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Now showing 1 - 10 of 22
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    High Dynamic Range Video for Cultural Heritage Documentation and Experimental Archaeology
    (The Eurographics Association, 2010) Happa, Jassim; Artusi, Alessandro; Czanner, Silvester; Chalmers, Alan; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    Video recording and photography are frequently used to document Cultural Heritage (CH) objects and sites. High Dynamic Range (HDR) imaging is increasingly being used as it allows a wider range of light to be considered that most current technologies are unable to natively acquire and reproduce. HDR video content however has only recently become possible at desirable, high definition resolution and dynamic range. In this paper we explore the potential use of a 20 f-stop HDR video camera for CH documentation and experimental archaeology purposes. We discuss data acquisition of moving caustics, flames, distant light and in participating media. Comparisons of Low Dynamic Range (LDR) and HDR content are made to illustrate the additional data that this new technology is able to capture, and the benefits this is likely to bring to CH documentation and experimental archaeology.
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    Analyzing Fracture Patterns in TheranWall Paintings
    (The Eurographics Association, 2010) Shin, Hijung; Doumas, Christos; Funkhouser, Thomas; Rusinkiewicz, Szymon; Steiglitz, Kenneth; Vlachopoulos, Andreas; Weyrich, Tim; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    In this paper, we analyze the fracture patterns observed in wall paintings excavated from Akrotiri, a Bronze Age Aegean city destroyed by earthquakes preceding a volcanic eruption on Thera (modern Santorini) around 1630 BC. We use interactive programs to trace detailed fragment boundaries in images of manually reconstructed wall paintings. Then, we use geometric analysis algorithms to study the shapes and contacts of those fragment boundaries, producing statistical distributions of lengths, angles, areas, and adjacencies found in assembled paintings. The result is a statistical model that suggests a hierarchical fracture pattern, where fragments break into two pieces recursively along cracks nearly orthogonal to previous ones. This model could be useful for predicting fracture patterns of other wall paintings and/or for guiding future computer-assisted reconstruction algorithms.
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    Exploration of Large-scale Museum Artifacts through Non-instrumented, Location-based, Multi-user Interaction
    (The Eurographics Association, 2010) Zabulis, Xenophon; Grammenos, Dimitris; Sarmis, Thomas; Tzevanidis, Kostantinos; Argyros, Antonis A.; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    This paper presents a system that supports the exploration of digital representations of large-scale museum artifacts in through non-instrumented, location-based interaction. The system employs a state-of-the-art computer vision system, which localizes and tracks multiple visitors. The artifact is presented in a wall-sized projection screen and it is visually annotated with text and images according to the location as well as walkthrough trajectories of the tracked visitors. The system is evaluated in terms of computational performance, localization accuracy, tracking robustness and usability.
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    3D-ISF: An Impact Measurement Tool for Business and Strategic Planning in ICT and 3D Heritage Applications
    (The Eurographics Association, 2010) Kaminski, Jaime; Mcloughlin, Jim; Sodagar, Babak; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    Despite the multitude of impact measurement techniques available to heritage site managers there is a case for the bigger strategic picture to figure more strongly in impact measurement decision making for ICT and 3D applications in the heritage sector. Discussions with heritage mangers raised the need for a holistic practical social impact model, one which combines impact measurement with overall strategic decision making considerations, accommodating internal and external dimensions of impact, as well as mission (and vision) and stakeholder perspectives ; and one that embeds impact as a dynamic issue for management in heritage organisations. In other words, there is a case for a total systems approach to impact which delivers from conceptualization to detailed implementation; right through to integrated strategic decision making. One that also can easily accommodate, if appropriate, other more specific measurement methods. The 3D ISF approach is broadly divided into two complementary elements. The left side of the framework considers the strategic perspective of the organisation. The right side of the framework encapsulates the impact measurement. The two elements are complementary and combine to form a holistic vision of the interaction between the site strategy, 3D deployment and its relationship to impact.
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    Fluid Interaction in Audio-Guided Museum Visit: Authoring Tool and Visitor Device
    (The Eurographics Association, 2010) Kaghat, Fatima-Zahra; Cubaud, Pierre; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    This paper presents an integrated system for location aware museum audio guide supporting sound spatialization. This system consists of a multi-modal visitor device composed of a head position, an orientation tracker and an audio headset. It aims at providing the visitor with a feeling of immersion within sounds virtually emanating from the artifacts exposed in the museum. The system is associated with a graphical authoring tool specifically designed for audio augmented reality in the context of museums. The proposed authoring tool enables to build the 3D representation of the museum, to add sound sources at different positions and altitudes, to build the virtual soundscape, and to create visitor scenarios describing how the visitor interacts with the soundscape while navigating through the museum artifacts. Experiments were conducted at the ' Musée des Arts et Métiers' in Paris, with the objective of reviving the machineries exposed at that museum by bringing to them the sound dimension from which they were deprived. The obtained results are very promising.
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    "The Approval of the Franciscan Rule" - Virtual Experience among the Characters of Giotto's Work
    (The Eurographics Association, 2010) Pietroni, Eva; Antinucci, Francesco; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    Within the exhibition ''Giotto's colours'' opened to public from the 10th of April to the 5th of September 2010 in ssisi, the National Research Council realized an innovative project creating a virtual environment from the scene ''The Rule Confirmation'', painted by Giotto in the Upper Basilica of St. Francis of ssisi at the end of the XIII century. The scene has been represented in 3D, starting from an accurate study of Giotto's space, characters, proportions and the models have been ''mapped'' using the original artistss painting. On this base two virtual reality installations have been realized. In the first one it is possible to virtually enter into the Giotto's Fresco. The scene is brought to life: characters are animated and represented while performing the action painted by the artist. Visitors can interact within the virtual space and mix with the characters without the support of traditional interfaces (mouse, joystick, keyboards, devices) but just using body movements, in a simple and natural way. In this way the space illustrated by Giotto becomes a place of experience open to multisensorial narration and participation. On the contrary, the approach of the second installation is descriptive and interpretative, focused on the spatial and perspective investigation of Giotto's fresco, in comparison with the 3d reconstruction. The primary objective of this experiment is to involve the observer in the scene painted by Giotto and to enable the visitor to feel and understand the message that Giotto was communicating.
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    Removing Shadows for Color Projection Using Sun Position Estimation
    (The Eurographics Association, 2010) Dellepiane, Matteo; Benedetti, Luca; Scopigno, Roberto; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    The result of an outdoors 3D scanning acquisition campaign is usually an accurate 3D model of the site, but in most of the cases the quality of the color acquired by the scanner is not satisfying. Alternative solutions, like the projection of a photographic dataset acquired in a different stage, are still dependent on the quality of the initial images. The short time for the acquisition campaigns and the weather conditions often force the shooting of images taken under a strong direct sun illumination. This generates colored models of poor quality. In this paper we present a method to estimate the sun position starting from a geo-referenced 3D model and a set of images. The sun position can enhance both the image alignment and color projection phases. Moreover, the detection and removal of the shadows from the images produces a better and more coherent color in the final 3D model. Using this kind of approach, outdoor sites can be acquired producing a high quality color information together with an accurate geometric measurement.
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    Natural Lighting, Gilts and Polychromy of Notre-Dame de Paris Cathedral
    (The Eurographics Association, 2010) Callet, Patrick; Dumazet, Sylvain; Leclercq, Christophe; Politi, Carine; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    Lighting either natural or not in the european medieval architecture (roman period) is studied and simulated around a special and famous example. "Notre-Dame de Paris" cathedral and its polychromy are studied for many years and, today the remains of polychromy are very reduced. This prestigious monument is then a unique opportunity to study the complex relationships between light, paint and gilt. Monumental polychromy of the religious buidings is now well established and some attempts exist for retrieving a kind of optical effects well controlled in the medieval era. An interdisciplinary study which derived from the french project TerraNumerica allowed to value a historical hypothesis about the possible optical role of gilts. Thanks to the simulation of a global illumination in spectral rendering operating with the photon mapping algorithm, a new interpretation of polychromy effects is proposed, including the lightguide effect produced by the gilts. Many measurements on formulated polychrome samples and spectrophotometric captures concerning natural lighting at sunset were made to validate that new hypothesis. The obtained results guided the interdisciplinary team on a new focus on the polychromy restitution of the medieval buildings and monuments. It became quite evident that the medieval sculptor brought a very high and accurate mastership in lighting. Playing with the symbolic and colored light for illuminating the Galerie des Rois (the kings of Judah and not the kings of France) he offered to the christian people a very "special effect" for the last minutes of the day time. Physically based simulations presented here show a brand new hypothesis concerning the optical role of gilts.
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    Verification and Acceptance Tests for High Definition 3D Surface Scanners
    (The Eurographics Association, 2010) Bathow, Christiane; Breuckmann, Bernd; Scopigno, Roberto; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    High definition three-dimensional (3D) surface scanners, based on structured light or laser light section techniques, have found a wide range of applications, especially for technical and industrial applications (mostly for measuring and inspection tasks). Since about 10 years, systems adapted for the requirements of arts and Cultural Heritage (CH) support 3D digitization of art objects. Although the use of digital 3D models in CH is rapidly growing, many of the users are not yet completely familiar with terminology and all details of technical specifications. As most of the users are practitioners there is sometimes only little experience with terms as data quality, accuracy, resolution, measurement uncertainty, especially because these terms are used in very different ways, in manuals and brochures of scanner manufacturers as well as by authors of scientific papers. Moreover, the objective of many applications is digitization instead of measurement; therefore, many users are not even aware, that they nevertheless have to care about metrology issues such as verification and acceptance tests of the used equipment to get a reliable scanning result. In its first part, the paper will give an overview the fundamentals of data acquisition and data processing, presenting also advantages and benefits, limitations and drawbacks as well as correlations between different performance parameters of high definition 3D surface scanners. Our goal is also to rectify a number of typical misunderstandings and to clarify related terms and definitions. In its second part, the paper will concentrate on verification and acceptance tests of high definition 3D scanners, reviewing the German guidelines VDI/VDE 2634/2 and proposing some preliminary extensions required to cope better with the CH domain.
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    WreckSight: Revealing our Submerged Maritime Heritage
    (The Eurographics Association, 2010) Rowland, Chris; Anderson, John; Alessandro Artusi and Morwena Joly and Genevieve Lucet and Denis Pitzalis and Alejandro Ribes
    This paper describes WreckSight, an interactive application for viewing aesthetically considered, accurate, 3D visualisations of historic shipwrecks on the seabed. Maritime heritage sites around the world, especially historic shipwrecks, are typically difficult to access by the general public. In many cases they are beyond the reach of traditional maritime archaeological investigation due to depth and low visibility. Historically significant wrecks have been successfully raised to the surface for research and public exposition in recent years. The Mary Rose raised in 1982 from Portsmouth harbour (UK) and the wreck of the US Civil War submarine Hunley recovered in 2000 from Charleston Bay, are on public display along with many artefacts recovered from the wrecks. However, the majority of historic shipwrecks lie at the site of their sinking, on the seabed, hidden from the public view. Recent improvements in multibeam sonar technologies have resulted in new opportunities to gather very high definition, 3D point cloud data from submerged historic shipwreck sites, therefore offering the potential to create highly accurate 3D images for public exposition. Traditional maritime archaeological methods for displaying this data can be improved by addressing a number of known problems. These are: - Gaps between points allow data to show through from the other side of the wreck, potentially misrepresenting the structure of the wreck. - Point cloud data contains no inherent colour information. Traditional display methods apply arbitrary colour ramps to the data which often does not enhance the viewer's interpretation of the wreck. - Points are rendered at the same size regardless of their distance from the viewer The WreckSight application resolves these problems by utilising occlusion objects, locally oriented colour ramps (Locoramps) and digital cinematography. This 3D visualisation tool also has applications beyond heritage, e.g. in the marine salvage industry, recreational dive planning and environmental management.