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Now showing 1 - 7 of 7
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    Two Examples of GPGPU Acceleration of Memory-intensive Algorithms
    (The Eurographics Association, 2010) Marras, Stefano; Mura, Claudio; Gobbetti, Enrico; Scateni, Riccardo; Scopigno, Roberto; Enrico Puppo and Andrea Brogni and Leila De Floriani
    The advent of GPGPU technologies has allowed for sensible speed-ups in many high-dimension, memory-intensive computational problems. In this paper we demonstrate the e ectiveness of such techniques by describing two applications of GPGPU computing to two di erent subfields of computer graphics, namely computer vision and mesh processing. In the first case, CUDA technology is employed to accelerate the computation of approximation of motion between two images, known also as optical flow. As for mesh processing, we exploit the massivelyparallel architecture of CUDA devices to accelerate the face clustering procedure that is employed in many recent mesh segmentation algorithms. In both cases, the results obtained so far are presented and thoroughly discussed, along with the expected future development of the work.
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    A Practical Vision Based Approach to Unencumbered Direct Spatial Manipulation in Virtual Worlds
    (The Eurographics Association, 2007) Bettio, Fabio; Giachetti, Andrea; Gobbetti, Enrico; Marton, Fabio; Pintore, Giovanni; Raffaele De Amicis and Giuseppe Conti
    We present a practical approach for developing interactive environments that allows humans to interact with large complex 3D models without them having to manually operate input devices. The system provides support for scene manipulation based on hand tracking and gesture recognition and for direct 3D interaction with the 3D models in the display space if a suitably registered 3D display is used. Being based on markerless tracking of a user's two hands, the system does not require users to wear any input or output devices. 6DOF input is provided by using both hands simultaneously,making the tracker more robust since only tracking of position information is required. The effectiveness of the method is demonstrated with a simple application for model manipulation on a large stereo display, in which rendering constraints are met by employing state-of-the-art multiresolution techniques.
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    Towards Advanced Volumetric Display of the Human Musculoskeletal System
    (The Eurographics Association, 2008) Agus, Marco; Giachetti, Andrea; Gobbetti, Enrico; Guitián, José Antonio Iglesias; Marton, Fabio; Vittorio Scarano and Rosario De Chiara and Ugo Erra
    We report on our research results on effective volume visualization techniques for medical and anatomical data. Our volume rendering approach employs GPU accelerated out-of-core direct rendering algorithms to fully support high resolution, 16 bits, raw medical datasets as well as segmentation. Images can be presented on a special light field display based on projection technology. Human anatomical data appear to moving viewers floating in the light field display space and can be interactively manipulated.
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    Edge Adaptive and Energy Preserving Volume Upscaling for High Quality Volume Rendering
    (The Eurographics Association, 2010) Giachetti, Andrea; Guitián, J. A. Iglesias; Gobbetti, Enrico; Enrico Puppo and Andrea Brogni and Leila De Floriani
    We describe an edge-directed optimization-based method for volumetric data supersampling. The method is based on voxel splitting and iterative refinement performed with a greedy optimization driven by the smoothing of second order gray level derivatives and the assumption that the average gray level in the original voxels region cannot change. Due to these assumptions, the method, which is the 3D extension of a recently proposed technique, is particularly suitable for upscaling medical imaging data creating physically reasonable voxel values and overcoming the so-called partial volume effect. The good quality of the results obtained is demonstrated through experimental tests. Furthermore, we show how offline 3D upscaling of volumes can be coupled with recent techniques to perform high quality volume rendering of large datasets, obtaining a better inspection of medical volumetric data
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    Medical Visualization with New Generation Spatial 3D Displays
    (The Eurographics Association, 2007) Agus, Marco; Bettio, Fabio; Gobbetti, Enrico; Pintore, Giovanni; Raffaele De Amicis and Giuseppe Conti
    In this paper the capabilities of a modern spatial 3D display are exploited for medical visualization tasks. The systemgives multiple viewers the illusion of seeing virtual objects floating at fixed physical locations. The usage of this kind of display in conjunction with 3D visualization techniques helps disambiguating complex images, so it is proven to be a real advantage for immediate understanding and visualization of medical data.We demonstrate this by reporting on some preliminary test cases of direct volume rendering techniques (Maximum Intensity Projection and X Ray simulation), as well as an example of a collaborative medical diagnostic application for analysis of Abdominal Aortic Aneurysms.
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    Visual Enhancements for Improved Interactive Rendering on Light Field Displays
    (The Eurographics Association, 2011) Agus, Marco; Pintore, Giovanni; Marton, Fabio; Gobbetti, Enrico; Zorcolo, Antonio; Andrea F. Abate and Michele Nappi and Genny Tortora
    Rendering of complex scenes on a projector-based light field display requires 3D content adaptation in order to provide comfortable viewing experiences in all conditions. In this paper we report about our approach to improve visual experiences while coping with the limitations in the effective field of depth and the angular field of view of the light field display. We present adaptation methods employing non-linear depth mapping and depth of field simulation which leave large parts of the scene unmodified, while modifying the other parts in a non-intrusive way. The methods are integrated in an interactive visualization system for the inspection of massive models on a large scale 35MPixel light field display. Preliminary results of subjective evaluation demonstrate that our rendering adaptation techniques improve visual comfort without affecting the overall depth perception.
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    An Application of Multiresolution Massive Surface Representations to the Simulation of Asteroid Missions
    (The Eurographics Association, 2010) Pintore, Giovanni; Combet, Roberto; Gobbetti, Enrico; Marton, Fabio; Turner, Russell; Enrico Puppo and Andrea Brogni and Leila De Floriani
    We report on a real-time application supporting fast, realistic real-time rendering of asteroid datasets, as well as collision detection and response between the asteroid and prototype robotic surface exploration vehicles. The system organizes the asteroid surface into a two-level multiresolution structure, which embeds a fine-grained perpatch spatial index within a coarse-grained patch-based structure. The coarse-grained structure, maintained out-of-core, is used for fast batched I/O and GPU accelerated rendering, while the per-patch fine-grained structure is used to accelerate raycasting and collision queries. The resulting system has been tested with a simple robot lander and surface exploration simulator. The system models gravity using mass particles uniformly distributed within the asteroid bodies. Real-time performance is achieved on a commodity platform with giga triangle representations of asteroids 25143 Itokawa and 433 Eros.