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Now showing 1 - 10 of 25
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    Multi-scalar 3D digitization of Cultural Heritage using a low-cost integrated approach
    (The Eurographics Association, 2013) Manferdini, Anna Maria; Russo, Michele; -
    In the architectural survey field, one of the main aspects to consider during a 3D digitization is the multi-scalar geometrical complexity of the artifact to acquire, besides other fundamental factors connected with the different aims of communication. Since the widespread of range-sensors has provided extremely versatile instruments able to easily acquire huge amount of data that can be processed for different uses and users and changing communication aims, the possibility to survey and restore high-quality 3D multi-resolution models has become an urgent need. Despite these developments, these technologies are still very expensive, need expertise and present persistent bottlenecks both in the reverse modeling process and in time consuming. In order to overcome these critical aspects and taking advantage of recent improvements of automated image-based technologies based on the Structure from Motion approach, this contribution presents some first results of investigations on the reliability of these low-cost technologies for the 3D digitization of Cultural Heritage. One of the main aims of these investigations rely on developing a procedure that could ease the work of surveyors called to represent artifacts at an architectural scale using fast and low-cost technologies. 3D models derived using the selected low-cost image-based technologies were compared among each other and with a 3D laser scanner gold standard acquisition. These investigations led to qualitative and quantitative evaluations and to considerations on times and skills required by all tested technologies. Strengths and weaknesses are highlighted, suggesting the best solution with respect to the optimization of all considered aspects. Finally, integration of different technologies are presented, as it represents the best solution in multi-scalar contexts.
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    Improving the digitization of shape and color of 3D artworks in a cluttered environment
    (The Eurographics Association, 2013) Bettio, Fabio; Gobbetti, Enrico; Merella, Emilio; Pintus, Ruggero; -
    We propose an approach for improving the digitization of shape and color of 3D artworks in a cluttered environment using 3D laser scanning and flash photography. In order to separate clutter from acquired material, semi-automated methods are employed to generate masks for segment the 2D range maps and the color photographs, removing unwanted 3D and color data prior to 3D integration. Sharp shadows generated by flash acquisition are trivially handled by this masking process, and color deviations introduced by the flash light are corrected at color blending time by taking into account the object geometry. The approach has been applied to, and evaluated on, a large scale acquisition campaign of the Mont'e Prama complex, an extraordinary collection of stone fragments from the Nuragic era, depicting larger-than-life archers, warriors, boxers, as well as small models of prehistoric nuraghe (cone-shaped stone towers). The acquisition campaign has covered 36 statues mounted on metallic supports, acquired at 0.25mm resolution, resulting in over 6200 range scans (over 1.3G valid samples) and 3426 10Mpixel photographs.
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    Replicating perishable artefacts. A project for analysis and exhibition of Early Medieval objects from the Byzantine village at Scorpo (Supersano, Italy)
    (The Eurographics Association, 2013) Bandiera, Adriana; Arthur, Paul; Imperiale, Marco Leo; Maffezzoli, Alfonso; Frigione, Mariaenrica; Montagna, Francesco; Signore, Grazia Maria; -
    Artefacts found in an archaeological excavation are sometimes made of perishable or fragile material like wood, iron, or leather. These present obvious conservation problems. This is the case of various artefacts from the Byzantine village of Scorpo (Supersano, southern Italy) that has been the object of excavations by archaeologists from the University of Salento (Italy) since 1999. In 2007 a number of wooden objects were discovered in a well, while in 2012 a hoard of ferrous objects was found near a drystone wall that perhaps enclosed the settlement. Given the highly fragile and perishable nature of the objects, the questions arise as to how to study these artefacts, preserve them for the future and display them to the public. In this paper we will illustrate the methodology developed at the University of Salento to give an answer to all these questions and we will describe the entire process ranging from the discovery of the artefacts, to their 3D digital acquisition and modeling, the eventual digital restoration, the realization of one or more physical copies using a rapid prototyping apparatus (RP), to their display in a museum. Digital models of artefacts and ancient contexts are increasingly used in museums in order to improve communication, also for the disabled. Furthermore, the resin replica of an object, created from its digital 3D model, can also be useful for its preservation and fruition, especially if it is fragile or in poor condition.
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    Surface Light Field from Video Acquired in Uncontrolled Settings
    (The Eurographics Association, 2013) Palma, Gianpaolo; Desogus, Nicola; Cignoni, Paolo; Scopigno, Roberto; -
    This paper presents an algorithm for the estimation of the Surface Light Field using video sequences acquired moving the camera around the object. Unlike other state of the art methods, it does not require a uniform sampling density of the view directions, but it is able to build an approximation of the Surface Light Field starting from a biased video acquisition: dense along the camera path and completely missing in the other directions. The main idea is to separate the estimation of two components: the diffuse color, computed using statistical operations that allow the estimation of a rough approximation of the direction of the main light sources in the acquisition environment; the other residual Surface Light Field effects, modeled as linear combination of spherical functions. From qualitative and numerical evaluations, the final rendering results show a high fidelity and similarity with the input video frames, without ringing and banding effects.
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    Feature-based automatic 3D registration for cultural heritage applications
    (The Eurographics Association, 2013) Tombari, Federico; Remondino, Fabio; -
    This paper presents a review of the state-of-the-art techniques in the field of 3D invariant features for the automatic registration of point clouds and 3D meshes. The paper proposes also a multi-stage 3D registration pipeline implemented using the PCL libraries. Experiments are carried out on datasets related to heritage scenarios and addressing large-scale outdoor data acquisitions as well as small objects.
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    A Low-Cost Portable 3D Laser Scanning System with Aptness from Acquisition to Visualization
    (The Eurographics Association, 2013) Banerjee, Sumandeep; Biswas, Prabir Kumar; Bhowmick, Partha; Dutta, Somnath; -
    This paper presents the design perspectives of a low-cost portable 3D laser scanning mechanism. The hardware is simple in design, easy to fabricate, and costs much less compared to the cheapest ones available in the market. Moreover, it is noninvasive and able to generate high-quality data sets. We present the complete design pipeline and discuss how to implement and put together the most recent algorithms. We propose this design for its wide applications to virtual reality simulation, 3D modeling, digitization of archaeological artifacts, automated defect inspection, object recognition etc.
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    3D documentation of Cultural Heritage artefacts: from data acquisition to virtual conservation and restoration
    (The Eurographics Association, 2013) Athanasiou, Eleni; Faka, Marina; Hermon, Sorin; Vassallo, Valentina; Yakoupi, Kyriaki; -
    This paper focuses on the development of a procedure for 3D documentation of Cultural Heritage assets and describes all the steps from the 3D data acquisition of the real object, the post processing the raw data and finally the digital recording, documentation and virtual preservation of the 3D data. It will also describe the experiences, carried out during the digital process, of some virtual restoration cases.
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    Design and implement a reality-based 3D digitisation and modelling project
    (The Eurographics Association, 2013) Remondino, Fabio; Menna, Fabio; Koutsoudis, Anestis; Chamzas, Christos; El-Hakim, Sabry; -
    3D digitisation denotes the process of describing parts of our physical world through finite measurements and representations that can be processed and visualised with a compute r system. Reality-based 3D digiti sation is essential for the documentation, conservation and preservation of our Cultural Heritage. This article composes a critical review of the digitisation pipeline, ranging from sensor selection and planning to data acquisition, processing and visualisation.
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    Reverse Engineering of Scale Models Using Dataflow Programming: Application to the fortification of plans-reliefs
    (The Eurographics Association, 2013) Jacquot, Kevin; Chevrier, Christine; Gilles, Halin; -
    Despite the progress in three-dimensional scanning, some architectural artifacts remain a digitizing challenge. Scale models and more especially the plans-reliefs of Louis XIV of France have specific characteristics such as size, scale, number, etc. A knowledge-based modeling approach is developed to address the limitations of digitizing tools. Our study deals with the fortified areas of the scale models. Bastioned fortification works extend over wide areas but they are built according to design rules. Once studied and organized, fortification knowledge has been used to create a library of parametric components. Implemented in Grasshopper, the components were manually adjusted to different practical cases. The library was then validated and we are now focusing on the automation of the adjustments of the components. Thereupon a reverse-engineering approach has been set up. Semantic segmentation algorithms have been defined and implemented in Grasshopper to automatically extract fortification features from 3D surveys based on the knowledge of fortification design rules. Along with the three-dimensional modeling of fortification, an automatic reconstruction of the city parts of the scale models is underway. Both these studies are part of a project aimed at valorizing and diffusing a very unique cultural heritage collection. As such, knowledge models are precious assets both the digitizing and the semantic enhancements of the final application.
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    Quick textured mesh generation for massive 3D digitization of museum artifacts
    (The Eurographics Association, 2013) Gonizzi, Sara; Micoli, Laura L.; Guidi, Gabriele; -
    The goal of the "3D Icons" European Project, is to provide Europeana with accurate 3D models of Cultural Heritage artifacts. The purpose of this paper is to describe the specific optimized processing pipeline that has been set-up for digitizing a significant part of the Civic Archaeological Museum in Milan (Italy). Many technical and logistic issues for capturing 3D models in a Museum environment are addressed. In such framework the main problem is generating a good result by the technical point of view, minimizing the impact on the usual Museum activity during 3D capture operations, while shortening the processing time to the minimal allowed by the different applicable techniques. This condition led to precise choices related to the 3D acquisition techniques to be used (SfM), and the related data processing. This paper illustrates the aforementioned systematic aspects through three practical examples, showing good practices for image capturing and some 3D processing optimizations that allowed to speed the 3D models production at a level compliant to the final goal of more than 500 models in 36 months.