VAST: International Symposium on Virtual Reality, Archaeology and Intelligent Cultural Heritage - Short and Project Papers

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Browsing VAST: International Symposium on Virtual Reality, Archaeology and Intelligent Cultural Heritage - Short and Project Papers by Subject "Applications"

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    Cloud-based 3D Reconstruction of Cultural Heritage Monuments using Open Access Image Repositories
    (The Eurographics Association, 2014) Hadjiprocopis, Andreas; Wenzel, Konrad; Rothermel, Mathias; Ioannides, Marinos; Fritsch, Dieter; Klein, Michael; Johnsons, Paul S.; Weinlinger, Guenther; Doulamis, Anastasios; Protopapadakis, Eftychios; Kyriakaki, Georgia; Makantasis, Kostas; Fellner, Dieter W.; Stork, Andre; Santos, Pedro; Reinhard Klein and Pedro Santos
    A large number of photographs of cultural heritage items and monuments is publicly available in various Open Access Image Repositories (OAIR) and social media sites. Metadata inserted by camera, user and host site may help to determine the photograph content, geo-location and date of capture, thus allowing us, with relative success, to localise photos in space and time. Additionally, developments in Photogrammetry and Computer Vision, such as Structure from Motion (SfM), provide a simple and cost-effective method of generating relatively accurate camera orientations and sparse and dense 3D point clouds from 2D images. Our main goal is to provide a software tool able to run on desktop or cluster computers or as a back end of a cloud-based service, enabling historians, architects, archaeologists and the general public to search, download and reconstruct 3D point clouds of historical monuments from hundreds of images from the web in a cost-effective manner. The end products can be further enriched with metadata and published. This paper describes a workflow for searching and retrieving photographs of historical monuments from OAIR, such as Flickr and Picasa, and using them to build dense point clouds using SfM and dense image matching techniques. Computational efficiency is improved by a technique which reduces image matching time by using an image connectivity prior derived from low-resolution versions of the original images. Benchmarks for two large datasets showing the respective efficiency gains are presented.
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    IBISA: Making Image-Based Identification of Ancient Coins Robust to Lighting Conditions
    (The Eurographics Association, 2014) Marchand, Sylvain; Reinhard Klein and Pedro Santos
    The IBISA (Image-Based Identification/Search for Archaeology) system manages databases of digital images of archaeological objects, e.g. ancient coins, and allows the user to perform searches by examples. IBISA was de- signed to help the user decide, from their images, if two objects (coins) are either the same, come from the same matrix (die), share resemblance in style, or are completely different. The system searches for similarities in the databases using a registration method that must be resilient to the viewing conditions. Based on the Fourier trans- form, it cancels rigid transforms among images. Sub-pixel accuracy can be achieved with a very simple technique. However lighting conditions remain an issue. Fortunately, it is possible to extend this registration method to a light-independent model, considering the elevation or normal maps instead of intensity. The model is also useful for interactive visualization and museography. Although this model registration is now resilient to all viewing conditions, it is not practical in real scenarios where the target is a single image, from which a model can hardly be derived. Finally, a hybrid approach is investigated, with a target image but a model of the reference. It is more realistic, resilient to light conditions, gives excellent results with translations, but shows limitations for rotations.
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    The Use of Traditional and Computer-based Visualization in Archaeology: a User Survey
    (The Eurographics Association, 2012) Bernardes, Paulo; Madeira, Joaquim; Martins, Manuela; Meireles, José; David Arnold and Jaime Kaminski and Franco Niccolucci and Andre Stork
    Visualization methods are commonly used during the successive stages of the archaeological process. However, it is difficult to determine which methods are more intensively used in each stage and, also, which stage of the archaeological process is more demanding regarding visualization needs. Within a broader questionnaire regarding the use of computer tools, archaeologists were inquired about their use of traditional and computer-based visualization methods during the different stages of the archaeological process. The main survey results concerning visualization methods are presented and briefly analyzed.