Search Results

Now showing 1 - 10 of 198
  • Item
    Multi-modal Digitalization of Cultural Heritage Artifacts
    (The Eurographics Association, 2014) Stanco, Filippo; Gallo, Giovanni; Cannata, Giovanna; Lombardo, Marcella; Andrea Giachetti
    Objects made of different media, paintings, marbles, clay and wooden objects, textiles etc., form the historical collections of most of the middle to medium sized Museums in Italy. This variety poses difficult challenges to these institutions when they face the digitalization of part of their patrimony. This paper provides a report of an ongoing inter-disciplinary experimental program for a digitalization effort to be carried out by one of such institution. Through the discussion of the digitalization of different objects obtained with the use and integration of different techniques we illustrate some of the lessons learned in transferring to the final intended users the graphical tools and the know-how previously acquired in a research laboratory.
  • Item
    Automatic Generation of Synthetic Retinal Fundus Images
    (The Eurographics Association, 2014) Fiorini, S.; Biasi, M. De; Ballerini, L.; Trucco, E.; Ruggeri, A.; Andrea Giachetti
    This study aims to generate synthetic and realistic retinal fundus colour images, similar in characteristics to a given dataset, as well as the values of all morphological parameters. A representative task could be, for example, the synthesis of a retinal image with the corresponding vessel tree and optic nerve head binary map, measurement of vessel width in any position, fovea localisation and so on. The presented paper describes the techniques developed for the generation of both vascular and non-vascular regions (i.e. retinal background, fovea and optic disc). To synthesise convincing retinal backgrounds and foveae, a patch-based algorithm has been developed; model-based texture synthesis techniques have also been implemented for the generation of realistic optic discs and vessel networks. The validity of our synthetic retinal images has been demonstrated by visual inspection and quantitative experiments.
  • Item
    Tracking the Evolution of Rainfall Precipitation Fields Using Persistent Maxima
    (The Eurographics Association, 2016) Biasotti, Silvia; Cerri, Andrea; Pittaluga, Simone; Sobrero, Davide; Spagnuolo, Michela; Giovanni Pintore and Filippo Stanco
    In this paper we propose a novel methodology for tracking the maxima of rainfall precipitation fields, whose changes in time may give interesting insights on the evolution of storm. Our approach is based on a topological analysis of rainfall data allowing for the extraction of the most prominent, and hence meaningful, rainfall field maxima. Then, an ad-hoc bottleneck matching is used to track the evolution of maxima along multiple time instances. The potential of our method is exhibited through a set of experiments carried out on a collection of observed punctual rainfall data and radar measurements provided by Genova municipality and Regione Liguria.
  • Item
    Selective Rasterized Ray-traced Reflections on the GPU
    (The Eurographics Association, 2016) Kastrati, Mattias Frid; Goswami, Prashant; Giovanni Pintore and Filippo Stanco
    Ray-tracing achieves impressive effects such as realistic reflections on complex surfaces but is also more computationally expensive than classic rasterization. Rasterized ray-tracing methods can accelerate ray-tracing by taking advantage of the massive parallelization available in the rasterization pipeline on the GPU. In this paper, we propose a selective rasterized raytracing method that optimizes the rasterized ray-tracing by selectively allocating computational resources to reflective regions in the image. Our experiments suggest that the method can speed-up the computation by up to 4 times and also reduce the memory footprint by almost 66% without affecting the image quality. We demonstrate the effectiveness of our method using complex scenes and animations.
  • Item
    The use of Virtual Reality in preserving and reactivating immersive audio art installations: the case of Dissonanze Circolari by Roberto Taroni
    (The Eurographics Association, 2024) Russo, Alessandro; Fayyaz, Nikoo; Franceschini, Andrea; Caputo, Ariel; Garro, Valeria; Giachetti, Andrea; Castellani, Umberto; Dulecha, Tinsae Gebrechristos
    Interactive multimedia artworks pose unique challenges for their preservation, such as the obsolescence of original components, software, and playback devices, and other issues related to their interactive and time-based nature. The Centro di Sonologia Computazionale (CSC) of the University of Padova developed the Multilevel Dynamic Preservation (MDP) model, which aims at ensuring the long-term preservation of multimedia artworks by treating them as dynamic objects. Reactivation is a fundamental step for allowing their preservation, and, among various reactivation strategies, Virtual Reality (VR) provides a unique opportunity to recreate the immersive experience while still maintaining the concept of the original artwork. The CSC started to work together with Italian artist Roberto Taroni, a central figure in the experimental scenario, who often combined music and visual arts in his works. This contribution concerns the reactivation in VR of Roberto Taroni's artwork ''Dissonanze Circolari'' from 1999. This installation featured a room with 16 speakers, each one playing a fragment of Beethoven's piano performance, Op.111, executed by different musicians, creating a dissonance-based immersive experience. The reactivation was carried out using the documentation provided by the artist and the audio samples from the original installation. The VR environment was created using the game engine Unreal Engine 5. This reactivation approach allows to maximize access to the artwork, providing new information for curators, scholars, and art enthusiasts.
  • Item
    User Interaction Feedback in a Hand-Controlled Interface for Robot Team Tele-operation Using Wearable Augmented Reality
    (The Eurographics Association, 2017) Cannavò, Alberto; Lamberti, Fabrizio; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    Continuous advancements in the field of robotics and its increasing spread across heterogeneous application scenarios make the development of ever more effective user interfaces for human-robot interaction (HRI) an extremely relevant research topic. In particular, Natural User Interfaces (NUIs), e.g., based on hand and body gestures, proved to be an interesting technology to be exploited for designing intuitive interaction paradigms in the field of HRI. However, the more sophisticated the HRI interfaces become, the more important is to provide users with an accurate feedback about the state of the robot as well as of the interface itself. In this work, an Augmented Reality (AR)-based interface is deployed on a head-mounted display to enable tele-operation of a remote robot team using hand movements and gestures. A user study is performed to assess the advantages of wearable AR compared to desktop-based AR in the execution of specific tasks.
  • Item
    A Virtual Character Posing System based on Reconfigurable Tangible User Interfaces and Immersive Virtual Reality
    (The Eurographics Association, 2018) Cannavò, A.; Lamberti, F.; Livesu, Marco and Pintore, Gianni and Signoroni, Alberto
    Computer animation and, particularly, virtual character animation, are very time consuming and skill-intensive tasks, which require animators to work with sophisticated user interfaces. Tangible user interfaces (TUIs) already proved to be capable of making character animation more intuitive, and possibly more efficient, by leveraging the affordances provided by physical props that mimic the structure of virtual counterparts. The main downside of existing TUI-based animation solutions is the reduced accuracy, which is due partly to the use of mechanical parts, partly to the fact that, despite the adoption of a 3D input, users still have to work with a 2D output (usually represented by one or more views displayed on a screen). However, output methods that are natively 3D, e.g., based on virtual reality (VR), have been already exploited in different ways within computer animation scenarios. By moving from the above considerations and by building upon an existing work, this paper proposes a VR-based character animation system that combines the advantages of TUIs with the improved spatial awareness, enhanced visualization and better control on the observation point in the virtual space ensured by immersive VR. Results of a user study with both skilled and unskilled users showed a marked preference for the devised system, which was judged as more intuitive than that in the reference work, and allowed users to pose a virtual character in a lower time and with a higher accuracy.
  • Item
    An Approach to the Decomposition of Solids with Voids via Morse Theory
    (The Eurographics Association, 2023) Pareja-Corcho, Juan; Montoya-Zapata, Diego; Moreno, Aitor; Cadavid, Carlos; Posada, Jorge; Arenas-Tobon, Ketzare; Ruiz-Salguero, Oscar; Banterle, Francesco; Caggianese, Giuseppe; Capece, Nicola; Erra, Ugo; Lupinetti, Katia; Manfredi, Gilda
    The decomposition of solids is a problem of interest in areas of engineering such as feature recognition or manufacturing planning. The problem can be stated as finding a set of smaller and simpler pieces that glued together amount to the initial solid. This decomposition can be guided by geometrical or topological criteria and be applied to either surfaces or solids (embedded manifolds). Most topological decompositions rely on Morse theory to identify changes in the topology of a manifold. A Morse function f is defined on the manifold and the manifold's topology is studied by studying the behaviour of the critical points of f . A popular structure used to encode this behaviour is the Reeb graph. Reeb graph-based decompositions have proven to work well for surfaces and for solids without inner voids, but fail to consider solids with inner voids. In this work we present a methodology based on the handle-decomposition of a manifold that can encode changes in the topology of solids both with and without inner voids. Our methodology uses the Boundary Representation of the solid and a shape similarity criteria to identify changes in the topology of both the outer and inner boundary(ies) of the solid. Our methodology is defined for Morse functions that produce parallel planar level sets and we do not consider the case of annidated solids (i.e. solids within other solids). We present an algorithm to implement our methodology and execute experiments on several datasets. Future work includes the testing of the methodology with functions different to the height function and the speed up of the algorithm's data structure.
  • Item
    HIJSON: Cartographic Document for Web Modeling of Interactive Indoor Mapping
    (The Eurographics Association, 2015) Spini, Federico; Sportillo, Marco; Virgadamo, Marco; Marino, Enrico; Bottaro, Antonio; Paoluzzi, Alberto; Andrea Giachetti and Silvia Biasotti and Marco Tarini
    This paper introduces HIJSON, a novel indoor cartographic document format with several enhancements. The document is generated using LAR (Linear Algebraic Representation), so allowing for cellular complexes with general topology and shape. A software framework FIVE is also presented, that relies on HIJSON documents and is entirely based on web technologies. With respect to current cartographic formats, HIJSON suggests four major enhancements: (a) exposes a hierarchical structure; (b) uses local metric coordinate systems; (c) may import external geometric models; (d) accepts semantic extensions. The semantic extensions supported by the FIVE framework architecture encapsulate the details about communication protocols, rendering style, and exchanged and displayed information, allowing the HIJSON format to be extended with any sort of models of objects, sensors or behaviors.
  • Item
    Extracting Ordered Iso-Geodesic Points on the Mesh
    (The Eurographics Association, 2020) Tortorici, Claudio; Werghi, Naoufel; Berretti, Stefano; Biasotti, Silvia and Pintus, Ruggero and Berretti, Stefano
    The mesh manifold is one of the most used modalities for representing 3D objects. Although it provides a fully connected not oriented structure, it has some drawback when compared to the grid of pixels of a still image. Indeed, mesh manifolds do not hold any order information, neither locally nor globally, which makes some operation computationally expensive or even impossible. To unleash its potential and to benefit from its capability of representing the 3D information, further advancements have to be made in order to allow basic operations (i.e., convolution) and effective descriptor extraction. In this paper, we present our preliminary study on a new approach to extract Iso-Geodesic points on a mesh manifold. The approach can be applied in various applications, from feature extraction, to convolution operation and mesh reconstruction. It also revealed to be robust to variations of mesh surface and tessellation, providing an effective geodesic distance approximation.