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https://hdl.handle.net/11050/50

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    Photo repair and 3d structure from flatbed scanners
    (2009-02) Pintus, Ruggero; Malzbender, Thomas; Wang, Oliver; Bergman, Ruth; Nachlieli, Hila; Ruckenstein, Gitit
    We introduce a technique that allows 3D information to be captured from a conventional flatbed scanner. The technique requires no hardware modification and allows untrained users to easily capture 3D datasets. Once captured, these datasets can be used for interactive relighting and enhancement of surface detail on physical objects. We have also found that the method can be used to scan and repair damaged photographs. Since the only 3D structure on these photographs will typically be surface tears and creases, our method provides an accurate procedure for automatically detecting these flaws without any user intervention. Once detected, automatic techniques, such as infilling and texture synthesis, can be leveraged to seamlessly repair such damaged areas. We first present a method that is able to repair damaged photographs with minimal user interaction and then show how we can achieve similar results using a fully automatic process.
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    Simulating Populations in Massive Urban Environments
    (2008) Balet, Olivier; Duysens, Jerome; Comptdaer, Jerome; Gobbetti, Enrico; Scopigno, Roberto
    The United Nations recently reported that the global proportion of urban population reached 49% in 2005 and that 60% of the global population is expected to live in cities by 2030. Urbanised areas are extremely vulnerable to all sorts of threats. Indeed, the combination of heavy population concentrations, critical infrastructures and built environments make it possible for environmental, industrial or man-made incidents to rapidly escalate into major disorders. Recent events have forcefully demonstrated that authorities at all levels of government turn out to be inadequately prepared for the intricacies and dilemmas of disasters in large urban environments. Therefore, innovative tools are needed to assist them in the studies, planning and inter-organizational preparation efforts, enabling to understand vulnerabilities and security issues, define and assess crisis management procedures, and train personnel. The CRIMSON research project has been funded by the European Commission in the field of Security Research to address this challenging need by researching, implementing and validating an innovative framework combining the latest virtual reality and simulation technologies. For that purpose, several technological challenges have been tackled by an international team of researchers, industrials and users, and important advances have been made in the following fields.
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    DART: the distributed agent based retrieval toolkit
    (2007) Angioni, Manuela; Demontis, Roberto; Deriu, Massimo; De Vita, Emanuela; Lai, Cristian; Marcialis, Ivan; Pintus, Antonio; Piras, Andrea; Soro, Alessandro; Tuveri, Franco
    The technology of search engines is evolving from indexing and classification of web resources based on keywords to more sophisticated techniques which take into account the meaning and the context of textual information and usage. Replying to query, commercial search engines face the user requests with a large amount of results, mostly useless or only partially related to the request; the subsequent refinement, operated downloading and examining as much pages as possible and simply ignoring whatever stays behind the first few pages, is left up to the user. Furthermore, architectures based on centralized indexes, allow commercial search engines to control the advertisement of online information, in contrast to P2P architectures that focus the attention on user requirements involving the end user in search engine maintenance and operation. To address such wishes, new search engines should focus on three key aspects: semantics, geo-referencing, collaboration/distribution. Semantic analysis lets to increase the results relevance. The geo-referencing of catalogued resources allows contextualisation based on user position. Collaboration distributes storage, processing, and trust on a world-wide network of nodes running on users’ computers, getting rid of bottlenecks and central points of failures. In this paper, we describe the studies, the concepts and the solutions developed in the DART project to introduce these three key features in a novel search engine architecture.
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    Pseudo-holographic device elicits rapid depth cues despite random-dot surface masking
    (Pion, 2007) Brelstaff, Gavin; Agus, Marco; Gobbetti, Enrico; Zanetti, Gianluigi
    Experiments with random-dot masking demonstrate that, in the absence of cues mundanely available to 2-D displays (object occlusion, surface shading, perspective foreshortening, and texture gradients), Holografika's large-screen multi-projector video system (COHERENT-IST-FP6-510166) elicits useful stereoscopic and motion-parallax depth cues, and does so in under 2 s. We employed a simplified version of Julesz's (c. 1971) famous spiral ramp surface: a 3-layer cylindrical wedding-cake--via an openGL model that subjects viewed along its concentric axis. By adjusting its parameters, two sets of model-stimuli were rendered: one with a uniform large field of depth and one where the field was effectively flat. Each of eleven, pre-screened, subjects completed four experiments, each consisting of eight trials in a 2IFC design whereby they indicated in which interval they perceived the greatest field of depth. The experiments tested one-eye static, one-eye head-swaying, two-eye static, and two-eye head-swaying observation--in that order. Scores improved also in that order.
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    A large scale interactive holographic display
    (IEEE, 2006) Agocs, Tibor; Balogh, Tibor; Forgacs, Tamas; Bettio, Fabio; Gobbetti, Enrico; Zanetti, Gianluigi
    Our work focuses on the development of interactive multi-user holographic displays that allow freely moving naked eye participants to share a three dimensional scene with fully continuous, observer independent, parallax. Our approach is based on a scalable design that exploits a specially arranged array of projectors and a holographic screen. The feasibility of such an approach has already been demonstrated with a working hardware and software 7.4M pixel prototype driven at 10-15Hz by two DVI streams. In this short contribution, we illustrate our progress, presenting a 50M pixel display prototype driven by a dedicated cluster hosting multiple consumer level graphic cards.