CRS4

URI permanente di questa Community

https://hdl.handle.net/11050/2
Fondato negli anni '90, il CRS4 è un centro di ricerca interdisciplinare che promuove lo studio, lo sviluppo e l'applicazione di soluzioni innovative a problemi provenienti da ambienti naturali, sociali e industriali. Tali sviluppi e soluzioni si basano sulla Scienza e Tecnologia dell'Informazione e sul Calcolo Digitale ad alte prestazioni. L'obiettivo principale è l'Innovazione.

La missione del Centro è quella di aiutare la Sardegna a dar vita e far crescere un tessuto di imprese hi-tech essenziali per il suo sviluppo economico e culturale.

Dal 2010 il Centro occupa circa 200 persone, tra ricercatori, tecnologi e staff di supporto, che operano in 4 settori strategici della ricerca scientifica: Biomedicina, Data Fusion, Energia e Ambiente e Società dell'Informazione. Il CRS4, inoltre, gestisce uno dei principali centri di calcolo italiani, la prima piattaforma in Italia dedicata alla genotipizzazione e al sequenziamento massivo del DNA e un laboratorio di Visual Computing allo stato dell'arte.

Sito istituzionale del CRS4

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Mostra il contenuto di CRS4 per Subject "3D model"

Ora in mostra 1 - 9 di 9
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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 distributed heterogeneous image server
    (1998) Loddo, Sergio; Brelstaff, Gavin; Zanetti, Gianluigi
    Digital image transmission is now ubiquitous across computer networks and thus there is increasing pressure to allow access to medical image data at sites remote from PACS locations. In fact, it may soon make economic sense to outsource medical image services - to dedicated service providers at geographical locations outside of the traditional radiology department or HIS’s. The technical challenge faced by system developers is to produce client-Viewer/server-PACS configurations that can realistically span the network. In particular, the systems must provide the performance usually expected by client medics and it must be flexible to the needs of the service providers. At CRS4 - BioMedical Applications - we are integrating various technologies derived from the www-intranet field, and object-oriented middleware to prototype technological solutions that address both the issues of performance and flexibility. These are discussed in turn below; then we provide an overview of our system.
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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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    Creating and presenting real and artificial visual stimuli for the neurophysiological investigation of the observation/execution matching system
    (2000-06) Agus, Marco; Bettio, Fabio; Gobbetti, Enrico
    Recent neurophysiological experiments have shown that the visual stimuli that trigger a particular kind of neurons located in the ventral premotor cortex of monkeys and humans are very selective. These textitmirror neurons are activated when the hand of another individual interacts with an objects but are not activated when the actions, identical in purpose, are made by manipulated mechanical tools. A Human Frontiers Science Program project is investigating which are the parameters of the external stimuli that mirror neurons visually extract and match on their movement related activity. The planned neurophysiological experiments will require the presentation of digital stimuli of different kinds, including video sequences showing meaningful actions made by human hands, synthetic reproductions of the same actions made by realistic virtual hands, as well as variations of the same actions by controlled modifications of hand geometry and/or action kinematics. This paper presents the specialized animation system we have developed for the project.
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    Exploring virtual prototypes using time-critical rendering
    (1999-11) Gobbetti, Enrico; Scateni, Riccardo; Agus, Marco
    We present an application of our time-critical multiresolution rendering algorithm to the visual and possibly collaborative exploration of large digital mock-ups. Our technique relies upon a scene description in which objects are represented as multiresolution meshes. We perform a constrained optimization at each frame to choose the resolution of each potentially visible object that generates the best quality image while meeting timing constraints. We present numerical and pictorial results of the experiments performed that support our claim that we can maintain a xed frame-rate even when rendering very large datasets on low-end graphics PCs.
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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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    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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    Three-dimensional graphics
    (Wiley, 1999-02) Gobbetti, Enrico; Scateni, Riccardo
    Three-dimensional graphics is the area of computer graphics that deals with producing two-dimensional representations, or images, of three-dimensional synthetic scenes, as seen from a given viewing configuration. The level of sophistication of these images may vary from simple wire-frame representations, where objects are depicted as a set of segment lines, with no data on surfaces and volumes, to photorealistic rendering, where illumination effects are computed using the physical laws of light propagation. All the different approaches are based on the metaphor of a virtual camera positioned in 3D space and looking at the scene. Hence, independently from the rendering algorithm used, producing an image of the scene always requires the resolution of the following problems: 1. Modeling geometric relationships among scene objects, and in particular efficiently representing the situation in 3D space of objects and virtual cameras; 2. Culling and clipping, i.e. efficiently determining which objects are visible from the virtual camera; 3. Projecting visible objects on the film plane of the virtual camera in order to render them. This chapter provides an introduction to the field by presenting the standard approaches for solving the aforementioned problems.
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    Virtual sardinia: a hypermedia fly-through with real data
    (1995) Gobbetti, Enrico; Leone, Andrea O.; Marini, Alberto
    The Virtual Sardinia project aims at collecting a large amount of heterogeneous data concerning the island of Sardinia and representing them in such a way that a casual user can easily navigate through them in a virtual trip. All these data are interconnected in an hypermedia way, browsable in the World-wide Web, ranging from geographic to archaeological data, from historical to touristical info, both in 2D and 3D. The central component of Virtual Sardinia is i3D, a high-speed 3D scene viewer for the World-wide Web. Using a Spaceball, the user can intuitively navigate with continuous viewpoint control inside three-dimensional data, while selecting 3D objects with the mouse triggers requests for access to remote media documents that can be distributed over the Internet. For the Virtual Sardinia project, the main 3D model that is explored by the users is a three-dimensional reconstruction of the island of Sardinia built from a digital terrain model texture-mapped with satellite images.