CRS4 Libro, Contributo in un libro

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https://hdl.handle.net/11050/56

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Mostra il contenuto di CRS4 Libro, Contributo in un libro per Autore "Bettio, Fabio"

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    3D functional models of monkey brain through elastic registration of histological sections
    (Springer, 2005-09) Bettio, Fabio; Frexia, Francesca; Giachetti, Andrea; Gobbetti, Enrico; Pintore, Giovanni; Zanetti, Gianluigi
    In this paper we describe a method for the reconstruction and visualization of functional models of monkey brains. Models are built through the registration of high resolution images obtained from the scanning of histological sections with reference photos taken during the brain slicing. From the histological sections it is also possible to acquire specifically activated neuron coordinates introducing functional information in the model. Due to the specific nature of the images (texture information is useless and the sections could be deformed when they were cut and placed on glass) we solved the registration problem by extracting corresponding cerebral cortex borders (extracted with a snake algorithm), and computing from their deformation an image transform modeled as an affine deformation plus a non-linear field evaluated as an elastically constrained deformation minimizing contour distances. Registered images and contours are used then to build 3D models of specific brains by a software tool allowing the interactive visualization of cortical volumes together with the spatially referenced neurons classified and differently colored according to their functionalities.
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    A holographic collaborative medical visualization system
    (IOS, 2006-01) Bettio, Fabio; Frexia, Francesca; Giachetti, Andrea; Gobbetti, Enrico; Pintore, Giovanni; Zanetti, Gianluigi; Balogh, Tibor; Forgacs, Tamas; Agocs, Tibor; Bouvier, Eric
    We report on our work on the development of a novel holographic display technology, capable of targeting multiple freely moving naked eye viewers, and of a demonstrator exploiting this technology to provide medical specialists with a truly interactive collaborative 3D environment for diagnostic discussions and/or pre-operative planning.
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    Advances in massive model visualization in the CYBERSAR project
    (Consorzio COMETA, 2009-02) Agus, Marco; Bettio, Fabio; Marton, Fabio; Zorcolo, Antonio; Pintore, Giovanni
    We provide a survey of the major results obtained within the CYBERSAR project in the area of massive data visualization. Despite the impressive improvements in graphics and computational hardware performance, interactive visualization of massive models still remains a challenging problem. To address this problem, we developed methods that exploit the programmability of latest generation graphics hardware, and combine coarse-grained multiresolution models, chunk-based data management with compression, incremental view-dependent level-of-detail selection, and visibility culling. The models that can be interactively rendered with our methods range from multi-gigabyte-sized datasets for general 3D meshes or scalar volumes, to terabyte-sized datasets in the restricted 2.5D case of digital terrain models. Such a performance enables novel ways of exploring massive datasets. In particular, we have demonstrated the capability of driving innovative light field displays able of giving multiple freely moving naked-eye viewers the illusion of seeing and manipulating massive 3D objects with continuous viewer-independent parallax.
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    An integrated environment for steroscopic acquisition, off-line 3D elaboration, and visual presentation of biological actions
    (IOS, 2001-01) Agus, Marco; Bettio, Fabio; Gobbetti, Enrico; Fadiga, Luciano
    We present an integrated environment for stereoscopic acquisition, off-line 3D elaboration, and visual presentation of biological hand actions. The system is used in neurophysiological experiments aimed at the investigation of the parameters of the external stimuli that mirror neurons visually extract and match on their movement related activity.
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    High-quality networked terrain rendering from compressed bitstreams
    (ACM, 2007-04) Bettio, Fabio; Gobbetti, Enrico; Marton, Fabio; Pintore, Giovanni
    We describe a compressed multiresolution representation and a client-server architecture for supporting interactive high quality remote visualization of very large textured planar and spherical terrains. Our approach incrementally updates a chunked level-of-detail BDAM hierarchy by using precomputed wavelet coefficient matrices decoded from a compressed bitstream originating from a thin server. The structure combines the aggressive compression rates of wavelet-based image representations with the ability to ensure overall geometric continuity for variable resolution views of planar and spherical terrains with no need for run-time stitching. The efficiency of the approach is demonstrated on a large scale interactive remote visualization of global and local terrains on ADSL networks. A library implementing an early version of this work has been incorporated into a widely distributed geo-viewing system with tens of thousands of clients.
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    Improving the digitization of shape and color of 3D artworks in a cluttered environment
    (IEEE, 2013-10) 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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    Recent results in rendering massive models on horizontal parallax-only light field displays
    (Consorzio COMETA, 2009-02) Agus, Marco; Bettio, Fabio; Marton, Fabio; Zorcolo, Antonio
    In this contribution, we report on specialized out-of-core multiresolution real-time rendering systems able to render massive surface and volume models on a special class of horizontal parallax-only light field displays. The displays are based on a specially arranged array of projectors emitting light beams onto a holographic screen, which then makes the necessary optical transformation to compose these beams into a continuous 3D view. The rendering methods employ state-of-the-art out-of-core multiresolution techniques able to correctly project geometries onto the display and to dynamically adapt model resolution by taking into account the particular spatial accuracy characteristics of the display. The programmability of latest generation graphics architectures is exploited to achieve interactive performance. As a result, multiple freely moving naked-eye viewers can inspect and manipulate virtual 3D objects that appear to them floating at fixed physical locations. The approach provides rapid visual understanding of complex multi-gigabyte surface models and volumetric data sets.
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    Three-dimensional reconstruction and visualization of the cerebral cortex in primates
    (Springer, 2001-05) Demelio, Sergio; Bettio, Fabio; Gobbetti, Enrico; Luppino, Giuseppe
    We present a prototype interactive application for the direct analysis in three dimensions of the cerebral cortex in primates. The paper provides an overview of the current prototype system and presents the techniques used for reconstructing the cortex shape from data derived from histological sections as well as for rendering it at interactive rates. Results are evaluated by discussing the analysis of the right hemisphere of the brain of a macaque monkey used for neuroanatomical tract-tracing experiments.