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Now showing 1 - 10 of 12
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    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.
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    A 3 Cent Recognizer: Simple and Effective Retrieval and Classification of Mid-air Gestures from Single 3D Traces
    (The Eurographics Association, 2017) Caputo, Fabio Marco; Prebianca, Pietro; Carcangiu, Alessandro; Spano, Lucio D.; Giachetti, Andrea; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    In this paper we present a simple 3D gesture recognizer based on trajectory matching, showing its good performances in classification and retrieval of command gestures based on single hand trajectories. We demonstrate that further simplifications in porting the classic "1 dollar" algorithm approach from the 2D to the 3D gesture recognition and retrieval problems can result in very high classification accuracy and retrieval scores even on datasets with a large number of different gestures executed by different users. Furthermore, recognition can be good even with heavily subsampled path traces and with incomplete gestures.
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    3D Reconstruction of Facade and the Statues of the Church ''Maria Santissima dell'Elemosina'' in Biancavilla
    (The Eurographics Association, 2017) Tomasello, Simone Federico; Pazzi, Miriam Caterina; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    3D modelling plays a key role in the reconstruction of cultural heritage assets. It allows to give an idea of the original condition of a cultural heritage before time and weathering effects. This paper presents the 3D reconstruction of the church ''Maria Santissima dell'Elemosina'' through various software for modelling, as well as the acquisition and processing of elements. High resolution photos has been employed for faithful reproduction of the models details.
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    Perimeter Detection in Sketched Drawings of Polyhedral Shapes
    (The Eurographics Association, 2017) Company, Pedro; Varley, Peter A. C.; Plumed, Raquel; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    This paper describes a new "envelope" approach for detecting object perimeters in line-drawings vectorised from sketches of polyhedral objects. Existing approaches for extracting contours from digital images are unsuitable for Sketch-Based Modelling, as they calculate where the contour is, but not which elements of the line-drawing belong to it. In our approach, the perimeter is described in terms of lines and junctions (including intersections and T-junctions) of the original line drawing.
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    Smart Tools and Applications in computer Graphics - Eurographics Italian Chapter Conference 2017: Frontmatter
    (Eurographics Association, 2017) Giachetti, Andrea; Pingi, Paolo; Stanco, Filippo; Andrea Giachetti and Paolo Pingi and Filippo Stanco
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    A Digital Approach for the Study of Roman Signacula From Syracuse, Sicily
    (The Eurographics Association, 2017) Tanasi, Davide; Milotta, Filippo L. M.; Gradante, Ilenia; Stanco, Filippo; Kaplan, Howard; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    In the last decade the epigraphists have grown a new interest in signacula, a class of artifacts for a long time neglected. This has brought numerous contributions devoted to the different regional contexts, along with reflections on methodological questions, not to mention the momentum towards the digitizing of a corpus which counts at least 3,500 pieces, confirming the great potential of these artifacts in providing information related not only to the economy and to the administration of the ''res'', both in public and private sphere, but also about the profile of the signacula holders. In this scenario, a specific research question has been inspired by the Sicilian seals - about 60 signacula and a dozen impressions left by seals on mortar in burial contexts: it is possible to identify unequivocally a signaculum through its impression? Given for granted that the use of 3D documentation will bring along effective results in terms of improved readability of signacula and seals, the aim of this contribute is to establish a protocol for a semi-automatic matching between 3D models of seals and 3D models of impressions. As part of a preliminary scanning campaign of Late Roman impressions on mortars and metal seals from the catacombs of Syracuse, two bronze metal seals were digitized with a NextEngine 3D triangulation laser scanner and subsequently 3D printed with liquid resin with a Formlabs Form 2 SLA high resolution printer. The casts obtained, were experimentally used to create a set of impressions on mortar using different degrees and angles of pressure, in order to create similar but still different stamps. During the next step, the impressions were 3D scanned and used as ground truth for the outlined semi-automatic procedure of matching with the seals. In MeshLab environment, the 3d models of seals and impressions were manually aligned and then the distance between two sets of 3D points was measured using the filter Hausdorff distance in order to validate a matching. This successful exercise could open the way to the proposal of creating a virtual edition of signacula with 3D models metadata. Furthermore, a research agenda may include the design of a machine learning algorithm for matching of 3D meshes.
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    A Seamless Pipeline for the Acquisition of the Body Shape: the Virtuoso Case Study
    (The Eurographics Association, 2017) Saba, Marianna; Sorrentino, Fabio; Muntoni, Alessandro; Casti, Sara; Cherchi, Gianmarco; Carcangiu, Alessandro; Corda, Fabrizio; Murru, Alessio; Spano, Lucio Davide; Scateni, Riccardo; Vitali, Ilaria; Salvetti, Ovidio; Magrini, Massimo; Villa, Andrea; Carboni, Andrea; Pascali, Maria Antonietta; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    In this paper, we describe the design and the implementation of the demonstrator for the Virtuoso project, which aims at creating seamless support for fitness and wellness activities in touristic resort.We define the objectives of the user interface, the hardware and software setup, showing how we combined and exploited consumer-level devices for supporting 3D body scan, contact-less acquisition of physical parameters, exercise guidance and operator support.
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    Polycube-based Decomposition for Fabrication
    (The Eurographics Association, 2017) Fanni, Filippo A.; Cherchi, Gianmarco; Scateni, Riccardo; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    In recent years, fabrication technologies developed at a very fast pace. However, some limitations on shape and dimension still apply both to additive and subtractive manufacturing, and one way to bypass them could be the subdivision of the object to build. We present here a simple algorithm, based on the polycube representation of the original shape, able to decompose any model into simpler portions that are better fabricable. The shape is first mapped in a polycube and, then, split to take advantage of the simple polycube subdivision, thus having, quite easily, a partition of the model at hand. The main aim of this work is to study and analyse pros and cons of this simple subdivision scheme for fabrication, in view of using both the additive and subtractive pipelines. The proposed subdivision scheme is computationally light and it produces quite good results, especially when it is applied to models that can be easily decomposed in a small collection of cuboids. The obtained subdivisions are suitable for 3D printing.
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    Visual Analysis of Glycogen Derived Lactate Absorption in Dense and Sparse Surface Reconstructions of Rodent Brain Structures
    (The Eurographics Association, 2017) Calì, Corrado; Agus, Marco; Gagnon, Nicholas; Hadwiger, Markus; Magistretti, Pierre J.; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    Astrocytes are the most abundant type of glial cells of the central nervous system; their involvement in brain functioning, from synaptic to network level, is to date a matter of intense research. A well-established function of astroglial cells, among others, is the metabolic support of neurons. Recently, it has been shown that during tasks like learning and long-term memory formation, synapses sustain their metabolic needs using lactate, a compound that astrocytes can synthesize from glycogen, a molecule that stores glucose, rather than glucose itself. Aforementioned role of astrocytes, as energy reservoir to neurons, is challenging the classic paradigms of neuro-energetic research. Understanding their morphology at nano-scale resolution is therefore a fundamental research challenge with enormous implications on many branches of neuroscience research, such as the study of neuro-degenerative and cognitive disorders. Here, we present an illustrative visualization technique customized for the analysis of the interaction of astrocytic glycogen on surrounding neurites in order to formulate hypotheses on the energy absorption mechanisms. The method integrates a high-resolution surface reconstruction of neurites and the energy sources in form of glycogen granules, and computes an absorption map according to a radiance transfer mechanism. The technique is built on top of a framework for processing and rendering triangulated surface models, and it is used for real-time 3D exploration and inspection of the neural structures paired with the energy sources. The resulting visual representation provides an immediate and comprehensible illustration of the areas in which the probability of lactate shuttling is higher. This method has been further employed for testing neuroenergetics hypotheses about the utilization of glycogen during synaptic development.
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    The Social Picture: Advanced Image Analysis Applications
    (The Eurographics Association, 2017) Milotta, Filippo L. M.; Bellocchi, Michele; Battiato, Sebastiano; Andrea Giachetti and Paolo Pingi and Filippo Stanco
    In The Social Picture (TSP) an huge amount of crowdsourced social images can be collected and explored. We distinguish three main kind of events: public, private and cultural heritage related ones. The framework embeds a number of advanced Computer Vision algorithms, able to capture the visual content of images and organize them in a semantic way. In this paper we employ VisualSFM (VSFM) to add new features in TSP through the computation of a 3D sparse reconstruction of a collection within TSP. VisualSFM creates a N-View Match (NVM) file as output. Starting from this NVM file, which characterizes the 3D sparse reconstruction, we are able to build two important relationships: the one between cameras and points and the one between cameras themselves. Using these relationships, we implemented two advanced Image Analysis applications. In the first one, we consider the cameras as nodes in a fully connected graph in which the edges weights are equal to the number of matches between cameras. The spanning tree of this graph is used to explore images in a meaningful way, obtaining a scene summarization. In the second application, we define three kinds of density maps with relation to image features: density map, weighted-density map and social-weighted-density map. Results of a test conducted on a collection from TSP is shown.