CEIG12

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https://diglib.eg.org/handle/10.2312/896

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Now showing 1 - 20 of 37
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    Analysis of Coded Apertures for Defocus Deblurring of HDR Images
    (The Eurographics Association, 2012) Garcia, Luis; Presa, Lara; Gutierrez, Diego; Masia, Belen; Isabel Navazo and Gustavo Patow
    In recent years, research on computational photography has reached important advances in the field of coded apertures for defocus deblurring. These advances are known to perform well for low dynamic range images (LDR), but nothing is written about the extension of these techniques to high dynamic range imaging (HDR). In this paper, we focus on the analysis of how existing coded apertures techniques perform in defocus deblurring of HDR images. We present and analyse three different methods for recovering focused HDR radiances from an input of blurred LDR exposures and from a single blurred HDR radiance, and compare them in terms of the quality of their results, given by the perceptual metric HDR-VDP2. Our research includes the analysis of the employment of different statistical deconvolution priors, made both from HDR and LDR images, performing synthetic experiments as well as real ones.
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    Uncertainty Visualization of Brain Fibers
    (The Eurographics Association, 2012) Hermosilla, Pedro; Brecheisen, Ralph; Vázquez, Pere-Pau; Vilanova, Anna; Isabel Navazo and Gustavo Patow
    Diffuse Tensor Imaging (DTI) is an acquisition method based on Magnetic Resonance (MR) that provides information on the white matter fiber pathways in the living human brain. Such knowledge is crucial for understanding the way different parts of the brain work and how they interact with each other. The reconstruction of fiber tracts, however, depends on a number of parameters that introduce a degree of uncertainty in the data. Together with the parameter setting, other elements such as noise, motion, partial volume effects, or image artifacts increase the uncertainty. Therefore, fiber tracking algorithms may produce misleading results. Visualizing such uncertainty is important to avoid taking wrong decisions in medical environments. In this paper we present a set of techniques that provide a better understanding on the visualization of brain fibers by means of textures, silhouettes, ambient occlusion, and animation.
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    PrimeSense Sensors as a Low-cost Method for Motion Capture on Clinical Tests
    (The Eurographics Association, 2012) Sanmartín, G.; Flores, J.; Arias, P.; Cudeiro, J.; Méndez, R.; Isabel Navazo and Gustavo Patow
    Virtual Reality (VR) is the computer recreation of simulated environments that create on the user a sense of physical presence. VR provides the advantages of being highly flexible and controllable, allowing experts to generate the optimal conditions for any given test and isolating any desired variables in the course of an experiment. An important feature of VR is that it allows interaction within the virtual world. Motion capture is one of the most popular technologies, because it contributes to creating in the subject the sense of presence. There are several methods to incorporate these techniques into an VR system, with the challenge of them not being too invasive. We propose a method using PrimeSense sensors and several computer vision techniques to build a low-cost system that has proven to be valid in its application as a support therapy for Parkinson's disease (PD) patients.
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    Ventricular Puncture Trainer
    (The Eurographics Association, 2012) Pandiella, Imanol Muñoz; Monclús, Eva; Brunet, Pere; Conesa, Gerard; Isabel Navazo and Gustavo Patow
    The learning process in neurosurgery is a large and difficult task based on experimentation, being ventriculostomy not an exception. We have developed a virtual reality system to help training novel surgeons on this kind of operation. The system consists of the simulation of the surgery using a haptic device and a subsequent 3D visual inspection of the surgical trajectory. Our main objective was to proof that the tactile sensation produced by our system was enough realistic for the surgeons. We carried out a demonstration session in a medical workshop where all surgeons attending the workshop used the system with a very enthusiastic response about the perception experimented through the system.
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    Computing Curvature Information on 3D Meshes from Cultural Heritage Artifacts
    (The Eurographics Association, 2012) López, L.; Torres, J. C.; Soler, F.; Isabel Navazo and Gustavo Patow
    The curvature provides essential information about the features of a object surface. This poster presents an operation that makes it possible to generate the curvature information in the CHiSEL system.
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    Non-rigid 3D Faces Registration using Geodesic Distance Maps
    (The Eurographics Association, 2012) Gurguí, T.; Poveda, F.; Martí, E.; Isabel Navazo and Gustavo Patow
    3D facial mesh registration is a key step in 3D facial analisys. This process calculates a mapping between faces in order to put in correspondence each point of both faces. In this poster we introduce a new approach for 3D face registration based in geodesical distances and 2D non-rigid registration.
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    Kinamo: Gait Analysis System
    (The Eurographics Association, 2012) Martínez, H.; Gil-Gómez, J. A.; Martínez-Gramage, J.; Juan, M. C.; Isabel Navazo and Gustavo Patow
    The gait analysis is a fundamental technique for functional assessment of patients with gait problems. This analysis is generally available to few patients because the systems needed to carry it out have a high cost. In this paper, we present a novel system, Kinamo, which allows to decrease drastically the cost when performing the gait analysis using Kinect cameras, which not only allows the reduction of cost, but also facilitates the acquisition conditions.
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    Bringing Direct Local Control to Interactive Visual Editing of Procedural Buildings
    (The Eurographics Association, 2012) Riu, Adria; Patow, Gustavo; Isabel Navazo and Gustavo Patow
    This paper presents a new system to add direct and persistent local control to the visual editing of rules for procedural buildings, avoiding a combinatorial explosion of grammar rules. In this paper we follow the ideas initially proposed by Lipp and co-workers [LWW08]. For this, we have added a few simple new commands, which are added to the artist-provided ruleset in a way completely transparent to the user. The end-user selects the primitives/assets to modify, and the system automatically incorporates these modifications into the ruleset. This change is performed using graph-rewriting techniques, which are both simple to define and control, but also very powerful and practical for these situations.
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    More Stable SPH-based Fluid Simulation
    (The Eurographics Association, 2012) Perea, Juan J.; Cordero, Juan M.; Isabel Navazo and Gustavo Patow
    The simulation of fluid is a field largely discussed, from the viewpoint of engineering, in the so-called computational fluid dynamics (CFD). A problem that occurs repeatedly in the literature of CFD is the stability of the simulation. One of the elements that introduce instability in any CFD model is the temporal integration method. Among the most commonly used CFD techniques, both in the field of engineering and in the computer graphics, is SPH, which is particularly relevant to its computational simplicity. However, this technique adds stability problems due to the treatment of viscous and pressure terms arising from the formulation of Navier'Stokes. SPH also introduces greater instability by the need to use interpolation functions appropriate to the phenomena that occur in fluid dynamics. We present solutions to these four problems of inestability mentioned: treatment of the terms of pressure and viscosity that appear in the Navier'Stokes, the formulation of the characteristic interpolation function of SPH and treatment of temporal integration.
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    Locating Companies in 3D Urban Environments on the Internet
    (The Eurographics Association, 2012) Estrella, Ana M. López; Ortega, M. Dolores Robles; Alvarado, Lidia Ortega; Higueruela, Francisco R. Feito; Isabel Navazo and Gustavo Patow
    3D visualization is being incorporated in a lot of fields, including Geographic Information Systems (GIS). In addition, the Internet is the most popular method to find information, due to its accessibility. For this reason, most companies and businesses are interested in showing their products on the Web to make them well-known to many people. Considering all these concepts, this paper explains the process of developing a web application prototype with some GIS features. The main goal is to obtain business information, the location and the 2.5D navigation in an urban environment. In this way, through a web browser, the user will be able to search for companies by category, get information and see the scene from different levels of detail.
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    Evaluating Three Versions of an Augmented Reality Mobile Game about Recycling
    (The Eurographics Association, 2012) Furió, D.; Juan, M.-Carmen; Alem, L.; Ashworth, P.; Isabel Navazo and Gustavo Patow
    We present three versions of an Augmented Reality (AR) game (basic, collaborative and competitive) for changing people attitudes with regard to climate change. We present a study in which twenty-eight primary school students have participated. To explore the extent to which the three AR game versions affected different aspects, the children had to answer questionnaires. The results did not show significant differences between the three versions. However, having into account the means and children preference, the competitive version could have had more influence on the participants.
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    Management of 3D Geometry on Portable Devices
    (The Eurographics Association, 2012) Martínez, José Olmos; Romero, Francisco Ramos; Gonzalez, Carlos; Isabel Navazo and Gustavo Patow
    The mobile devices has evolutioned quickly in the recent years. The Games industry realized the great potential of these devices and made many developments whose requirements makes devices reach their hardware limits so there is a need to improve performance. One way is to study different forms for efficient 3D models visualizations.
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    Interactive Virtual Tours with Panoramic Video
    (The Eurographics Association, 2012) Pérez, J.; Tamayo, I.; Garcia, J.; Isabel Navazo and Gustavo Patow
    This paper presents the work being carried out in the context of 360IN project for the development of an interactive platform for panoramic video on the web. The purpose of this platform is to have an application where the user can perform interactive virtual tours and get extra information concerning points of interest that are in the course.
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    From the Patient to the Surgery - A Complete Computer Vision and Graphics Process
    (The Eurographics Association, 2012) Martinez, A.; Jimenez, J.; Isabel Navazo and Gustavo Patow
    Generating digital information ready to use on a surgery operation from a patient is a complex process. This process involves computer vision techniques, in order to extract digital information from medical images, and computer graphics techniques in order to generate proper models to interact with the digital information. In this approach a set of techniques covering both fields (computer vision and graphics) have been used to develop a complete process from the medical image to the surgery training.
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    Design of an Information System for Cultural Heritage
    (The Eurographics Association, 2012) Soler, Francisco; Torres, Juan Carlos; León, Alejandro J.; Luzon, M. Victoria; Isabel Navazo and Gustavo Patow
    Usually the information that must be managed by archaeologist for any cultural heritage artefact is very heterogeneous. Due to its spatial nature this information cannot be easily represented with conventional data management frameworks. The strong spatial dependence of data concerning the object of study makes it interesting to have a three-dimensional model of the artefact to associate the large amount of information available. This paper presents a 3D information system that has been designed to manage cultural heritage information. The system allows to associate information layer to the artefact surface, following a GIS like approach. The association of information to the surface of the object allows to find out spatial relationships between different elements, making it easier to understand this information to both specialists and general public. The paper describes the system structure and functionality.
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    A New Approach to Explore Integral Field Spectroscopy Data
    (The Eurographics Association, 2012) Romo, Celia; Torres, Juan Carlos; León, Alejandro J.; Pérez, E.; Isabel Navazo and Gustavo Patow
    Integral field spectroscopy (IFS) is a technique that is widely used in astronomy. It gives simultaneously the spectra of each spatial sampling element of a given field, generating a large amount of information that is also known as data cube. Visualizing and exploring these data cubes in a flexible and an intuitive way is a challenge. Although the information collected is three-dimensional (representing the I(x, y, l) function) and the scientific community generally recognizes the need to use 3D visualization tools, two dimensional tools are usually used to visualize the data cubes and very few 3D exploration techniques have been proposed specifically for astrophysics. This paper presents an interactive method to explore IFS data and two different GPU implementations of it.
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    Point Cloud Visualization from Large-range Scanner in Android Devices
    (The Eurographics Association, 2012) Pamos, Miguel Á.; Segura, Rafael; Isabel Navazo and Gustavo Patow
    In this work, we introduce a study of how to render a cloud of points extracted from a scanner based on LIDAR technology in an Android tablet
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    Interactive Generation of (Paleontological) Scientific Illustrations from 3D-models
    (The Eurographics Association, 2012) Schäfer, Sebastian; Knopp, Christoph; Krömker, Detlef; Isabel Navazo and Gustavo Patow
    Scientific illustrations play an important role in the paleontological domain and are complex illustrations that are manually drawn. The artist creates illustrations that feature common expressive painting techniques: outlines, both irregular and periodic stippling as well as an abstract shaded surface in the background. We present a semiautomatic tool to generate these illustrations from 3D-models in real-time. It is based on an extensible GPU-based pipeline to interactively render characteristic into image-layers that are combined in an image-editing fashion. The user can choose the techniques used to render each layer and manipulate its key aspects. Using 3D- and 2D-painting the artist can still interact with the result and adjust it to his or her liking.
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    Population Dynamics Visualization
    (The Eurographics Association, 2012) Lozano, Miguel; García-Fernández, Ignacio; Orduña, Juan Manuel; Isabel Navazo and Gustavo Patow
    In this work we present a graphic, interactive system to validate population dynamics models through hypothesis (simulation results) and radiocarbon samples selection and process. The goal of the graphical tool is to allow the combination of different hypotheses (on the wavefront speed) in a single scenario, so that a more preceise selection of radiocarbon samples reduces global error of the mathematical model.
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    3D Interaction with Smartphone-like Devices
    (The Eurographics Association, 2012) Rodríguez, A.; León, A.; Torres, J. C.; Isabel Navazo and Gustavo Patow
    3D applications require a series of 3D operations that are difficult to perform with the traditional interaction devices such as mouse and keyboard. In this paper we present a new 3D interaction system using smartphone-like devices