemporary Witness and His Memories Preserved with Volumetric Video
Markus Worchel, Marcus Zepp, Weiwen Hu, Oliver Schreer, Ingo Feldmann, and Peter Eisert
Archaeo Puzzle: An Educational Game Using Natural User Interface for Historical Artifacts
Nicola Capece, Ugo Erra, Monica Gruosso, and Marco Anastasio

BibTeX (GCH 2020 - Eurographics Workshop on Graphics and Cultural Heritage)
@inproceedings{
10.2312:gch.20201286,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Interaction with 3D Models on Virtual Archaeological Sites}},
author = {
Ortega, Lidia M.
and
García-Fernández, Ángel-Luis
and
López, José-Luis
and
Calzado, Alberto
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201286}
}
@inproceedings{
10.2312:gch.20201285,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Semi-automated Annotation of Repetitive Ornaments on 3D Painted Pottery Surfaces}},
author = {
Lengauer, Stefan
and
Komar, Alexander
and
Karl, Stephan
and
Trinkl, Elisabeth
and
Sipiran, Ivan
and
Schreck, Tobias
and
Preiner, Reinhold
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201285}
}
@inproceedings{
10.2312:gch.20201287,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Traditional-based Visualization Methods for Archaeological 3D Data: an Evaluation}},
author = {
Bernardes, Paulo
and
Madeira, Joaquim
and
Martins, Manuela
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201287}
}
@inproceedings{
10.2312:gch.20201289,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Easy Authoring of Image-Supported Short Stories for 3D Scanned Cultural Heritage}},
author = {
Comino Trinidad, Marc
and
Chica, Antoni
and
Andujar, Carlos
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201289}
}
@inproceedings{
10.2312:gch.20201288,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
SynthPS: a Benchmark for Evaluation of Photometric Stereo Algorithms for Cultural Heritage Applications}},
author = {
Dulecha, Tinsae Gebrechristos
and
Pintus, Ruggero
and
Gobbetti, Enrico
and
Giachetti, Andrea
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201288}
}
@inproceedings{
10.2312:gch.20201290,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Anatomy Changes and Virtual Restoration of Statues}},
author = {
Fu, Tong
and
Chaine, Raphaelle
and
Digne, Julie
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201290}
}
@inproceedings{
10.2312:gch.20201291,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Another Brick in the Wall: Improving the Assisted Semantic Segmentation of Masonry Walls}},
author = {
Pavoni, Gaia
and
Giuliani, Francesca
and
Falco, Anna De
and
Corsini, Massimiliano
and
Ponchio, Federico
and
Callieri, Marco
and
Cignoni, Paolo
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201291}
}
@inproceedings{
10.2312:gch.20201292,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Engaging audiences with Cultural Heritage through Augmented Reality (AR) Enhanced Pop-Up Books}},
author = {
Huang, Yaqin
and
Rodriguez Echavarria, Karina
and
Julier, Simon
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201292}
}
@inproceedings{
10.2312:gch.20201293,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Sunlight Simulation of the Church of Saint Nectaire in Virtual Reality: a Digital Time Machine}},
author = {
Saleri, Renato
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201293}
}
@inproceedings{
10.2312:gch.20201294,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Segmentation-Based Near-Lossless Compression of Multi-View Cultural Heritage Image Data}},
author = {
Buelow, Max von
and
Tausch, Reimar
and
Knauthe, Volker
and
Wirth, Tristan
and
Guthe, Stefan
and
Santos, Pedro
and
Fellner, Dieter W.
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201294}
}
@inproceedings{
10.2312:gch.20201296,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Possibilities and Challenges of Portraying Cultural Heritage Artefacts using Augmented Reality: the Mjällby Crucifix Case Study}},
author = {
Garro, Valeria
and
Sundstedt, Veronica
and
Putta, Advaith
and
Sandahl, Christoffer
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201296}
}
@inproceedings{
10.2312:gch.20201295,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Digital Layered Models of Architecture and Mural Paintings over Time}},
author = {
Guardia, Milagros
and
Pogliani, Paola
and
Bordi, Giulia
and
Charalambous, Panayiotis
and
Andujar, Carlos
and
Pueyo, Xavier
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201295}
}
@inproceedings{
10.2312:gch.20201297,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
A NLP Enhanced Visual Analytics Tool for Archives Metadata}},
author = {
Ozdemir, Anil
and
Müstecep, Dilara
and
Agaoglu, Orhan
and
Balcisoy, Selim
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201297}
}
@inproceedings{
10.2312:gch.20201299,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
The V-Horus Project}},
author = {
Lennhoff, Andrea
and
Velho, Luiz
and
Alevato, Bernado
and
Novaes, Luiza
and
Lopes, Jorge
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201299}
}
@inproceedings{
10.2312:gch.20201298,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Augmented Reality for Sculpture Stability Analysis and Conservation}},
author = {
Henneman, Dennis
and
Li, Yichen
and
Ochsendorf, John
and
Betke, Margrit
and
Whiting, Emily
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201298}
}
@inproceedings{
10.2312:gch.20201300,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Ernst Grube: A Contemporary Witness and His Memories Preserved with Volumetric Video}},
author = {
Worchel, Markus
and
Zepp, Marcus
and
Hu, Weiwen
and
Schreer, Oliver
and
Feldmann, Ingo
and
Eisert, Peter
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201300}
}
@inproceedings{
10.2312:gch.20201301,
booktitle = {
Eurographics Workshop on Graphics and Cultural Heritage},
editor = {
Spagnuolo, Michela and Melero, Francisco Javier
}, title = {{
Archaeo Puzzle: An Educational Game Using Natural User Interface for Historical Artifacts}},
author = {
Capece, Nicola
and
Erra, Ugo
and
Gruosso, Monica
and
Anastasio, Marco
}, year = {
2020},
publisher = {
The Eurographics Association},
ISSN = {2312-6124},
ISBN = {978-3-03868-110-6},
DOI = {
10.2312/gch.20201301}
}

Browse

Recent Submissions

Now showing 1 - 18 of 18
  • Item
    GCH 2020: Frontmatter
    (The Eurographics Association, 2020) Spagnuolo, Michela; Melero, Francisco Javier; Spagnuolo, Michela and Melero, Francisco Javier
  • Item
    Interaction with 3D Models on Virtual Archaeological Sites
    (The Eurographics Association, 2020) Ortega, Lidia M.; García-Fernández, Ángel-Luis; López, José-Luis; Calzado, Alberto; Spagnuolo, Michela and Melero, Francisco Javier
    The extraction of artifacts during the excavation of an archaeological site usually implies the loss of spatial references among the extracted vestiges. In this work we introduce a way to compute spatial relationships among the finds in an excavation, as well as a method for accessing the information on the database through the virtual 3D representation of an archaeological site. The spatial relationships are encoded in the database using the Dimensionally Extended Nine-Intersection Model (DE-9IM).
  • Item
    Semi-automated Annotation of Repetitive Ornaments on 3D Painted Pottery Surfaces
    (The Eurographics Association, 2020) Lengauer, Stefan; Komar, Alexander; Karl, Stephan; Trinkl, Elisabeth; Sipiran, Ivan; Schreck, Tobias; Preiner, Reinhold; Spagnuolo, Michela and Melero, Francisco Javier
    The creation of drawings from the surface of painted pottery artifacts is an important practice in archaeological research and documentation. Traditional approaches include manual drawings using pen and paper, either directly on the physical surface, or from photographs, while more recent approaches are supported by photography or flattening of 3D digitized objects. Elaborate vase paintings, mostly showing figural scenes, often comprise ornamental decorations in secondary position or in the background, exhibiting repetitive patterns. We propose a tool supporting the creation of archaeological drawings with a semi-automatic extraction of ornamental surface sections, based on a combination of user-defined queries and self-similarity detection. Appropriate heuristics allow to detect the presence and positions of ornamental bands, a frequently occurring scheme, where ornamental primitives are evenly spaced along the tangential direction of a vessel's solid of revolution. Our interactive tool allows domain experts to efficiently select ornamental queries, and assess the quality of resulting similarity detections. First experiments with real world artifacts from ancient Greek and Peruvian cultures confirm the feasibility of the approach.
  • Item
    Traditional-based Visualization Methods for Archaeological 3D Data: an Evaluation
    (The Eurographics Association, 2020) Bernardes, Paulo; Madeira, Joaquim; Martins, Manuela; Spagnuolo, Michela and Melero, Francisco Javier
    3D archaeological visualization is an increasingly frequent and necessary practice, but it still faces application issues. Those are substantiated by the use of visualization tools that are not customized for the archaeological needs and the privileged use of the visual features of models during the archaeological process stages. We propose some visualization methods, based on procedures traditionally practised in archaeology, to stimulate and facilitate their use for 3D visualization of archaeological data. The proposed methods were evaluated by archaeologists to assess their usability and usefulness in the archaeological process. The evaluation concluded that the proposed visualization methods increase the perception of the archaeological 3D models. It was also possible to reveal new elements of archaeological interest.
  • Item
    Easy Authoring of Image-Supported Short Stories for 3D Scanned Cultural Heritage
    (The Eurographics Association, 2020) Comino Trinidad, Marc; Chica, Antoni; Andujar, Carlos; Spagnuolo, Michela and Melero, Francisco Javier
    Visual storytelling is a powerful tool for Cultural Heritage communication. However, traditional authoring tools either produce videos that cannot be fully integrated with 3D scanned models, or require 3D content creation skills that imply a high entry barrier for Cultural Heritage experts. In this paper we present an image-supported, video-based authoring tool allowing non- 3D-experts to create rich narrative content that can be fully integrated in immersive virtual reality experiences. Given an existing 3D scanned model, each story is based on a user-provided photo or system-proposed image. First, the system automatically registers the image against the 3D model, and creates an undistorted version that will serve as a fixed background image for the story. Authors can then use their favorite presentation software to annotate or edit the image while recording their voice. The resulting video is processed automatically to detect per-frame regions-of-interest. At visualization time, videos are projected onto the 3D scanned model, allowing the audience to watch the narrative piece in its surrounding spatial context. We discuss multiple color blending techniques, inspired by detail textures, to provide high-resolution detail. The system uses the image-to-model registration data to find suitable locations for triggers and avatars that draw the user attention towards the 3D model parts being referred to by the presenter. We conducted an informal user study to evaluate the quality of the immersive experience. Our findings suggest that our approach is a valuable tool for fast and easy creation of fully-immersive visual storytelling experiences.
  • Item
    SynthPS: a Benchmark for Evaluation of Photometric Stereo Algorithms for Cultural Heritage Applications
    (The Eurographics Association, 2020) Dulecha, Tinsae Gebrechristos; Pintus, Ruggero; Gobbetti, Enrico; Giachetti, Andrea; Spagnuolo, Michela and Melero, Francisco Javier
    Photometric Stereo (PS) is a technique for estimating surface normals from a collection of images captured from a fixed viewpoint and with variable lighting. Over the years, several methods have been proposed for the task, trying to cope with different materials, lights, and camera calibration issues. An accurate evaluation and selection of the best PS methods for different materials and acquisition setups is a fundamental step for the accurate quantitative reconstruction of objects' shapes. In particular, it would boost quantitative reconstruction in the Cultural Heritage domain, where a large amount of Multi-Light Image Collections are captured with light domes or handheld Reflectance Transformation Imaging protocols. However, the lack of benchmarks specifically designed for this goal makes it difficult to compare the available methods and choose the most suitable technique for practical applications. An ideal benchmark should enable the evaluation of the quality of the reconstructed normals on the kind of surfaces typically captured in real-world applications, possibly evaluating performance variability as a function of material properties, light distribution, and image quality. The evaluation should not depend on light and camera calibration issues. In this paper, we propose a benchmark of this kind, SynthPS, which includes synthetic, physically-based renderings of Cultural Heritage object models with different assigned materials. SynthPS allowed us to evaluate the performance of classical, robust and learning-based Photometric Stereo approaches on different materials with different light distributions, also analyzing their robustness against errors typically arising in practical acquisition settings, including robustness against gamma correction and light calibration errors.
  • Item
    Anatomy Changes and Virtual Restoration of Statues
    (The Eurographics Association, 2020) Fu, Tong; Chaine, Raphaelle; Digne, Julie; Spagnuolo, Michela and Melero, Francisco Javier
    Restoration of archaeological artefacts is an important task for cultural heritage preservation. However traditional restoration processes are difficult, costly and sometimes risky for the artefact itself, due to poor restoration choices for example. To avoid this, it is interesting to turn to virtual restoration, which allows to test restoration hypotheses, that can be later carried out on the real artefact. In this paper, we introduce a restoration framework for completing missing parts of archaeological statues, with a focus on human sculptures. Our approach proceeds by registering an anatomical model to a statue, identifying the missing parts. Compatible statues are then provided by the users and their poses are changed to match the broken statue, using a point-cloud specific skinning technique. The modified statues provide replacement parts which are blended in the original statue.
  • Item
    Another Brick in the Wall: Improving the Assisted Semantic Segmentation of Masonry Walls
    (The Eurographics Association, 2020) Pavoni, Gaia; Giuliani, Francesca; Falco, Anna De; Corsini, Massimiliano; Ponchio, Federico; Callieri, Marco; Cignoni, Paolo; Spagnuolo, Michela and Melero, Francisco Javier
    In Architectural Heritage, the masonry's interpretation is an essential instrument for analyzing the construction phases, the assessment of structural properties, and the monitoring of its state of conservation. This work is generally carried out by specialists that, based on visual observation and their knowledge, manually annotate ortho-images of the masonry generated by photogrammetric surveys. This results in vectorial thematic maps segmented according to their construction technique (isolating areas of homogeneous materials/structure/texture) or state of conservation, including degradation areas and damaged parts. This time-consuming manual work, often done with tools that have not been designed for this purpose, represents a bottleneck in the documentation and management workflow and is a severely limiting factor in monitoring large-scale monuments (e.g.city walls). This paper explores the potential of AI-based solutions to improve the efficiency of masonry annotation in Architectural Heritage. This experimentation aims at providing interactive tools that support and empower the current workflow, benefiting from specialists' expertise.
  • Item
    Engaging audiences with Cultural Heritage through Augmented Reality (AR) Enhanced Pop-Up Books
    (The Eurographics Association, 2020) Huang, Yaqin; Rodriguez Echavarria, Karina; Julier, Simon; Spagnuolo, Michela and Melero, Francisco Javier
    One of the core activities of memory institutions is to provide access to heritage material from their collections so that it can be used in formal and informal educational activities. Although this type of access is beneficial for audiences, we argue that current digital technologies for access still require users to know in which collection they must look for a specific subject or type of content. Although collection aggregators, such as Europeana and Google Arts and Culture, have made it easier to access content across collections, there is still a lack of engaging interfaces which can draw the interest amongst a wide range of audiences for exploring heritage material. In this research, we propose a tangible interface for accessing Cultural Heritage (CH) content in the form of a pop-up book. Pop-up books are a highly engaging way to get audiences to interact with materials in archives and collections. Our approach is creative and playful as it takes advantage of both the narrative and the three-dimensional and tactile nature of pop-up books so that audiences can engage with digital content through Augmentation Reality (AR). The technical contributions of the paper include a method to enable real-time interaction between the physical elements of the book and the virtual content. Unlike other AR pop-up books that generate purely virtual pop-up content, our design preserves the original 3D model inside the books and generates virtual effects on those objects, making our application more appealing and engaging than other AR books. This approach and technical method are deployed using a commercially available pop-up book with stories about various famous landmarks in the city of London. Content drawn from heritage collections enriches the stories told in the book with additional visual content and interactions. Initial tests of this approach suggest that it has the potential to engage audiences who will not be traditionally inclined to access other platforms with CH content.
  • Item
    Sunlight Simulation of the Church of Saint Nectaire in Virtual Reality: a Digital Time Machine
    (The Eurographics Association, 2020) Saleri, Renato; Spagnuolo, Michela and Melero, Francisco Javier
    The roman church of Saint Nectaire, like many churches in Auvergne, France, is richly decorated with carved capitals. Most of them represent figures or symbols of Christianity and are periodically illuminated by the sunlight that comes to strike them at different times of the day throughout the year. The periodicity of these occurrences, which seem to correspond to a "targeted" temporality around religious feasts, appeals to historians who foresee the possibility of a perpetual religious calendar marking the times of the Christian liturgy with regularity and precision. The observations made since 2009 by Daniel Tardy [Dan13] have made it possible to highlight the high number of luminous phenomena, particularly concerning the remarkable lighting of the choir capitals: this has made it possible to hypothesize peculiar coincidences between the day of the luminous event and the date of the Julian calendar (used from 46 B.C. to 1582 AD) corresponding to the Christian celebration of the illuminated figures. The presence of hills, however, recurrently masks the sun at the beginning and end of the day and prevents the illumination on a certain number of sculpted figures that one would expect, given the number of calendar occurrences already observed elsewhere. Considering its experience in the field of digital survey 3D modeling and real-time simulation in the field of heritage [ASL15], [MDSB14], [NMRS13], [SCN*13], [Sal18], the MAP laboratory created a complete numerical model of the church and to submit it to a virtual heliodon in order to predict the illumination of the interior decorative elements at "critical" moments throughout the year if the surrounding hills did not exist: the question of the primary location of the church is currently the subject of many conjectures. This experiment consists in a methodological approach whose purpose is to validate a solar simulation method on an existing building and to verify its validity by direct confrontation between the simulation produced and the observable effects in reality. This not only allows us to make hypotheses about the constructive history of the the church of Saint Nectaire, but also - in the near future- to apply this method to several nearby churches, similar in their history, their architecture and their religious iconography.
  • Item
    Segmentation-Based Near-Lossless Compression of Multi-View Cultural Heritage Image Data
    (The Eurographics Association, 2020) Buelow, Max von; Tausch, Reimar; Knauthe, Volker; Wirth, Tristan; Guthe, Stefan; Santos, Pedro; Fellner, Dieter W.; Spagnuolo, Michela and Melero, Francisco Javier
    Cultural heritage preservation using photometric approaches received increasing significance in the past years. Capturing of these datasets is usually done with high-end cameras at maximum image resolution enabling high quality reconstruction results while leading to immense storage consumptions. In order to maintain archives of these datasets, compression is mandatory for storing them at reasonable cost. In this paper, we make use of the mostly static background of the capturing environment that does not directly contribute information to 3d reconstruction algorithms and therefore may be approximated using lossy techniques. We use a superpixel and figure-ground segmentation based near-lossless image compression algorithm that transparently decides if regions are relevant for later photometric reconstructions. This makes sure that the actual artifact or structured background parts are compressed with lossless techniques. Our algorithm achieves compression rates compared to the PNG image compression standard ranging from 1:2 to 1:4 depending on the artifact size.
  • Item
    Possibilities and Challenges of Portraying Cultural Heritage Artefacts using Augmented Reality: the Mjällby Crucifix Case Study
    (The Eurographics Association, 2020) Garro, Valeria; Sundstedt, Veronica; Putta, Advaith; Sandahl, Christoffer; Spagnuolo, Michela and Melero, Francisco Javier
    The increasing application of immersive technologies, i.e. virtual reality (VR) and augmented reality (AR), in cultural heritage (CH) offers new ways of displaying artefacts and historical sites. VR and AR provide an added value to the visitor experience from several different aspects, e.g. interactivity or sense of presence. VR and AR technologies open the possibility for the visitor to visit reconstructions of historical sites and observe 3D replicas of CH artefacts. Moreover, these technologies, especially AR, can bring some artefacts back to their historical locations adding a new dimension to the visitor experience. We present an ongoing case study exploring the use of AR in the portrayal of a CH artefact, namely the Mjällby Crucifix in the Blekinge Museum, located in Southern Sweden. This crucifix is a medieval artefact which was originally placed in the Mjällby church and is currently preserved at the Blekinge Museum warehouse. The artefact is displayed lying in horizontal position on a low stage surrounded by other artefacts. Due to its large size (310 cm high and 260 cm wide) and its current position, it is not possible for the visitor to have a close view of the artefact. We plan to display a 3D replica of the artefact via an AR application using a hand-held device. The digital replica can be visualised in its original vertical position both in a chosen location in the museum and in the Mjällby church enhancing the visitor experience. A prototype of the AR application has been developed and showcased to a group of experts from the Blekinge Museum. The digitisation of the crucifix artefact has been done using an Artec Leo 3D scanner which captures both geometry and texture information. We developed a marker-based AR prototype application which runs on Android mobile devices supporting Google AR platform ARCore. We used a picture of the original crucifix as a marker image. The application detects this image which is supposed to lie on the floor or another horizontal surface, and displays the 3D model of the crucifix on top of it. An online questionnaire followed by a group interview with experts in the CH domain was conducted to discuss the AR prototype and the possibilities and challenges with the use of AR technology in digital CH. We focused on the context of Blekinge Museum exhibitions as an example of a regional museum. Four experts filled in the questionnaire and three of them participated in the group interview consisting of two stages. In the first part the experts were shown the AR prototype. This was followed by a group discussion mainly driven from the participants. In the second part the moderator presented additional considerations prepared in advance by the organisers by collecting personal reflections and information from background literature in the area of computer graphics applied to CH. The aim was to include a different perspective in the discussion and to gather insights about the potential differences and knowledge gaps between experts of different domains. Answers from the questionnaire and the group discussion highlighted established capability of AR technology such as exhibition enhancement and interaction, appealing to new target audiences and the possibility to display artefacts outside the museum: (i) expanding the geographic area of impact of the museum that aims at covering the regional territory, (ii) attracting visitors to the museum as sort of preview of the type of artefacts available on site. Regarding the challenges, much focus emerged on the cost of the technology, the necessity of building specific competence and expertise among the museum staff, and the usability and accessibility aspects of the AR applications. The Bring Your Own Device (BYOD) policy was mentioned as the ideal solution to tackle the problem of the costs of the devices which support also the usability since the visitors are more accustomed to handling their own devices. The BYOD policy implies the requirement of being available to the largest number of visitors, hence the AR application should be multiplatform and its availability should not be limited to the most recent and powerful mobile devices. Other mentioned challenges were the restricted computational resources of the devices and the necessity of applications maintenance (software updates). Aspects related to health and safety of sharing devices have also been discussed. The presented case study highlighted relevant aspects considered by the experts as well as providing new insights to take into account to make AR technology successful in virtual CH exhibitions of a regional museum. Future work will include improving the AR prototype adding interaction with the artefact, showcasing the AR prototype in the original location of the artefact to collect non-expert visitors expectations and run a usability study of the AR application. This work was supported in part by KK-stiftelsen Sweden, through the ViaTecH Synergy Project (contract 20170056).
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    Digital Layered Models of Architecture and Mural Paintings over Time
    (The Eurographics Association, 2020) Guardia, Milagros; Pogliani, Paola; Bordi, Giulia; Charalambous, Panayiotis; Andujar, Carlos; Pueyo, Xavier; Spagnuolo, Michela and Melero, Francisco Javier
    The European project Enhancement of Heritage Experiences: The Middle Ages. Digital Layered Models of Architecture and Mural Paintings over Time (EHEM), approved in the call for JPICH Conservation, Protection and Use (0127) in the year 2020, aims to obtain virtual reconstructions of medieval artistic heritage - architecture with mural paintings - that are as close as possible to the original at different times, incorporating historical-artistic knowledge and the diachronic perspective of heritage, as an instrument for researchers, restorers and heritage curators and to improve the visitor's perceptions and experiences. In the digital models elaborated we intend to develop, as concrete objectives: 1. The understanding of architectural complexity, which is usually regularized geometrically. 2. Solving chromatic problems. The analysis of pigments, the arrangement of the pictorial layers and the successive restorations suffered, with the help of conservation and restoration technicians, will allow us to digitally specify the original colouring of the paintings. 3. Raise and propose the resolution of lighting problems. To date, trials have been carried out for the restitution of these problems in digital models based on the analysis of natural lighting, which we intend to improve. We also propose to deal with artificial lighting by chandeliers or oil lamps, which produced effects of painting vibration at the moment when, for liturgical reasons, the images ''acted''. 4. To approach digitally the different perspectives of the medieval building and its paintings according to the categories of users. To this end we have chosen three sites that because of their complexity will serve as case studies: The early medieval church of Santa Maria Antiqua in Rome (Italy), a mural palimpsest, consisting of up to ten layers of overlapping painted plasters, realised during a relatively short period of life (sixth-ninth centuries), which also poses architectural challenges of visual resolution given that it was transformed into a church from the Domitianic entrance hall in the Roman Forum to the imperial Palace on the Palatine hill. The hermitage of Sant Quirze de Pedret (Spain), with its complex architectural genesis from the tenth century, was decorated at the head of the church at two different times by superimposing a layer on the previous one. The discovery of its paintings, their removal and the transfer to two museums took place at two different moments (1921 and 1937) and with very different procedures. At the same time, years later, radical interventions were made to the building, altering the two pictorial phases in its ''virtual'' presentation. The Engleistra or Place of Seclusion founded by Neophytos (Agios Neophytos Monastery, Cyprus) The oratory was excavated in the rock from a natural cave and was decorated, at different times during the Middle Ages, with Byzantine wall paintings. The extreme nature of the site and the irregular nature of the rocky surface that house these cycles, comprising of up to five phases constitute a fundamental challenge for their digital presentation.
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    A NLP Enhanced Visual Analytics Tool for Archives Metadata
    (The Eurographics Association, 2020) Ozdemir, Anil; Müstecep, Dilara; Agaoglu, Orhan; Balcisoy, Selim; Spagnuolo, Michela and Melero, Francisco Javier
    Today, almost all cultural heritage (CH) institutions are starting to digitize parts of their collections and archives to improve accessibility, preservation of originals, publicity, and visibility of the institution on the Internet. With this recent development, digital document collections have been multiplying. These collections are spread over more than one area of life in a vast domain, including art, history, mathematics, physics, etc. Such a situation creates a substantial volume of documents digitally available. Also, it creates the need for various approaches that allow users to understand latent meanings in collections, discover and investigate relationships, and extract the necessary information from collections. To address this need, we introduce a visual exploratory tool that facilitates the uncovering of hidden information and stories underlying documents, extracting the key individuals, temporal expressions, locations, entities, and keywords within the documents ,establishing a network between documents and allow researchers and archivists to form and test hypotheses and observe individual relationships, networks, and stories present in the archives metadata collections.Consequently, we have designed and developed a visual exploration tool for large archives with limited metadata employing state of the art Natural Language Processing (NLP) techniques to assist cultural heritage researchers. To design such a tool, we have collaborated with archive professionals from an cultural institution, SALT (https:// saltonline.org/) which focused on public service producing research-based exhibitions, publications, and digitization projects. As a result of our conversations Salt team we decided to use Waqfs of Crete which is an archive consisting of official records of Muslim inhabitants of Crete. Documents spanning the period from 1825 to 1928 in Ottoman Turkish and Greek provide an opportunity to examine the multi-layered social structure on the island, especially from a cultural and economic perspective. The metadata contains information for approximately 10 thousand documents and includes the summary of those documents, the year they were published, the location, the language used, and the documents' picture. Also, We extracted various features including locations, key individuals, dates, entities and keywords from the document summaries on metadata using NLP methods including regular expressions for extracting , and word embedding models for capturing similarities between documents. We have integrated all of these features into designed tool to let the user to see networks that can represent the relationship between documents, as well as easily access similar documents in the archive. In the network we demonstrated, particular nodes correspond to the documents itself. To assign an weighted edge between two documents in the network, the total number of shared individuals and keywords between documents are computed and edges are set based on a predetermined threshold value. This threshold has been found by manually tweaking both considering the speed at which the result is reflected on the application and average number of shared attributes. To capture similarity between documents, we used state-of-theart word embedding models including Word2vec, FastText and Transformer which provides a method to compute dense vector representations for documents. Consequently, each document was represented as fixed-sized mathematical vectors as output of each model, and the similarity between documents was calculated by taking the arithmetic cosine similarities of vectors. The designed interface consisting of six components which includes interactive map that allows the user to view documents in different locations and view the document networks that formed by calculating total number of shared attributes between documents. Remaining components include information box that contains document-specific attributes such as location, time, person, entities, and keyword, document browser that enable users and researchers to browse documents easily, individual and keyword search menu and filtering panel. In this way, the users may find documents that are roughly related to each other very quickly. Later, the user can browse each document on its network and view documents that have common individuals and keywords with each other. Thus, the user may follow the interactions between documents like a story and able to do this for all the people who lived in the 19th century on Crete's island.
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    The V-Horus Project
    (The Eurographics Association, 2020) Lennhoff, Andrea; Velho, Luiz; Alevato, Bernado; Novaes, Luiza; Lopes, Jorge; Spagnuolo, Michela and Melero, Francisco Javier
    The V-Horus Project aims to reconstruct archaeological artefacts using digital technologies and to visualize them in an immersive experience in Virtual Reality. The focus of the project has been the reconstruction and 3D visualization of artefacts from the Egyptian collection of the National Museum of Brazil, in Rio de Janeiro, many of them destroyed in the fire in 2018. In this article, the multidisciplinary development process of the virtual reconstruction of a mummy from the roman period (30 BC to 395 AD) and the partcipants'immersive experience are reported. The results show that this experiment, which explores techniques of virtual reality, digital reconstruction, gaming, and immersive narrative expands the possibilities of visualization and groupings of artefacts in a museum; manages to engage the public; and has great symbolic value in enabling the digital reconstruction of destroyed objects of the collection
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    Augmented Reality for Sculpture Stability Analysis and Conservation
    (The Eurographics Association, 2020) Henneman, Dennis; Li, Yichen; Ochsendorf, John; Betke, Margrit; Whiting, Emily; Spagnuolo, Michela and Melero, Francisco Javier
    Augmented reality (AR) technology has provided museum visitors with more immersive experiences, but it has yet to reach its full potential for the conservators and historians who craft the exhibits and protect their cultural heritage. In this paper, we propose ConservatAR, an ongoing project that assists sculpture conservation in AR with physical simulation and data visualization. ConservatAR employs two techniques: a static analysis to predict tipping vulnerabilities for homogeneous sculptures, as well as a dynamic analysis for tipping detection and impact visualization of cracked and non-homogeneous sculptures during a user-controlled collapse. Formative user studies with conservators from the Museum of Fine Arts, Boston evaluate the usability and efficacy of our techniques, providing valuable insight on how AR can be best applied to art conservation.
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    Ernst Grube: A Contemporary Witness and His Memories Preserved with Volumetric Video
    (The Eurographics Association, 2020) Worchel, Markus; Zepp, Marcus; Hu, Weiwen; Schreer, Oliver; Feldmann, Ingo; Eisert, Peter; Spagnuolo, Michela and Melero, Francisco Javier
    ''Ernst Grube - The Legacy'' is an immersive Virtual Reality documentary about the life of Ernst Grube, one of the last German Holocaust survivors. From interviews conducted inside a volumetric capture studio, dynamic full-body reconstructions of both, the contemporary witness and its interviewer, are recovered. The documentary places them in virtual recreations of historical sites and viewers experience the interviews with unconstrained motion. As a step towards the documentary's production, prior work presents reconstruction results for one interview. However, the quality is unsatisfying and does not meet the requirements of the historical context. In this paper, we take the next step and revise the used volumetric reconstruction pipeline. We show that our improvements to depth estimation and a new depth map fusion method lead to a more robust reconstruction process and that our revised pipeline produces high-quality volumetric assets. By integrating one of our assets into a virtual scene, we provide a first impression of the documentary's look and the convincing appearance of protagonists in the virtual environment.
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    Archaeo Puzzle: An Educational Game Using Natural User Interface for Historical Artifacts
    (The Eurographics Association, 2020) Capece, Nicola; Erra, Ugo; Gruosso, Monica; Anastasio, Marco; Spagnuolo, Michela and Melero, Francisco Javier
    Serious games are very used educational tools that are proposed as entertainment games but with educational elements within them. Their focus is to create a practical and enjoyable learning experience using the latest innovative technologies such as human-computer interaction and 3D visualization systems. We use these two technologies to develop a 3D puzzle game where the users have to reconstruct ancient historical artifacts by using their hands tracked through the Leap Motion controller. The game has incremental difficulty and will test users in increasingly demanding challenges by proposing experiential learning, trying to impress in their minds the information contained in the game through the feeling during the gameplay by implementing the "Learning by doing" concept. Finally, we designed a controlled experiment to evaluate the sentiment, user experience, usability, and effectiveness of our tool, which will be carried out in future developments.