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Now showing 1 - 7 of 7
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    Surfel Octrees: A New Scheme for Interactive Inspection of Anatomy Atlases in Client-Server Applications
    (The Eurographics Association, 2015) Surinyac, Jordi; Brunet, Pere; Mateu Sbert and Jorge Lopez-Moreno
    Nowadays, an increasing interest on tele-medicine and tele-diagnostic solutions can be observed, with client/server architectures for remote inspection of volume image-based medical data which are becoming more and more popular. The use of portable devices is gradually spreading due to their portability and easy maintenance. In this paper, we present an efficient data model for segmented volume models based on a hierarchical data structure of surfels per anatomical structure. Surfel Octrees are compact enough for transmission through networks with limited bandwidth, and provide good visual quality in the client devices at a limited footprint. Anatomy atlases are represented as octree forests, supporting local interaction in the client device and selection of groups of medical organs. After presenting the octree generation and interaction algorithms, we present several examples and discuss the interest of the proposed approach in low-end devices such as mobiles and tablets.
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    A New Approach for Perceptually-based Fitting Strokes into Straight Segments
    (The Eurographics Association, 2015) Plumed, Raquel; Company, Pedro; Varley, Peter A. C.; Mateu Sbert and Jorge Lopez-Moreno
    Fitting the strokes of a sketch into geometrical primitives is still an open problem, even for sketches which depict bare line-drawings without annotations. Such sketches comprise only discrete strokes, sequences of points obtained between a pen down and a pen up. It is commonly accepted that the best perceptual fittings depend on the context. Hence, we will only be able to extract the best line-drawing from a sketch by considering a complex recognition flow, where lines must be iteratively fitted according to different tentative relationships until the most plausible line-drawing is reached. The recognition task considered in this paper is determining whether a stroke represents a straight line. The goal is doing it in a way that allows for iterative recognition flows. The novel contributions are that our approach is more fast and robust than accurate, uses perceptual criteria to classify strokes, and returns likeliness instead of a simple yes/no.
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    PREFR: A Flexible Particle Rendering Framework
    (The Eurographics Association, 2015) Galindo, Sergio E.; Toharia, Pablo; Lopez-Moreno, Jorge; Robles, Oscar D.; Pastor, Luis; Mateu Sbert and Jorge Lopez-Moreno
    We present PREFR (Particle REndering FRamework): a first approach to a general-purpose particle rendering framework on the standard OpenGL architecture, designed with the goal of being easily configured by the user without compromising efficiency. In this paper, we analyze and discuss the performance of each stage involved in particle rendering in order to improve its efficiency for future versions with additional GPGPU computation steps or multicore parallelization techniques. Finally, we show the potential of our particle engine by tackling two very different problems: The rendering of neuronal electrical impulses in physiological models of the human brain, and the visualization of emergent patterns for information analysis, specifically emphasizing structured information in a complex data set.
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    Mobile Multiview Diffuse Texture Extraction
    (The Eurographics Association, 2015) Kán, Peter; Kaufmann, Hannes; Andrea Giachetti and Silvia Biasotti and Marco Tarini
    This paper presents a novel method for diffuse texture extraction from a set of multiview images. We address the problem of specularities removal by pixel value minimization across multiple automatically aligned input images. Our method is based on the fact that the presence of specular reflection only increases the captured pixel value. Moreover, we propose an algorithm for estimation of material region in the image by optimization on the GPU. Previous methods for diffuse component separation from multiple images require a complex hardware setup. In contrast to that, our method is highly usable because only a mobile phone is needed to reconstruct diffuse texture in an environment with arbitrary lighting. Moreover, our method is fully automatic and besides capturing of images from multiple viewpoints it does not require any user intervention. Many fields can benefit from our method, particularly material reconstruction, image processing, and digital content creation.
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    Efficient and Robust Position-Based Fluids for VFX
    (The Eurographics Association, 2015) Alduán, Iván; Tena, Angel; Otaduy, Miguel A.; Mateu Sbert and Jorge Lopez-Moreno
    Designing a fluid simulator with VFX production pipelines in mind is a difficult task where goals like efficiency, robustness and scalability compromise each other. Many impressive fluid simulation methods have been presented in research papers before, but often they do not meet the production and flexibility demands of artists working on actual VFX production pipelines. In this paper we present a particle-based fluid simulation framework, based on the well known Position-Based Fluids (PBF) method, designed to address VFX production demands. Our framework puts special care on data structure design and implementation details. It highlights cache-efficient GPU-friendly data structures, an improved Z-index sort spatial voxelization technique, tuned-up simulation algorithms, and collision treatment based on VDB fields. Altogether, they empower the artist with a very efficient fluid solver, but also with the robustness and versatility needed for simulating very diverse scenes and effects.
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    NeuroScheme: Efficient Multiscale Representations for the Visual Exploration of Morphological Data in the Human Brain Neocortex
    (The Eurographics Association, 2015) Pastor, Luis; Mata, Susana; Toharia, Pablo; Bayona, Sofia; Brito, Juan Pedro; Garcia-Cantero, Juan Jose; Mateu Sbert and Jorge Lopez-Moreno
    The analysis of data sets from such a complex domain as neuroscience is severely hampered by the brain complexity and by the huge amount of data originated in current experiments and simulations. The complexity of the brain stems not only from the enormous number of relevant entities that integrate it (for example, around 10
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    Tiled Projection Onto Deforming Screens
    (The Eurographics Association, 2015) Kim, Hyosun; Schinko, Christoph; Havemann, Sven; Redi, Ivan; Redi, Andrea; Fellner, Dieter W.; Rita Borgo and Cagatay Turkay
    For the next generation of visual installations it will not be sufficient to surround the visitor by stunning responsive audiovisual experiences - the next step is that space itself deforms in response to the user or user groups. Dynamic reconfigurable spaces are a new exciting possibility to influence the behaviour of groups and individuals; they may have the potential of stimulating various different social interactions and behaviours in a user-adapted fashion. However, some technical hurdles must be overcome. Projecting on larger surfaces, like a ceiling screen of 6 8 meters, is typically possible only with a tiled projection, i.e., with multiple projectors creating one large seamless image. This works well with a static ceiling; however, when the ceiling dynamically moves and deforms, the tiling becomes visible since the images no longer match. In this paper we present a method that can avoid such artifacts by dynamically adjusting the tiled projection to the deforming surface. Our method is surprisingly simple and efficient, and it does not require any image processing at runtime, nor any 3D reconstruction of the surface at any point.