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  • Contribution to Structural Parameters Computation: Volume Models and Methods

     Cruz Matias, Irving Alberto
    Defense's date: 2014-01-13
    Universitat Politècnica de Catalunya
    Theses

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    El Bio-Diseño Asistido por Computadora (Bio-CAD), y la experimentación in-silico están teniendo un creciente interés en aplicaciones biomédicas, en donde se utilizan datos científicos provenientes de muestras reales para calcular parámetros estructurales que permiten evaluar propiedades físicas. Las tecnologías de adquisición de imagen no invasivas como la TC, mTC o IRM, y el crecimiento constante de las prestaciones de las computadoras, permiten la adquisición, procesamiento y visualización de datos científicos con creciente grado de complejidad.El cálculo de parámetros estructurales está basado en la existencia de dos fases (o espacios) en la muestra: la sólida, que puede corresponder al hueso o material, y la fase porosa o vacía, por tanto, tales muestras son representadas como volúmenes binarios. El modelo de representación más común para estos conjuntos de datos es el modelo de vóxeles, el cuál es una extensión natural a 3D de los mapas de bits 2D. En esta tesis se utilizan el modelo Extreme Verrtices Model (EVM) y un nuevo modelo propuesto, the Compact Union of Disjoint Boxes (CUDB), para representar los volúmenes binarios en una forma mucho más compacta. El modelo EVM almacena sólo un subconjunto ordenado de vértices de la frontera del objeto mientras que el modelo CUDB mantiene una lista compacta de cajas.En esta tesis se proponen métodos para calcular los siguientes parámetros estructurales: distribución del tamaño de los poros, conectividad, orientación, esfericidad y redondez. La distribución del tamaño de los poros ayuda a interpretar las características de las muestras porosas permitiendo a los usuarios observar los rangos de diámetro más comunes de los poros mediante picos en un gráfica. La conectividad es una propiedad topológica relacionada con el género del espacio sólido, mide el nivel de interconectividad entre los elementos, y es un indicador de las características biomecánicas del hueso o de otros materiales. La orientación de un objeto puede ser definida por medio de ángulos de rotación alrededor de un conjunto de ejes ortogonales. La esfericidad es una medida de que tan esférica es una partícula , mientras que la redondez es la medida de la nitidez de sus aristas y esquinas.En el estudio de estos parámetros se trabaja con muestras reales escaneadas a alta resolución que suelen generar conjuntos de datos enormes, los cuales requieren una gran cantidad de memoria y mucho tiempo de procesamiento para ser analizados. Por esta razón, se presenta un nuevo método para simplificar volúmenes binarios de una manera progresiva y sin pérdidas. Este método genera una secuencia de niveles de detalle de los objetos, en donde cada objeto es un volumen englobante de los objetos previos. Además de ser utilizado como apoyo en el cálculo de parámetros estructurales, este método puede ser de utilizado en otras tareas como transmisión progresiva, detección de colisiones y cálculo de volumen de interés.Como parte de una investigación multidisciplinaria, se han desarrollado dos aplicaciones prácticas para calcular parámetros estructurales de muestras reales. Un software para la detección automática de puntos de viscosidad característicos en muestras de rocas de basalto y vidrios, y una aplicación para calcular la esfericidad y redondez de formas complejas en un conjunto de datos de sílice.

  • Region-based illustrative visualization of multimodal datasets

     Abellán Moreno, Pascual; Tost Pardell, Daniela; Grau Carrión, Sergi; Puig Puig, Ana
    Computerized medical imaging and graphics
    Date of publication: 2013-06-01
    Journal article

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    We present a rendering system for multiple overlapping volumes. The system is aimed at providing flexibility to merge data in different ways in different regions. For each region, users select one modality to be rendered alone or a pair of modalities to be merged. In fusion, the relative weights of each modality are defined with a 2D transfer function depending on the voxel's pair of property values. When one of the modalities has been pre-classified, a graph representation of the dataset is shown, and users select regions from it. Alternatively, users can define the regions interactively by painting on the volume. In both cases, they are allowed to assign a different fusion and shading functions to each region. In this way, illustrative images of the dataset can be easily generated applying effects of cutting away, ghosting and modality enhancement.

    We present as novel method for the exploration of multiple overlapping volumes that provides flexibility to merge data in different ways in different regions. In each region, either one of the modalities is rendered alone or the fusion of two modalities is shown. In the regions where data is fused, the relative weights of each modality are defined with a 2D transfer function depending on the voxel’s pair of property values. The regions can be defined interactively by painting on the volume. Alternatively, when one of the modalities has been pre-classified, a graph representation of the dataset is constructed, and regions can be defined as sets of voxels fulfilling a specific combination of classification criteria. In both cases, a different fusion and shading function can be defined for each region. In this way, illustrative images of the dataset can be easily generated applying effects of cutting away, ghosting and modality enhancement.

  • The wise cursor: assisted selection in 3D serious games

     Moya Santos, Sergio; Grau Carrión, Sergi; Tost Pardell, Daniela
    The visual computer
    Date of publication: 2013-06
    Journal article

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    In recent years, the evolution of 3D graphics hardware and software has lead to a growing interest for serious games in three-dimensional virtual environments for learning, training, and rehabilitation. Many of these games are based on a first-person-shooter paradigm in which users navigate through the environment, select, and manipulate virtual objects. The target users of these applications are not necessarily usual gamers, and they often have difficulties in navigating and interacting in the 3D environment. This paper proposes the wise cursor, a new method for selection that improves the usability and accessibility of mouse-driven serious games in 3D environments. At each user click, the proposed method computes a list of objects candidates to be selected and their probability of being the desired one. Depending on the uncertainty of the probability distribution, either one object is selected or a mechanism to clarify the selection is proposed. In the former case, if the selected object is within the user avatar¿s scope, the action associated to it is realized, otherwise the application automatically navigates toward it. In this way, selection and navigation are eased. The empirical results of the usability tests show that this technique is fast, practical, and that it requires little user¿s skills. Thus, it can make serious games usable for a wider range of users who can concentrate on the training objectives without technological barriers.

    In recent years, the evolution of 3D graphics hardware and software has lead to a growing interest for serious games in three-dimensional virtual environments for learning, training, and rehabilitation. Many of these games are based on a first-person-shooter paradigm in which users navigate through the environment, select, and manipulate virtual objects. The target users of these applications are not necessarily usual gamers, and they often have difficulties in navigating and interacting in the 3D environment. This paper proposes the wise cursor, a new method for selection that improves the usability and accessibility of mouse-driven serious games in 3D environments. At each user click, the proposed method computes a list of objects candidates to be selected and their probability of being the desired one. Depending on the uncertainty of the probability distribution, either one object is selected or a mechanism to clarify the selection is proposed. In the former case, if the selected object is within the user avatar’s scope, the action associated to it is realized, otherwise the application automatically navigates toward it. In this way, selection and navigation are eased. The empirical results of the usability tests show that this technique is fast, practical, and that it requires little user’s skills. Thus, it can make serious games usable for a wider range of users who can concentrate on the training objectives without technological barriers.

  • Assisted navigation for 3D serious games training

     Moya Santos, Sergio; Grau Carrión, Sergi; Tost Pardell, Daniela
    Congreso Internacional de Interacción Persona-Ordenador
    Presentation's date: 2013-09-17
    Presentation of work at congresses

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    Serious games in 3D virtual environments are becoming a popular tool for professional training activities as well as for rehabilitation. Navigation in 3D is recognized as one of the activity which is more dificult to master in this environments. In particular, elder users, less familiar with 3D games often do not know how to walk through these environments. They get puzzled without having been able to address the real purpose of the game. In this paper, we propose diferent enhancement methods to make navigation in 3D easier, and we describe the design and implementation of an automatic navigation mode, usable when navigation is needed to reach objects in the 3D world but is not a goal of the game by itself. We compare the results of an evaluation test of these dierent methods. We conclude that, for non-usual gamers, automatic navigation is the faster and preferred mode, whereas gamers prefer to control navigation themselves. For non-automatic navigation, the performance is better when the cursor is xed in the view center point during locomotion. On the contrary, for still positions, a free cursor is preferable. Finally, restriction of the pitch angle in a solid angle that encompasses the objects related to the task is better than a free pitch angle rotation for still positions. During locomotion, fixing the pitch angle at the horizontal level enhances the navigation.

  • Interactive graphical design of 3D serious neurorehabilitation games

     Moya, Sergio; Tost Pardell, Daniela; Grau Carrión, Sergi
    Presence - Teleoperators and virtual environments
    Date of publication: 2012-12
    Journal article

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  • Jeux qu'on prend au sérieux- Pour l'intercompréhension des langues étrangères

     Tost Planet, Manuel; Tost Pardell, Daniela
    Synergies
    Date of publication: 2012-12-13
    Journal article

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    The insertion of intercomprehension (IC) in a scholl context depends largely on the pedagogical materials brought to the ducational systems, which must be motivating and not too much disruptive to the institutions. In hat folllows, afetr briefly contextualizing this isue, we present the so-called "serious games" (SG) literature, mainly Anglo-saxon, applied to language learning, next we articulate SG with the parctice of IC before describing schematically an application, still under construction aimed at using SG for language learning from an IC perspective.

  • Personalization of virtual environments navigation and tasks for neurorehabilitation

     Tost Pardell, Daniela; Grau Carrión, Sergi; Moya Santos, Sergio
    Date of publication: 2012-04-02
    Book chapter

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  • Juegos serios para el entretenimiento de cirugía cardiaca

     Ayala Vallespi, M. Dolors; Pla Garcia, Nuria; Vigo Anglada, Marc; Solano Albajes, Luis; Eguia Gomez, Jose Luis; Grau Carrión, Sergi; Martinez Bayona, Jonas; Tost Pardell, Daniela
    Participation in a competitive project

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  • Jocs Seriosos per a la qualitat de vida i l'envelliment

     Tost Pardell, Daniela
    Jornada R+D+i en TIC i Salut a Catalunya
    Presentation's date: 2011-05-05
    Presentation of work at congresses

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  • Modeling, analysis and visualization of porous biomaterials

     Verges Garcia, Eduard
    Defense's date: 2011-07-11
    Department of Automatic Control, Universitat Politècnica de Catalunya
    Theses

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  • Visualización multimodal con texturas 3D

     Abellan Moreno, Pascual
    Defense's date: 2011-12-02
    Department of Automatic Control, Universitat Politècnica de Catalunya
    Theses

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  • 3D pore analysis of sedimentary rocks

     Verges Garcia, Eduard; Tost Pardell, Daniela; Ayala Vallespi, M. Dolors; Ramos, E.; Grau Carrión, Sergi
    Sedimentary geology
    Date of publication: 2011-03-01
    Journal article

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  • Animation of 3D Avatars for Rehabilitation of the Upper Limbs

     Moya, Sergio; Grau Carrión, Sergi; Tost Pardell, Daniela; Campeny, Ricard; Ruiz, Marcel
    Games and Virtual Worlds for Serious Applications (VS-GAMES), 2011 Third International Conference on
    Date of publication: 2011-07-29
    Journal article

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    The paper presents a 3D Virtual Environment (VE) for neurorehabilitation of the upper limb. Patients move one of their arms trying to simulate concrete daily actions, such as grasping a bottle, opening a door or putting a book on a shelve. They wear a special garment that integrates four inertial sensors providing in real time information on the orientation of the patient’s shoulder, elbow and wrist. The VE is a complete scenario integrating all the objects needed to perform virtually the actions simulated by the patients. In the VE, patients are represented by 3D avatars that, using the data provided by the inertial sensors, reproduce in real time their arm movements. Since only the arm movement is monitorized, but neither the hand nor the trunk and the neck, the system must combine real movements with baked animations in order to show a realistic behavior of the 3D avatar. Moreover, it must take into account collisions between the 3D avatar and the virtual objects. Finally, it must detect when the patient is about to simulate an interaction with an object in order to realize it virtually. We describe the strategies that we have designed to provide these functionalities.

  • Design of 3D Virtual Neuropsychological Rehabilitation Activities

     Grau Carrión, Sergi; Tost Pardell, Daniela; Campeny, Ricard; Moya, Sergio; Ruiz, Marcel
    International Conference on Games and Virtual Worlds for Serious Applications
    Presentation's date: 2010-03
    Presentation of work at congresses

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  • Exploration of porous structures with illustrative visualizations

     Grau Carrión, Sergi; Verges Garcia, Eduard; Tost Pardell, Daniela; Ayala Vallespi, M. Dolors
    Computers & graphics
    Date of publication: 2010
    Journal article

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  • INTERACTIVE FRAME RATES FOR GLOBALLY ILLUMINATED SCENES IN PRESENCE OF PARTICIPATING MEDIA

     JIMENEZ PEREZ, JUAN ROBERTO
    Defense's date: 2010-12-16
    Department of Software, Universitat Politècnica de Catalunya
    Theses

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  • Temporal run-length encoding: temporal coherence in rendering time-varying volume data

     Grau Carrión, Sergi; Tost Pardell, Daniela
    Date of publication: 2010-05-18
    Book

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  • PREVIRNEC: a cognitive telerehabilitation system based on Virtual Environments

     Tost Pardell, Daniela; Ferré, M; García, P; Tormos, J M; GARCÍA, A; Grau Carrión, Sergi
    VIRTUAL REHABILITATION INTERNATIONAL CONFERENCE
    Presentation of work at congresses

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  • TEMPORAL COHERENCE IN RENDERING TIME-VARYING VOLUME DATA.

     Grau Carrión, Sergi
    Defense's date: 2009-03-06
    Department of Software, Universitat Politècnica de Catalunya
    Theses

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  • Modelado, análisis y visualización de características de datos volumétricos en ingeniería biomédica

     Martinez Bayona, Jonas; Tost Pardell, Daniela; Pla Garcia, Nuria; Puig Puig, Ana; Vigo Anglada, Marc; Grau Carrión, Sergi; Verges Garcia, Eduard; Cruz Matias, Irving Alberto; Ferré Bergadà, Maria; Ayala Vallespi, M. Dolors
    Participation in a competitive project

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  • PREVIRNEC: a cognitive telerehabilitation system based on Virtual Environments

     Tost Pardell, Daniela
    VIRTUAL REHABILITATION INTERNATIONAL CONFERENCE
    Presentation's date: 2009-06-29
    Presentation of work at congresses

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  • Illustrative visualization of porous structures

     Grau Carrión, Sergi; Verges Garcia, Eduard; Tost Pardell, Daniela; Ayala Vallespi, M. Dolors
    SIMPOSIUM IBEROAMERICANO DE COMPUTACIÓN GRÁFICA
    Presentation's date: 2009
    Presentation of work at congresses

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  • Bio-CAD analysis of porosity bioimplants

     Verges Garcia, Eduard; Ayala Vallespi, M. Dolors; Grau Carrión, Sergi; Tost Pardell, Daniela
    European Symposium on Biomedical Engineering
    Presentation's date: 2008-06
    Presentation of work at congresses

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    In this work we present two methods to compute the porosity from a μCT image. One is the virtual simulation of a porosimeter and the other is a sphere-based heuristic approach. Both methods obtain a graph representing the pore space.

    Postprint (author’s final draft)

  • Frame-to-frame coherent GPU splatting

     Grau Carrión, Sergi; Tost Pardell, Daniela
    IADIS International conference on computer graphics and visualization
    Presentation's date: 2008-07
    Presentation of work at congresses

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  • Virtual Porosimeter

     Verges Garcia, Eduard; Ayala Vallespi, M. Dolors; Grau Carrión, Sergi; Tost Pardell, Daniela
    Computer-aided design and applications
    Date of publication: 2008
    Journal article

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    Recently, the term Bio-CAD has appeared to refer to the modeling of biological processes. This work focuses on the analysis of structural properties such as porosity of bioimplants for bone reconstruction. Specifically, we present a method that, using 3D microCT images, simulates the behavior of a porosimeter, i.e. an instrument to measure the porous structure of samples. After segmentation, we apply a process, based on connected component labeling and skeleton computation, which produces a result comparable to the real porosimeter experiment.

  • 3D reconstruction and quantification of porous structures

     Verges Garcia, Eduard; Ayala Vallespi, M. Dolors; Grau Carrión, Sergi; Tost Pardell, Daniela
    Computers & graphics
    Date of publication: 2008
    Journal article

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    In this paper, we describe the methodology that we have designed to quantify the pores distribution in bone implants and the empirical results that we have obtained with BioCAD designed scaffolds, microCT and confocal microscopy data. Our method is based on 3D digital topology properties of the porous structure. We segment the 3D images into three regions: exterior, bone and pore space. Next, we divide the pore space into pores and connection paths. We compute a graph of the pore space such that each node of the graph represents a pore, and an arc between two nodes indicates that the two pores are path-connected. On the basis of the graph and the segmented model, we are able to compute several properties of the material such as global porosity, effective porosity and radial pore distribution.

  • Accurate Interactive Specular Reflections and Refractions on Curved Objects

     ESTALELLA FERNÁNDEZ, PAU
    Defense's date: 2008-12-19
    Department of Software, Universitat Politècnica de Catalunya
    Theses

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  • Focus+context rendering of structured biomedical data

     Tost Pardell, Daniela
    Eurographics workshop on visual computing for biomedicine
    Presentation's date: 2008-10-06
    Presentation of work at congresses

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  • Time-varying multimodal volume rendering with 3d textures

     Abellán Moreno, Pascual; Grau Carrión, Sergi; Tost Pardell, Daniela
    International Conference on Computer Graphics Theory and Applications
    Presentation of work at congresses

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  • Focus+context rendering of structured biomedical data

     Abellán Moreno, Pascual; Puig, P; Tost Pardell, Daniela
    Eurographics workshop on visual computing for biomedicine
    Presentation of work at congresses

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  • Multimodal volume rendering with 3D textures

     Abellán Moreno, Pascual; Tost Pardell, Daniela
    Computers & graphics
    Date of publication: 2008-04-01
    Journal article

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  • 3d reconstruction and quantification of porous structures

     Vergès, E; Ayala Vallespi, M. Dolors; Grau Carrión, Sergi; Tost Pardell, Daniela
    II Congreso Español de Informática
    Presentation of work at congresses

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  • Image-space Sheet-Buffered Splatting on the GPU

     Grau Carrión, Sergi; Tost Pardell, Daniela
    IADIS Multi Conference on Computer Science and Information Systems 2007
    Presentation of work at congresses

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  • Multimodal volume rendering with 3d textures

     Abellán Moreno, Pascual; Tost Pardell, Daniela
    II Congreso Español de Informática
    Presentation of work at congresses

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  • Frame-to-frame coherent GPU ray-casting for time-varying volume data

     Grau Carrión, Sergi; Tost Pardell, Daniela
    Volume Modelling and Visualization 2007
    Presentation of work at congresses

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  • 3d reconstrucction of bone implants porous space

     Vergès, E; Ayala Vallespi, M. Dolors; Grau Carrión, Sergi; Tost Pardell, Daniela
    Congreso Anual de la Sociedad Española de Ingeniería Biomédica
    Presentation of work at congresses

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  • Image-space Sheet-Buffered Splatting on the GPU

     Grau Carrión, Sergi; Tost Pardell, Daniela
    Date: 2007-03
    Report

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  • Virtual Porosimeter

     Ayala Vallespi, M. Dolors; Grau Carrión, Sergi; Tost Pardell, Daniela
    Date: 2007-12
    Report

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  • Image-space shee-buffered splatting on the gpu

     Grau Carrión, Sergi; Tost Pardell, Daniela
    IADIs international journal on computer science and information systems
    Date of publication: 2007-10
    Journal article

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  • Image-space Sheet-Buffered Splatting on the GPU

     Grau Carrión, Sergi; Tost Pardell, Daniela
    IADIs international journal on computer science and information systems
    Date of publication: 2007-10
    Journal article

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  • Ray-casting time-varying volume data sets with frame-to-frame coherence

     Tost Pardell, Daniela; Grau Carrión, Sergi; Ferré, Maria; Puig Puig, Ana
    Visualization and Data Analysis
    Presentation's date: 2006
    Presentation of work at congresses

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  • Ray-Casting Time-varing volume datasets with frame-to-frame coherence

     Tost Pardell, Daniela; Grau, S; Ferré, M; Puig, A
    Visualization and Data Analysis 2006
    Presentation of work at congresses

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  • LEARNING METHODS APPLIED TO HIGH-RESOLUTION CT VOLUME DATA CLASSIFICATION

     Tost Pardell, Daniela
    9th International Conference in Computer Graphics and Artificial Intelligence
    Presentation's date: 2006-05-23
    Presentation of work at congresses

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  • Efficient focus+context visual exploration of volume datasets

     Campos, J; Puig, A; Tost Pardell, Daniela
    IBERO AMERICAN SYMPOSIUM IN COMPUTER GRAPHICS. XVI CONGRESO ESPAÑOL DE INFORMÁTICA GRÁFICA (CEIG)
    Presentation of work at congresses

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  • A gpu-driven algorithm for accurate interactive reflections on curved objects

     Estalella, P; Martín, I; Drettakis, G; Tost Pardell, Daniela
    17th Eurographics Symposium on Rendering
    Presentation of work at congresses

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  • Classification Algorithms for Biomedical Volume Datasets

     Tost Pardell, Daniela; Cerquides, J; López, M; Ontañón, S; Puertas, E; Puig, A; Pujol, O
    Date of publication: 2006-10-31
    Book chapter

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  • 3d reconstruction of bone implant poreous space

     Verges Garcia, Eduard; Ayala Vallespi, M. Dolors; Grau Carrión, Sergi; Tost Pardell, Daniela
    Congreso Anual de la Sociedad Española de Ingeniería Biomédica
    Presentation's date: 2006-11
    Presentation of work at congresses

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