Author: "Acquisition, representation and transformations for image synthesis (ARTIS)" - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Acquisition, representation and transformations for image synthesis (ARTIS)"' showing total 200 results

Start Over Author "Acquisition, representation and transformations for image synthesis (ARTIS)"

200 results on '"Acquisition, representation and transformations for image synthesis (ARTIS)"'

1. Meshless Finite Elements for Hierarchical Global Illumination

Author: Lehtinen, Jaakko, Zwicker, Matthias, Kontkanen, Janne, Turquin, Emmanuel, Sillion, François X., Aila, Timo, Computer Science and Artificial Intelligence Laboratory [Cambridge] ( CSAIL ), Massachusetts Institute of Technology ( MIT ), Department of Computer Science and Engineering [San Diego] ( CSE-UCSD ), University of California [San Diego] ( UC San Diego ), TKK Helsinki University of Technology, Helsinki University of Technology ( TKK ) -TKK, Acquisition, representation and transformations for image synthesis ( ARTIS ), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Laboratoire Jean Kuntzmann ( LJK ), Université Pierre Mendès France - Grenoble 2 ( UPMF ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Pierre Mendès France - Grenoble 2 ( UPMF ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Institut National Polytechnique de Grenoble ( INPG ), NVIDIA ( NVIDIA ), NVIDIA Corp., Publications in Telecommunications Software and Multimedia, Helsinki University of Technology, Computer Science and Artificial Intelligence Laboratory [Cambridge] (CSAIL), Massachusetts Institute of Technology (MIT), Department of Computer Science and Engineering [Univ California San Diego] (CSE - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), TKK Helsinki University of Technology (TKK), Acquisition, representation and transformations for image synthesis (ARTIS), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), NVIDIA (NVIDIA), Department of Computer Science and Engineering [San Diego] (CSE-UCSD), and University of California-University of California
Subjects: radiosity, global illumination, meshless finite elements, [ INFO.INFO-GR ] Computer Science [cs]/Graphics [cs.GR], [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], ComputingMethodologies_COMPUTERGRAPHICS, pre-computed radiance transfer
Abstract: We introduce a meshless finite element framework for solving light transport problems. Traditional finite element methods use basis functions parameterized directly on the mesh surface. The creation of suitable parameterizations or clusterings requires pre-processing that is difficult, error-prone, and sensitive to the quality of input geometry. The resulting light transport solutions still tend to exhibit discontinuities, necessitating heuristic post-processing before visualization. Due to these problems finite element methods are rarely used in production. The core idea of our approach is to use finite element basis functions induced by hierarchical scattered data approximation techniques. This leads to a mathematically rigorous recipe for meshless finite element illumination computations. As a main advantage, our approach decouples the function spaces used for solving the transport equations from the representation of the scene geometry. The resulting solutions are accurate, exhibit no spurious discontinuities, and can be visualized directly without post-processing, while parameterization, meshing and clustering problems are avoided. The resulting methods are furthermore easy to implement. We demonstrate the power of our framework by describing implementations of hierarchical radiosity, glossy precomputed radiance transfer from distant illumination, and diffuse indirect precomputed transport from local light sources. Moreover, we describe how to directly visualize the solutions on graphics hardware.
Published: 2007

2. Wavelet Radiance Transport for Interactive Indirect Lighting

Author: Kontkanen, Janne, Turquin, Emmanuel, Holzschuch, Nicolas, Sillion, François X., TKK Helsinki University of Technology (TKK), Acquisition, representation and transformations for image synthesis (ARTIS), Laboratoire d'informatique GRAphique, VIsion et Robotique de Grenoble (GRAVIR - IMAG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Inria Grenoble - Rhône-Alpes, Helsinki University of Technology ( TKK ), Acquisition, representation and transformations for image synthesis ( ARTIS ), Graphisme, Vision et Robotique ( GRAVIR - IMAG ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Inria Grenoble - Rhône-Alpes, and Institut National de Recherche en Informatique et en Automatique ( Inria ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, [ INFO.INFO-GR ] Computer Science [cs]/Graphics [cs.GR], ACM : I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], ComputingMethodologies_COMPUTERGRAPHICS
Abstract: International audience; Global illumination is a complex all-frequency phenomenon including subtle effects caused by indirect lighting. Computing global illumination interactively for dynamic lighting conditions has many potential applications, notably in architecture, motion pictures and computer games. It remains a challenging issue, despite the considerable amount of research work devoted to finding efficient methods. This paper presents a novel method for fast computation of indirect lighting; combined with a separate calculation of direct lighting, we provide interactive global illumination for scenes with diffuse and glossy materials, and arbitrarily distributed point light sources. To achieve this goal, we introduce three new tools: a 4D wavelet basis for concise radiance expression, an efficient hierarchical pre-computation of the Global Transport Operator representing the entire propagation of radiance in the scene in a single operation, and a run-time projection of direct lighting on to our wavelet basis. The resulting technique allows unprecedented freedom in the interactive manipulation of lighting for static scenes.
Published: 2006

3. Soft Shadow Volumes for Ray Tracing

Author: Samuli Laine, Timo Aila, Jaakko Lehtinen, Ulf Assarsson, Tomas Akenine-Möller, Helsinki University of Technology ( TKK ), Chalmers University of Technology [Göteborg], Acquisition, representation and transformations for image synthesis ( ARTIS ), Graphisme, Vision et Robotique ( GRAVIR - IMAG ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Centre National de la Recherche Scientifique ( CNRS ), Lund University [Lund], TKK Helsinki University of Technology (TKK), Acquisition, representation and transformations for image synthesis (ARTIS), Laboratoire d'informatique GRAphique, VIsion et Robotique de Grenoble (GRAVIR - IMAG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, and Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Computer science, Astrophysics::High Energy Astrophysical Phenomena, Shadow volume, 020207 software engineering, 02 engineering and technology, [ INFO.INFO-GR ] Computer Science [cs]/Graphics [cs.GR], Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Rendering (computer graphics), Silhouette, Shadow algorithms, Computer graphics (images), Shadow, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Ray tracing (graphics), Shadow mapping, Distributed ray tracing, visibility determination
Abstract: International audience; We present a new, fast algorithm for rendering physically-based soft shadows in ray tracing-based renderers. Our method replaces the hundreds of shadow rays commonly used in stochastic ray tracers with a single shadow ray and a local reconstruction of the visibility function. Compared to tracing the shadow rays, our algorithm produces exactly the same image while executing one to two orders of magnitude faster in the test scenes used. Our first contribution is a two-stage method for quickly determining the silhouette edges that overlap an area light source, as seen from the point to be shaded. Secondly, we show that these partial silhouettes of occluders, along with a single shadow ray, are sufficient for reconstructing the visibility function between the point and the light source.
Published: 2005

4. MNPR: A Framework for Real-Time Expressive Non-Photorealistic Rendering of 3D Computer Graphics

Author: Amir Semmo, Davide Benvenuti, Joëlle Thollot, Santiago E. Montesdeoca, Romain Vergne, Hock Soon Seah, Pierre Bénard, Nanyang Technological University [Singapour], Hasso Plattner Institute [Potsdam, Germany], Melting the frontiers between Light, Shape and Matter ( MANAO ), Laboratoire Bordelais de Recherche en Informatique ( LaBRI ), Centre National de la Recherche Scientifique ( CNRS ) -École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Université Sciences et Technologies - Bordeaux 1-Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique ( CNRS ) -École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Université Sciences et Technologies - Bordeaux 1-Université Bordeaux Segalen - Bordeaux 2-Inria Bordeaux - Sud-Ouest, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Laboratoire Photonique, Numérique et Nanosciences ( LP2N ), Université de Bordeaux ( UB ) -Institut d'Optique Graduate School ( IOGS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Bordeaux ( UB ) -Institut d'Optique Graduate School ( IOGS ) -Centre National de la Recherche Scientifique ( CNRS ), Models and Algorithms for Visualization and Rendering ( MAVERICK ), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Laboratoire Jean Kuntzmann ( LJK ), Université Pierre Mendès France - Grenoble 2 ( UPMF ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Pierre Mendès France - Grenoble 2 ( UPMF ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Institut National Polytechnique de Grenoble ( INPG ), Centre National de la Recherche Scientifique ( CNRS ) -Institut d'Optique Graduate School ( IOGS ) -Université de Bordeaux ( UB ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut d'Optique Graduate School ( IOGS ) -Université de Bordeaux ( UB ), Acquisition, representation and transformations for image synthesis ( ARTIS ), School of Computer Science and Engineering, School of Art, Design and Media, Interdisciplinary Graduate School (IGS), Expressive '18: Proceedings of the Joint Symposium on Computational Aesthetics and Sketch-Based Interfaces and Modeling and Non-Photorealistic Animation and Rendering, Melting the frontiers between Light, Shape and Matter (MANAO), Laboratoire Bordelais de Recherche en Informatique (LaBRI), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Inria Bordeaux - Sud-Ouest, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Photonique, Numérique et Nanosciences (LP2N), Université de Bordeaux (UB)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS), Models and Algorithms for Visualization and Rendering (MAVERICK ), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Laboratoire Jean Kuntzmann (LJK ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Université de Bordeaux (UB)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Centre National de la Recherche Scientifique (CNRS)-Inria Bordeaux - Sud-Ouest
Subjects: Interaction, Computer science, Object-space stylization, Framework, 020207 software engineering, 02 engineering and technology, [ INFO.INFO-GR ] Computer Science [cs]/Graphics [cs.GR], Levels of control, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Rendering (computer graphics), Non-photorealistic rendering, Object-space Stylization, Human–computer interaction, 0202 electrical engineering, electronic engineering, information engineering, Computer science and engineering [Engineering], 020201 artificial intelligence & image processing, Filtering, Expressive NPR, Real-time, 3D computer graphics, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: International audience; We propose a framework for expressive non-photorealistic rendering of 3D computer graphics: MNPR. Our work focuses on enabling stylization pipelines with a wide range of control, thereby covering the interaction spectrum with real-time feedback. In addition, we introduce control semantics that allow cross-stylistic art-direction, which is demonstrated through our implemented watercolor, oil and charcoal stylizations. Our generalized control semantics and their style-specific mappings are designed to be extrapolated to other styles, by adhering to the same control scheme. We then share our implementation details by breaking down our framework and elaborating on its inner workings. Finally, we evaluate the usefulness of each level of control through a user study involving 20 experienced artists and engineers in the industry, who have collectively spent over 245 hours using our system. MNPR is implemented in Autodesk ® Maya ® and open-sourced through this publication, to facilitate adoption by artists and further development by the expressive research and development community.
Published: 2018

5. A Compact Representation for Multiple Scattering in Participating Media using Neural Networks

Author: Nicolas Holzschuch, Beibei Wang, Liangsheng Ge, Lu Wang, Shandong University, Nanjing University of Science and Technology [Nanjing], Acquisition, representation and transformations for image synthesis ( ARTIS ), Graphisme, Vision et Robotique ( GRAVIR - IMAG ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Centre National de la Recherche Scientifique ( CNRS ), Nanjing University of Science and Technology (NJUST), Models and Algorithms for Visualization and Rendering (MAVERICK ), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Laboratoire Jean Kuntzmann (LJK ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Multiple Scattering, Artificial neural network, Neural Networks, Computer science, Scattering, Computation, 020207 software engineering, 02 engineering and technology, [ INFO.INFO-GR ] Computer Science [cs]/Graphics [cs.GR], Discrete dipole approximation, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Computational science, Participating Media, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Representation (mathematics), ComputingMethodologies_COMPUTERGRAPHICS
Abstract: International audience; Many materials, such as milk or wax, exhibit scattering effects; incoming light enters the material and is scattered inside, giving a translucent aspect. These effects are computationally intensive as they require simulating a large number of events. Full computations are expensive, even with accelerating methods such as Virtual Ray Lights. We present a method to encode multiple scattering effects using a neural network. We replace the precomputed multiple scattering table with a trained neural network, with a cost of 6490 bytes (1623 floats). At runtime, the neural network is used to generate multiple scattering. We demonstrate the effects combined with Virtual Ray Lights (VRL), but our approach can be integrated with other rendering algorithms.
Published: 2018

6. Edge-preserving multiscale image decomposition based on local extrema

Author: Kartic Subr, Frédo Durand, Cyril Soler, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Massachusetts Institute of Technology (MIT), ANR-07-BLAN-0331,HFIBMR,High-Fidelity Image-Based Modeling and Rendering(2007), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science, and Durand, Fredo
Subjects: Computer science, Property (programming), ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, ACM: I.: Computing Methodologies/I.4: IMAGE PROCESSING AND COMPUTER VISION/I.4.3: Enhancement/I.4.3.0: Filtering, 02 engineering and technology, computer.software_genre, Image (mathematics), Computational photography, Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, Computer vision, Mathematics, image decomposition, Multimedia, business.industry, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.5: Computational Geometry and Object Modeling/I.3.5.7: Physically based modeling, 020207 software engineering, Contrast (music), Computer Graphics and Computer-Aided Design, Computational photography (artistic), Maxima and minima, [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], Key (cryptography), computational photography, 020201 artificial intelligence & image processing, Artificial intelligence, Enhanced Data Rates for GSM Evolution, business, Maxima, computer, Algorithm
Abstract: We propose a new model for detail that inherently captures oscillations , a key property that distinguishes textures from individual edges. Inspired by techniques in empirical data analysis and morphological image analysis, we use the local extrema of the input image to extract information about oscillations: We define detail as oscillations between local minima and maxima. Building on the key observation that the spatial scale of oscillations are characterized by the density of local extrema, we develop an algorithm for decomposing images into multiple scales of superposed oscillations. Current edge-preserving image decompositions assume image detail to be low contrast variation. Consequently they apply filters that extract features with increasing contrast as successive layers of detail. As a result, they are unable to distinguish between high-contrast, fine-scale features and edges of similar contrast that are to be preserved. We compare our results with existing edge-preserving image decomposition algorithms and demonstrate exciting applications that are made possible by our new notion of detail.
Published: 2009

7. Frequency analysis and sheared reconstruction for rendering motion blur

Author: Frédo Durand, Kevin Egan, Yu-Ting Tseng, Nicolas Holzschuch, Ravi Ramamoorthi, Department of Computer Science [New York], Columbia University [New York], Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Massachusetts Institute of Technology (MIT), Computer Science and Artificial Intelligence Laboratory [Cambridge] (CSAIL), Department of Electrical Engineering and Computer Science [Berkeley] (EECS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), ANR-07-BLAN-0331,HFIBMR,High-Fidelity Image-Based Modeling and Rendering(2007), University of California [Berkeley], University of California-University of California, Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science, and Durand, Fredo
Subjects: Computer science, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 02 engineering and technology, Reconstruction filter, Anti-aliasing, law.invention, Rendering (computer graphics), ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, law, 0202 electrical engineering, electronic engineering, information engineering, 0601 history and archaeology, Computer vision, 14. Life underwater, Specular reflection, ComputingMethodologies_COMPUTERGRAPHICS, Frequency analysis, 060102 archaeology, Pixel, business.industry, Motion blur, 020207 software engineering, 06 humanities and the arts, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Computer Science::Graphics, Frequency domain, 020201 artificial intelligence & image processing, Artificial intelligence, business
Abstract: Motion blur is crucial for high-quality rendering, but is also very expensive. Our first contribution is a frequency analysis of motion-blurred scenes, including moving objects, specular reflections, and shadows. We show that motion induces a shear in the frequency domain, and that the spectrum of moving scenes can be approximated by a wedge. This allows us to compute adaptive space-time sampling rates, to accelerate rendering. For uniform velocities and standard axis-aligned reconstruction, we show that the product of spatial and temporal bandlimits or sampling rates is constant, independent of velocity. Our second contribution is a novel sheared reconstruction filter that is aligned to the first-order direction of motion and enables even lower sampling rates. We present a rendering algorithm that computes a sheared reconstruction filter per pixel, without any intermediate Fourier representation. This often permits synthesis of motion-blurred images with far fewer rendering samples than standard techniques require., United States. Office of Naval Research. Young Investigator Program (N00014-07-1-0900), United States. Office of Naval Research. (Grant number N00014-09-1-0741), National Science Foundation (U.S.). Graduate Research Fellowship Program, National Science Foundation (U.S.). (Grant number 0446916), National Science Foundation (U.S.). (Grant number 044756), National Science Foundation (U.S.). (Grant number 0701775), Alfred P. Sloan Foundation Fellowship, Microsoft Corporation. New Faculty Fellowship
Published: 2009

8. Texture Design and Draping in 2D Images

Author: Holger Winnemöller, Laurence Boissieux, A. Orzan, Joëlle Thollot, Adobe Systems Inc. (Adobe Advanced Technology Labs), Adobe Systems Inc., Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), SED [Grenoble], Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and Service Expérimentation et Développement (SED [Grenoble])
Subjects: 2d images, Computer science, business.industry, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 020207 software engineering, 02 engineering and technology, 3D modeling, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, business, Texture design
Abstract: International audience; We present a complete system for designing and manipulating regular or near-regular textures in 2D images. We place emphasis on supporting creative workflows that produce artwork from scratch. As such, our system provides tools to create, arrange, and manipulate textures in images with intuitive controls, and without requiring 3D modeling. Additionally, we ensure continued, non-destructive editability by expressing textures via a fully parametric descriptor. We demonstrate the suitability of our approach with numerous example images, created by an artist using our system, and we compare our proposed workflow with alternative 2D and 3D methods.
Published: 2009

9. Apparent Greyscale: A Simple and Fast Conversion to Perceptually Accurate Images and Video

Author: Pierre-Edouard Landes, Kaleigh Smith, Karol Myszkowski, Joëlle Thollot, Max-Planck-Institut für Informatik (MPII), Max-Planck-Gesellschaft, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: Lightness, business.industry, Computer science, media_common.quotation_subject, 020207 software engineering, 02 engineering and technology, Computer Graphics and Computer-Aided Design, Grayscale, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], law.invention, Image (mathematics), Chromatic contrast, Range (mathematics), Achromatic lens, law, Simple (abstract algebra), 0202 electrical engineering, electronic engineering, information engineering, Contrast (vision), 020201 artificial intelligence & image processing, Computer vision, Artificial intelligence, business, media_common
Abstract: International audience; The basic problem of greyscale transformation is to reproduce the intent of the colour original, its contrasts and salient features, while preserving the perceived magnitude and direction of its gradients. The transformation consists of two interdependent tasks: a mapping that assigns a grey value to each pixel or colour, and a discriminability constraint so that the achromatic differences match their corresponding original colour differences. Recent approaches solve discriminability constraints to determine the grey values, producing images in which the original colour contrasts are highly discriminable. However, the greyscale images may exhibit exaggerated dynamic range, an arbitrary achromatic order that differs among colour palettes, and a smoothing or masking of details. These modifications all contribute to make the grey version appear dissimilar from its original and create inconsistency among like images and video frames. The goal of this work is to create a perceptually accurate version of the colour image that represents its psychophysical effect on a viewer. Such greyscale imagery is important for printed textbooks and catalogues, the stylization of videos and for display on monochromatic medical displays. A perceptually accurate image is one that emulates both global and local impressions: it matches the original values' range and average luminance, its local contrasts are neither exaggerated nor understated, its grey values are ordered according to colour appearance and differences in spatial details are imperceptible. Strong perceptual similarity is particularly important for consistency over varying palettes and temporal coherence for animations.
Published: 2008

10. Clip Art Rendering of Smooth Isosurfaces

Author: Elmar Eisemann, Matei Stroila, John Hart, University of Illinois at Urbana-Champaign [Urbana], University of Illinois System, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), University of Illinois at Urbana Champaign (UIUC), and University of Illinois System-University of Illinois System
Subjects: Computer science, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Clip art, 02 engineering and technology, non-photorealistic rendering, 050105 experimental psychology, Pattern Recognition, Automated, Silhouette, Rendering (computer graphics), Computer graphics, User-Computer Interface, Vector graphics, Imaging, Three-Dimensional, Computer graphics (images), Image Interpretation, Computer-Assisted, Shadow, Computer Graphics, 0202 electrical engineering, electronic engineering, information engineering, 0501 psychology and cognitive sciences, Computer vision, particle systems, ComputingMethodologies_COMPUTERGRAPHICS, Particle system, business.industry, line art drawing, 05 social sciences, 020207 software engineering, Image Enhancement, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Non-photorealistic rendering, Signal Processing, Polygon, Computer Vision and Pattern Recognition, Artificial intelligence, business, Algorithms, Software
Abstract: International audience; Clip art is a simplified illustration form consisting of layered filled polygons or closed curves used to convey 3-D shape information in a 2-D vector graphics format. This paper focuses on the problem of direct conversion of smooth surfaces, ranging from the free-form shapes of art and design to the mathematical structures of geometry and topology, into a clip art form suitable for illustration use in books, papers and presentations. We show how to represent silhouette, shadow, gleam and other surface feature curves as the intersection of implicit surfaces, and derive equations for their efficient interrogation via particle chains. We further describe how to sort, orient, identify and fill the closed regions that overlay to form clip art. We demonstrate the results with numerous renderings used to illustrate the paper itself. More at http://artis.imag.fr/Publications/2008/SEH08/
Published: 2008

11. Stroke Pattern Analysis and Synthesis

Author: Simon Breslav, Pascal Barla, François X. Sillion, Joëlle Thollot, Lee Markosian, Acquisition, representation and transformations for image synthesis (ARTIS), Laboratoire d'informatique GRAphique, VIsion et Robotique de Grenoble (GRAVIR - IMAG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), Department of Electrical Engineering and Computer Science (EECS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Eduard Gröller and László Szirmay-Kalos, and Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Inria Grenoble - Rhône-Alpes
Subjects: ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism/I.3.7.1: Color, shading, shadowing, and texture, business.industry, Computer science, media_common.quotation_subject, Pattern analysis, 020207 software engineering, 02 engineering and technology, Extension (predicate logic), medicine.disease, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.4: Graphics Utilities/I.3.4.5: Paint systems, Perception, 0202 electrical engineering, electronic engineering, information engineering, medicine, 020201 artificial intelligence & image processing, Computer vision, Artificial intelligence, business, Stroke, media_common, Texture synthesis
Abstract: International audience; We present a synthesis technique that can automatically generate stroke patterns based on a user-speciﬁed reference pattern. Our method is an extension of texture synthesis techniques to vector-based patterns. Such an extension requires (a) an analysis of the pattern properties to extract meaningful pattern elements (deﬁned as clusters of strokes) and (b) a synthesis algorithm based on similarities in the detected stroke clusters. Our method is based on results from human vision research concerning perceptual organization. The resulting synthesized patterns effectively reproduce the properties of the input patterns, and can be used to ﬁll both 1D paths and 2D regions.
Published: 2006

12. Accurate detection of symmetries in 3D shapes

Author: François X. Sillion, Aurélien Martinet, Nicolas Holzschuch, Cyril Soler, Acquisition, representation and transformations for image synthesis (ARTIS), Laboratoire d'informatique GRAphique, VIsion et Robotique de Grenoble (GRAVIR - IMAG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), ANR Masses de Données 'SHOW', and Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Inria Grenoble - Rhône-Alpes
Subjects: Work (thermodynamics), Computation, Spherical harmonics, 020207 software engineering, 02 engineering and technology, Topology, 3d shapes, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Maxima and minima, Range (mathematics), Compression (functional analysis), Homogeneous space, 0202 electrical engineering, electronic engineering, information engineering, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.5: Computational Geometry and Object Modeling/I.3.5.2: Curve, surface, solid, and object representations, 020201 artificial intelligence & image processing, Algorithm, ComputingMethodologies_COMPUTERGRAPHICS, Mathematics
Abstract: We propose an automatic method for finding symmetries of 3D shapes, that is, isometric transforms which leave a shape globally unchanged. These symmetries are deterministically found through the use of an intermediate quantity: the generalized moments. By examining the extrema and spherical harmonic coefficients of these moments, we recover the parameters of the symmetries of the shape. The computation for large composite models is made efficient by using this information in an incremental algorithm capable of recovering the symmetries of a whole shape using the symmetries of its subparts. Applications of this work range from coherent remeshing of geometry with respect to the symmetries of a shape to geometric compression, intelligent mesh editing, and automatic instantiation.
Published: 2006

13. Real-Time Rendering of Rough Refraction

Author: Adrien Bousseau, Ravi Ramamoorthi, Kartic Subr, Charles de Rousiers, Nicolas Holzschuch, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Rendering and virtual environments with sound (REVES), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Computer science department [University College London] (UCL-CS), University College of London [London] (UCL), Models and Algorithms for Visualization and Rendering (MAVERICK), Department of Electrical Engineering and Computer Science [Berkeley] (EECS), University of California [Berkeley], University of California-University of California, ANR-07-MDCO-0001,ATROCO,Acquisition, Traitement et Rendu d'Objets Complexes(2007), Department of Computer science [University College of London] (UCL-CS), University of California [Berkeley] (UC Berkeley), and University of California (UC)-University of California (UC)
Subjects: Photon mapping, Scattering, business.industry, Computer science, 020207 software engineering, 02 engineering and technology, Computer Graphics and Computer-Aided Design, Real-time rendering, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Rendering (computer graphics), Optics, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, Signal Processing, 0202 electrical engineering, electronic engineering, information engineering, Surface roughness, Transmittance, 020201 artificial intelligence & image processing, Computer vision, Computer Vision and Pattern Recognition, Artificial intelligence, Cone tracing, business, Software, Distributed ray tracing
Abstract: International audience; We present an algorithm to render objects made of transparent materials with rough surfaces in real-time, under all-frequency distant illumination. Rough surfaces cause wide scattering as light enters and exits objects, which significantly complicates the rendering of such materials. We present two contributions to approximate the successive scattering events at interfaces, due to rough refraction: First, an approximation of the Bidirectional Transmittance Distribution Function (BTDF), using spherical Gaussians, suitable for real-time estimation of environment lighting using pre-convolution; second, a combination of cone tracing and macro-geometry filtering to efficiently integrate the scattered rays at the exiting interface of the object. We demonstrate the quality of our approximation by comparison against stochastic ray-tracing. Furthermore we propose two extensions to our method for supporting spatially varying roughness on object surfaces and local lighting for thin objects.
Published: 2012

14. Lissage multi-echelle sur GPU des images et volumes avec preservation des details

Author: Jibai, Nassim, Models and Algorithms for Visualization and Rendering (MAVERICK), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Université de Grenoble, Nicolas Holzschuch, and Acquisition, representation and transformations for image synthesis (ARTIS)
Subjects: Feature-preserving, Graphique Informatique, Multi-echelle, [MATH.MATH-GM]Mathematics [math]/General Mathematics [math.GM], Computer Graphics, GPU, Preservation des details, Lissage, Multi-scale, Smoothing
Abstract: Two-dimensional images and three-dimensional volumes have become a staple ingredient of our artistic, cultural, and scientific appetite. Images capture and immortalize an instance such as natural scenes, through a photograph camera. Moreover, they can capture details inside biological subjects through the use of CT (computer tomography) scans, X-Rays, ultrasound, etc. Three-dimensional volumes of objects are also of high interest in medical imaging, engineering, and analyzing cultural heritage. They are produced using tomographic reconstruction, a technique that combine a large series of 2D scans captured from multiple views. Typically, penetrative radiation is used to obtain each 2D scan: X-Rays for CT scans, radio-frequency waves for MRI (magnetic resonance imaging), electron-positron annihilation for PET scans, etc. Unfortunately, their acquisition is influenced by noise caused by different factors. Noise in two-dimensional images could be caused by low-light illumination, electronic defects, low-dose of radiation, and a mispositioning tool or object. Noise in three-dimensional volumes also come from a variety of sources: the limited number of views, lack of captor sensitivity, high contrasts, the reconstruction algorithms, etc. The constraint that data acquisition be noiseless is unrealistic. It is desirable to reduce, or eliminate, noise at the earliest stage in the application. However, removing noise while preserving the sharp features of an image or volume object remains a challenging task. We propose a multi-scale method to smooth 2D images and 3D tomographic data while preserving features at a specified scale. Our algorithm is controlled using a single user parameter – the minimum scale of features to be preserved. Any variation that is smaller than the specified scale is treated as noise and smoothed, while discontinuities such as corners, edges and detail at a larger scale are preserved. We demonstrate that our smoothed data produces clean images and clean contour surfaces of volumes using standard surface-extraction algorithms. In addition to, we compare our results with results of previous approaches. Our method is inspired by anisotropic diffusion. We compute our diffusion tensors from the local continuous histograms of gradients around each pixel in image; Les images et données volumiques sont devenues importantes dans notre vie quotidienne que ce soit sur le plan artistique, culturel, ou scientifique. Les données volumiques ont un intérêt important dans l'imagerie médicale, l'ingénierie, et l'analyse du patrimoine culturel. Ils sont créées en utilisant la reconstruction tomographique, une technique qui combine une large série de scans 2D capturés de plusieur points de vue. Chaque scan 2D est obtenu par des methodes de rayonnement : Rayons X pour les scanners CT, ondes radiofréquences pour les IRM, annihilation électron-positron pour les PET scans, etc. L'acquisition des images et données volumique est influencée par le bruit provoqué par différents facteurs. Le bruit dans les images peut être causée par un manque d'éclairage, des défauts électroniques, faible dose de rayonnement, et un mauvais positionnement de l'outil ou de l'objet. Le bruit dans les données volumique peut aussi provenir d'une variété de sources : le nombre limité de points de vue, le manque de sensibilité dans les capteurs, des contrastes élevé, les algorithmes de reconstruction employés, etc. L'acquisition de données non bruitée est iréalisable. Alors, il est souhaitable de réduire ou d'éliminer le bruit le plus tôt possible dans le pipeline. La suppression du bruit tout en préservant les caractéristiques fortes d'une image ou d'un objet volumique reste une tâche difficile. Nous proposons une méthode multi-échelle pour lisser des images 2D et des données tomographiques 3D tout en préservant les caractéristiques à l'échelle spécifiée. Notre algorithme est contrôlé par un seul paramètre – la taille des caractéristiques qui doivent être préservées. Toute variation qui est plus petite que l'échelle spécifiée est traitée comme bruit et lissée, tandis que les discontinuités telles que des coins, des bords et des détails à plus grande échelle sont conservés. Nous démontrons les données lissées produites par notre algorithme permettent d'obtenir des images nettes et des iso-surfaces plus propres. Nous comparons nos résultats avec ceux des methodes précédentes. Notre méthode est inspirée par la diffusion anisotrope. Nous calculons nos tenseurs de diffusion à partir des histogrammes continues locaux de gradients autour de chaque pixel dans les images et autour de chaque voxel dans des volumes. Comme notre méthode de lissage fonctionne entièrement sur GPU, il est extrêmement rapide.
Published: 2012

15. Visualisation interactive de grands volumes de données incertaines : pour une approche perceptive

Author: Coninx, Alexandre, Laboratoire de Physiologie de la Perception et de l'Action (LPPA), Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS), Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Models and Algorithms for Visualization and Rendering (MAVERICK), Simulation Neutronique, Technologies de l’Information et Calcul Scientifique (EDF R&D SINETICS), EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Université de Grenoble, Georges-Pierre Bonneau, and Jacques Droulez
Subjects: Scientific visualization, [MATH.MATH-GM]Mathematics [math]/General Mathematics [math.GM], Visual perception, Uncertainty, Visualisation scientifique, Perception visuelle, Simulation
Abstract: Current scientific and engineering works make an increasingly frequent use of numerical simulation techniques to study complex physical phenomenons. Visualizing these simulations' results on their geometric structure is often necessary in order to understand and analyze the simulated system. Such a visualization requires specific software tools in order to achieve a comprehensive and accurate depiction of the information present in the dataset. This includes taking into account the available information about dataset quality and data uncertainty. The goal of this thesis is to improve the visualization techniques for scalar data fields in order to integrate uncertainty information to the result. Our work follows a perceptual approach, using knowledge and experimental methods from visual perception research to put forward, study and implement new visualization techniques. A review of the state of the art on uncertainty visualization make us suggest to use an animated procedural noise as a visual primitive to show uncertainty. We set up a psychophysics experiment to evaluate contrast sensitivity thresholds for luminance stimuli generated using Perlin's noise algorithm, and therefore understand under which conditions such noise patterns can be perceived. These results are validated and extended by using a computational model of contrast sensitiviy, which we reimplemented and ran on our stimuli. The resulting information allow us to put forward a new technique for visualizing uncertain scalar data using an animated procedural noise and color maps. The resulting visualization is intuitive and efficient even for datasets with a complex tridimensional geometry. We apply this new technique to two industrial datasets, and demonstrate it to expert users. Their feedback uphold the usabiliy and efficiency of our technique, and allows us to add a few more improvements and to orient our future work.; Les études scientifiques et d'ingénierie actuelles font de plus en plus souvent appel à des techniques de simulation numérique pour étudier des phénomènes physiques complexes. La visualisation du résultat de ces simulations sur leur support spatial, souvent nécessaire à leur bonne compréhension, demande la mise en place d'outils adaptés, permettant une restitution fidèle et complète de l'information présente dans un jeu de données. Une telle visualisation doit donc prendre en compte les informations disponibles sur la qualité du jeu de données et l'incertitude présente. Cette thèse a pour but d'améliorer les méthodes de visualisation des champs de données scalaires de façon à intégrer une telle information d'incertitude. Les travaux présentés adoptent une approche perceptive, et utilisent les méthodes expérimentales et les connaissances préalables obtenues par la recherche sur la perception visuelle pour proposer, étudier et finalement mettre en oeuvre des nouvelles techniques de visualisation. Une revue de l'état de l'art sur la visualisation de données incertaines nous fait envisager l'utilisation d'un bruit procédural animé comme primitive pour la représentation de l'incertitude. Une expérience de psychophysique nous permet d'évaluer des seuils de sensibilité au contraste pour des stimuli de luminance générés par l'algorithme de bruit de Perlin, et de déterminer ainsi dans quelles conditions ces stimuli seront perçus. Ces résultats sont validés et étendus par l'utilisation d'un modèle computationnel de sensibilité au contraste, que nous avons réimplémenté et exécuté sur nos stimuli. Les informations obtenues nous permettent de proposer une technique de visualisation des données scalaires incertaines utilisant un bruit procédural animé et des échelles de couleur, intuitive et efficace même sur des géométries tridimensionnelles complexes. Cette technique est appliquée à deux jeux de données industriels, et présentée à des utilisateurs experts. Les commentaires de ces utilisateurs confirment l'efficacité et l'intérêt de notre technique et nous permettent de lui apporter quelques améliorations, ainsi que d'envisager des axes de recherche pour des travaux futurs.
Published: 2012

16. Screen space animation of fire

Author: Martin Guay, Fabrice Colin, Richard Egli, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), MOIVRE Centre, Université de Sherbrooke (UdeS), and SIGGRAPH
Subjects: 010101 applied mathematics, Computer science, Computer graphics (images), Scalar (mathematics), Screen space, Vector field, Animation, 0101 mathematics, Grid, 01 natural sciences, Compressible flow, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract: International audience; We present a simple and physically inspired method to animate realistically looking fire directly in 2D instead of along a 3D simulation. This naturally reduces the complexity of the animation from O(n3) to O(n2). The fire is represented as a 2D scalar density field located on a plane facing the camera, and is advected under a 2.5D velocity field. In our method, the apparent motion of the fire on the viewing axis is mimicked by introducing vibrations in the velocity field. We model these rapid vibrations as pressure waves found in compressible fluids and therefore consider the full Navier-Stokes equations. The equations can be solved in a single pass and our method entirely runs on the GPU. A natural extension is to make use of this method directly in screen space: instead of filtering down the fire's simulation grid in world space, we rasterize the fire's source, and perform the simulation on a coarser grid directly in screen space. The results are constantly renewed 3D-looking fires computed solely in 2D.
Published: 2011

17. Frequency based kernel estimation for progressive photon mapping

Author: Cyril Soler, Laurent Belcour, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), ACM SIGGRAPH, Zhigeng Pan, and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: Frequency analysis, Photon, Photon mapping, frequency analysis, Kernel density estimation, 020207 software engineering, 02 engineering and technology, Radius, Density estimation, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Computational physics, law.invention, law, Statistics, Convergence (routing), 0202 electrical engineering, electronic engineering, information engineering, Radiance, progressive photon mapping, Mathematics
Abstract: Poster; International audience; We present an extension to Hachisuka et al.'s Progressive Photon Mapping (or PPM) algorithm [Hachisuka et al. 2008] in which we estimate the radius of the density estimation kernels using frequency analysis of light transport [Durand et al. 2005]. We predict the local radiance frequency at the surface of objects using a Gaussian approximation, and use it to drive the size of the density estimation kernels, in order to accelerate convergence. The key is to add frequency information to a small proportion of photons: frequency photons. In addition to contributing to the density estimation, they will provide frequency information.
Published: 2011

18. A Visibility-Aware Model for Pre-Filtering and Rendering Surfaces in Real-Time

Author: Heitz, Eric, Neyret, Fabrice, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and INRIA
Subjects: [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract: We present a multiscale surface appearance representation and a rendering model that accounts for the subpixel visibility distribution. Starting from this model, we propose a method for pre-filtering detailed surfaces and their attributes. Our representation of the filtered attributes takes the correlation with their visibility into account. The masking and shadowing effects lost in geometric filtering of the surface can thus be recovered at rendering. This grants high visual quality of subpixel effects while ensuring a nearly constant per pixel computation complexity. Besides, accounting for subpixel occlusion naturally anti-aliases geometry. The computational model we propose has low memory and computational time requirements, and is thus well-suited for real-time rendering.; Nous proposons une représentation et un modèle de rendu prenant en compte la distribution de visibilité sous-pixel. En partant de ce modèle, nous proposons une méthode pour préfiltrer les surfaces détaillées et leurs attributs. Notre représentation filtrée des attributs surfaciques tient compte de leur corrélation avec leur visibilité et permet de reconstruire, au moment du rendu, les effets de masquage et d'ombrage perdus dans le filtrage géométrique de la surface. Ceci permet une grande qualité visuelle des effets sous-pixel avec un seul échantillon par pixel. En outre, la prise en compte des occlusions sous-pixel antialiase naturellement la géométrie. Le modèle de calcul et l'implémentation proposés sont légers en terme de stockage mémoire et en temps de calcul et satisfont les exigences d'un rendu temps-réel.
Published: 2011

19. State-of-the-Art Report on Temporal Coherence for Stylized Animations

Author: Joëlle Thollot, Pierre Bénard, Adrien Bousseau, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), Rendering and virtual environments with sound (REVES), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: Painting, Stylized fact, Multimedia, Computer science, media_common.quotation_subject, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 020207 software engineering, 02 engineering and technology, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.3: Picture/Image Generation, computer.software_genre, Computer Graphics and Computer-Aided Design, GeneralLiterature_MISCELLANEOUS, non-photorealistic rendering, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Rendering (computer graphics), Non-photorealistic rendering, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, Perception, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, stylization, computer, temporal coherence, media_common, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: International audience; Non-photorealistic rendering (NPR) algorithms allow the creation of images in a variety of styles, ranging from line drawing and pen-and-ink to oil painting and watercolor. These algorithms provide greater flexibility, control and automation over traditional drawing and painting. Despite significant progress over the past 15 years, the application of NPR to the generation of stylized animations remains an active area of research. The main challenge of computer generated stylized animations is to reproduce the look of traditional drawings and paintings while minimizing distracting flickering and sliding artifacts present in hand-drawn animations. These goals are inherently conflicting and any attempt to address the temporal coherence of stylized animations is a trade-off. This state-of-the-art report is motivated by the growing number of methods proposed in recent years and the need for a comprehensive analysis of the trade-offs they propose. We formalize the problem of temporal coherence in terms of goals and compare existing methods accordingly. We propose an analysis for both line and region stylization methods and discuss initial steps toward their perceptual evaluation. The goal of our report is to help uninformed readers to choose the method that best suits their needs, as well as motivate further research to address the limitations of existing methods.
Published: 2011

20. Interactive Indirect Illumination Using Voxel Cone Tracing

Author: Cyril Crassin, Miguel Sainz, Elmar Eisemann, Simon Green, Fabrice Neyret, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), NVIDIA (NVIDIA), and Télécom ParisTech
Subjects: Computer science, Global illumination, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, GPU, 02 engineering and technology, computer.software_genre, Octree, cone-tracing, Voxel, Computer graphics (images), final gather, 0202 electrical engineering, electronic engineering, information engineering, Computer vision, ComputingMethodologies_COMPUTERGRAPHICS, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism/I.3.7.1: Color, shading, shadowing, and texture, business.industry, Visibility (geometry), 020207 software engineering, real-time rendering, Computer Graphics and Computer-Aided Design, Real-time rendering, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Image synthesis, voxels, global illumination, Ambient occlusion, 020201 artificial intelligence & image processing, Artificial intelligence, Cone tracing, Bidirectional reflectance distribution function, business, computer, indirect lighting
Abstract: Special issue: Proceedings of Pacific Graphics - Session: Lighting & Rendering; International audience; Indirect illumination is an important element for realistic image synthesis, but its computation is expensive and highly dependent on the complexity of the scene and of the BRDF of the involved surfaces. While off-line computation and pre-baking can be acceptable for some cases, many applications (games, simulators, etc.) require real-time or interactive approaches to evaluate indirect illumination. We present a novel algorithm to compute indirect lighting in real-time that avoids costly precomputation steps and is not restricted to low-frequency illumination. It is based on a hierarchical voxel octree representation generated and updated on the fly from a regular scene mesh coupled with an approximate voxel cone tracing that allows for a fast estimation of the visibility and incoming energy. Our approach can manage two light bounces for both Lambertian and glossy materials at interactive framerates (25-70FPS). It exhibits an almost scene-independent performance and can handle complex scenes with dynamic content thanks to an interactive octree-voxelization scheme. In addition, we demonstrate that our voxel cone tracing can be used to efficiently estimate Ambient Occlusion.
Published: 2011

21. Visualization of uncertain scalar data fields using color scales and perceptually adapted noise

Author: Jacques Droulez, Alexandre Coninx, Guillaume Thibault, Georges-Pierre Bonneau, Laboratoire de Physiologie de la Perception et de l'Action (LPPA), Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS), Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), EDF (EDF), EDF R&D and a CIFRE grant from Association Nationale de la Recherche et de la Technologie, SIGGRAPH, and Stephen N. Spencer
Subjects: Computer science, Data field, 02 engineering and technology, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.3: Picture/Image Generation/I.3.3.3: Display algorithms, 050105 experimental psychology, Computer graphics, psychophysics, 0202 electrical engineering, electronic engineering, information engineering, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.8: Applications, 0501 psychology and cognitive sciences, Computer vision, Sensitivity (control systems), scientific visualization, ComputingMethodologies_COMPUTERGRAPHICS, contrast sensitivity, business.industry, 05 social sciences, Scientific visualization, Scalar (physics), 020207 software engineering, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Visualization, Noise, computer graphics, [SCCO.PSYC]Cognitive science/Psychology, uncertainty visualization, Artificial intelligence, Perlin noise, business
Abstract: Session: Visualization; International audience; We present a new method to visualize uncertain scalar data fields by combining color scale visualization techniques with animated, perceptually adapted Perlin noise. The parameters of the Perlin noise are controlled by the uncertainty information to produce animated patterns showing local data value and quality. In order to precisely control the perception of the noise patterns, we perform a psychophysical evaluation of contrast sensitivity thresholds for a set of Perlin noise stimuli. We validate and extend this evaluation using an existing computational model. This allows us to predict the perception of the uncertainty noise patterns for arbitrary choices of parameters. We demonstrate and discuss the efficiency and the benefits of our method with various settings, color maps and data sets.
Published: 2011

22. Multiscale Feature-Preserving Smoothing of Tomographic Data

Author: Nicolas Holzschuch, Kartic Subr, Nassim Jibai, Cyril Soler, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), Computer science department [University College London] (UCL-CS), University College of London [London] (UCL), ACM, Dan Wexler, Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and Department of Computer science [University College of London] (UCL-CS)
Subjects: Anisotropic diffusion, Computer science, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Feature-preserving smoothing, Edge-preserving smoothing, computer.software_genre, [INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG], 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Voxel, Histogram, Medical imaging, Computer vision, 030304 developmental biology, ComputingMethodologies_COMPUTERGRAPHICS, 0303 health sciences, Contouring, business.industry, anisotropic diffusion, Feature (computer vision), Tomography, Artificial intelligence, business, computer, Smoothing, Diffusion MRI
Abstract: Poster; International audience; Computer tomography (CT) has wide application in medical imaging and reverse engineering. Due to the limited number of projections used in reconstructing the volume, the resulting 3D data is typically noisy. Contouring such data, for surface extraction, yields surfaces with localised artifacts of complex topology. To avoid such artifacts, we propose a method for feature-preserving smoothing of CT data. The smoothing is based on anisotropic diffusion, with a diffusion tensor designed to smooth noise up to a given scale, while preserving features. We compute these diffusion kernels from the directional histograms of gradients around each voxel, using a fast GPU implementation.
Published: 2011

23. 3D Inverse Dynamic Modeling of Strands

Author: Florence Bertails-Descoubes, Alexandre Derouet-Jourdan, Joëlle Thollot, Modelling, Simulation, Control and Optimization of Non-Smooth Dynamical Systems (BIPOP), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Acquisition, representation and transformations for image synthesis (ARTIS), ACM SIGGRAPH, Dan Wexler, and Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)
Subjects: Flexibility (engineering), ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.0: General, business.industry, Computation, Process (computing), Motion (geometry), 020207 software engineering, 02 engineering and technology, Animation, 01 natural sciences, Pipeline (software), [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, GeneralLiterature_MISCELLANEOUS, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], 010305 fluids & plasmas, Range (mathematics), Geometric design, ACM: A.: General Literature/A.2: REFERENCE (e.g., dictionaries, encyclopedias, glossaries), Computer graphics (images), 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Computer vision, Artificial intelligence, business, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: 1D deformable structures, often called strands, are ubiquitous in the real world. They range from plants (grass, lianas, stalks) to creatures organs (hair, tail, tentacles) and manufactured objects (cables, ropes). The realistic modeling and animation of such objects is essential for representing convincing virtual environments. Most often, the design pipeline is split in two distinct parts: the geometry creation process itself, namely geometric design, followed by the computation of motion, namely animation. For the sake of flexibility and control, the geometric design generally relies on a pure geometric process that allows the user to interactively edit curve primitives such as splines. In contrast, the animation of strands is often considered as a passive and complex phenomenon that can be realistically captured using physics-based simulation.
Published: 2011

24. Link Conditions for Simplifying Meshes with Embedded Structures

Author: Dilip Mathew Thomas, Vijay Natarajan, Georges-Pierre Bonneau, Indian Institute of Science [Bangalore] (IISc Bangalore), Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), INRIA, Indian Institute of Science, and Grenoble University
Subjects: Quadric, Theoretical computer science, Computer science, 010102 general mathematics, 020207 software engineering, 02 engineering and technology, Topology, 01 natural sciences, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Domain (software engineering), Mesh generation, [MATH.MATH-AT]Mathematics [math]/Algebraic Topology [math.AT], Signal Processing, Metric (mathematics), 0202 electrical engineering, electronic engineering, information engineering, Edge contraction, Polygon mesh, Computer Vision and Pattern Recognition, Supercomputer Education & Research Centre, 0101 mathematics, Computer Science & Automation, Software, Topology (chemistry)
Abstract: International audience; Interactive visualization applications benefit from simplification techniques that generate good quality coarse meshes from high resolution meshes that represent the domain. These meshes often contain interesting substructures, called embedded structures, and it is desirable to preserve the topology of the embedded structures during simplification, in addition to preserving the topology of the domain. This paper describes a proof that link conditions, proposed earlier, are sufficient to ensure that edge contractions preserve topology of the embedded structures and the domain. Excluding two specific configurations, the link conditions are also shown to be necessary for topology preservation. Repeated application of edge contraction on an extended complex produces a coarser representation of the domain and the embedded structures. An extension of the quadric error metric is used to schedule edge contractions, resulting in a good quality coarse mesh that closely approximates the input domain and the embedded structures.
Published: 2011

25. La numérisation et la visualisation 3D de l'épitaphe de Costaulus

Author: Vergne, Romain, Mora, Pascal, Boutoulle, Frédéric, Frédéric Boutoulle and Dany Barraud and Jean-Luc Piat, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Archéo transfert, Centre National de la Recherche Scientifique (CNRS), Ausonius-Institut de recherche sur l'Antiquité et le Moyen âge, Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), LabEx Sciences archéologiques de Bordeaux (LASCARBX), Université de Bordeaux (UB)-Université Bordeaux Montaigne (UBM), Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Université Bordeaux Montaigne-Université de Bordeaux (UB), and Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)
Subjects: ComputingMilieux_MISCELLANEOUS, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract: National audience
Published: 2011

26. Feature-Based Vector Simulation of Water Waves

Author: Qizhi Yu, Anthony Steed, Fabrice Neyret, Virtual environments for animation and image synthesis of natural objects (EVASION), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Acquisition, representation and transformations for image synthesis (ARTIS), Department of Computer Science, and University College of London [London] (UCL)
Subjects: Surface (mathematics), real-time simulation, Computer science, water waves, 020207 software engineering, 02 engineering and technology, Animation, 01 natural sciences, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], 010305 fluids & plasmas, Controllability, Real-time simulation, Computer graphics (images), 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, procedural methods, Vector field, Polygon mesh, Graphics, Representation (mathematics), Software, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: We present a method for simulating local water waves caused by obstacles in water streams for real-time graphics applications. Given a low-resolution water surface and velocity field, our method is able to decorate the input water surface with high resolution detail for the animated waves around obstacles. We construct and animate a vector representation of the waves. It is then converted to feature-aligned meshes for capturing the surfaces of the waves. Results demonstrate that our method has the benefits of real-time performance and easy controllability. The method also fits well into a state-of-the-art river animation system. Copyright © 2011 John Wiley & Sons, Ltd.
Published: 2011

27. Interactive indirect illumination using voxel cone tracing

Author: Fabrice Neyret, Miguel Sainz, Elmar Eisemann, Cyril Crassin, Simon Green, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), NVIDIA (NVIDIA), and Télécom ParisTech
Subjects: Global illumination, Computer science, Computation, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 02 engineering and technology, computer.software_genre, GeneralLiterature_MISCELLANEOUS, Voxel, Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, Computer vision, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Shader, ComputingMilieux_MISCELLANEOUS, ComputingMethodologies_COMPUTERGRAPHICS, Pixel, business.industry, Visibility (geometry), 020207 software engineering, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], 020201 artificial intelligence & image processing, ComputingMethodologies_GENERAL, Artificial intelligence, Cone tracing, Bidirectional reflectance distribution function, business, computer
Abstract: Indirect illumination is an important element for realistic image synthesis, but its computation is expensive and highly dependent on the complexity of the scene and of the BRDF of the surfaces involved. While off-line computation and pre-baking can be acceptable for some cases, many applications (games, simulators, etc.) require real-time or interactive approaches to evaluate indirect illumination. In this paper, we present a novel real-time solution that calculates two light bounces - either glossy or diffuse - using a hierarchical voxel representation generated from a regular scene mesh. Our algorithm consists of two steps. First, direct illumination information (energy and direction) is emitted from dynamic area light sources and splatted into the voxel hierarchy, accounting for possible occluders. Secondly, we draw the scene mesh and compute the illumination in the pixel shader by combining the direct illumination and the indirect illumination received from the rest of the scene. For the latter, our approach employs an approximate voxel cone tracing to efficiently collect visibility and light in the hierarchical voxel representation of the scene. Our solution offers real-time and almost geometry-independent performance with a high visual quality for complex scenes with diffuse, as well as glossy surfaces.
Published: 2011

28. Interactive Indirect Illumination Using Voxel Cone Tracing: An Insight

Author: Crassin, Cyril, Neyret, Fabrice, Sainz, Miguel, Green, Simon, Eisemann, Elmar, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), NVIDIA (NVIDIA), and Télécom ParisTech
Subjects: ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], ComputingMethodologies_COMPUTERGRAPHICS
Abstract: International audience; (Siggraph 2011 Talk) Indirect illumination is an important element for realistic image synthesis, but its computation is expensive and highly dependent on the complexity of the scene and of the BRDF of the surfaces involved. While off-line computation and pre-baking can be acceptable for some cases, many applications (games, simulators, etc.) require real-time or interactive approaches to evaluate indirect illumination. We present a novel algorithm to compute indirect lighting in real-time that avoids costly precomputation steps and is not restricted to low frequency illumination. It is based on a hierarchical voxel octree representation generated and updated on-the-fly from a regular scene mesh coupled with an approximate voxel cone tracing that allows a fast estimation of the visibility and incoming energy. Our approach can manage two light bounces for both Lambertian and Glossy materials at interactive framerates (25-70FPS). It exhibits an almost scene-independent performance and allows for fully dynamic content thanks to an interactive octree voxelization scheme. In addition, we demonstrate that our voxel cone tracing can be used to efficiently estimate Ambient Occlusion.
Published: 2011

29. Lagrangian Texture Advection: Preserving both Spectrum and Velocity Field

Author: Nicolas Holzschuch, Fabrice Neyret, Eric Bruneton, Qizhi Yu, Virtual environments for animation and image synthesis of natural objects (EVASION), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Acquisition, representation and transformations for image synthesis (ARTIS), Marie Curie PhD grant through the VISITOR project (first author)., and ANR-07-MDCO-0001,ATROCO,Acquisition, Traitement et Rendu d'Objets Complexes(2007)
Subjects: Computer science, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 02 engineering and technology, Computer graphics, Physics::Fluid Dynamics, Image texture, Texture filtering, 0202 electrical engineering, electronic engineering, information engineering, Computer Graphics, Computer vision, Texture advection, Statistical physics, Texture, ComputingMethodologies_COMPUTERGRAPHICS, Pixel, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism/I.3.7.1: Color, shading, shadowing, and texture, business.industry, Texture (cosmology), Lagrangian methods, 020207 software engineering, Animation, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Visualization, Noise, Computer Science::Graphics, Particles, Computer Science::Computer Vision and Pattern Recognition, Signal Processing, 020201 artificial intelligence & image processing, Vector field, Computer Vision and Pattern Recognition, Artificial intelligence, business, Software
Abstract: International audience; Texturing an animated fluid is a useful way to augment the visual complexity of pictures without increasing the simulation time. But texturing flowing fluids is a complex issue, as it creates conflicting requirements: we want to keep the key texture properties (features, spectrum) while advecting the texture with the underlying flow - which distorts it. In this paper, we present a new, Lagrangian, method for advecting textures: the advected texture is computed only locally and follows the velocity field at each pixel. The texture retains its local properties, including its Fourier spectrum, even though it is accurately advected. Due to its Lagrangian nature, our algorithm can perform on very large, potentially infinite scenes in real time. Our experiments show that it is well suited for a wide range of input textures, including, but not limited to, noise textures.
Published: 2010

30. Stable Inverse Dynamic Curves

Author: Derouet-JourdanAlexandre, Bertails-DescoubesFlorence, ThollotJoëlle, Modelling, Simulation, Control and Optimization of Non-Smooth Dynamical Systems (BIPOP), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), Acquisition, representation and transformations for image synthesis (ARTIS), Grant from the Ecole Normale Superieure of Lyon (A. Derouet-Jourdan), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: Computer science, Stable equilibrium, Inverse, 020207 software engineering, Animation, 02 engineering and technology, 2d curve, elastica, Computer Graphics and Computer-Aided Design, Popularity, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Domain (software engineering), inverse statics, Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, stable equilibrium, ComputingMethodologies_COMPUTERGRAPHICS, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism/I.3.7.0: Animation
Abstract: Proceedings of SIGGRAPH Asia 2010 - Technical Papers: Curves, Characters & Crowds (Article 137); International audience; 2d animation is a traditional but fascinating domain that has recently regained popularity both in animated movies and video games. This paper introduces a method for automatically converting a smooth sketched curve into a 2d dynamic curve at stable equilibrium under gravity. The curve can then be physically animated to produce secondary motions in 2d animations or simple video games. Our approach proceeds in two steps. We first present a new technique to fit a smooth piecewise circular arcs curve to a sketched curve. Then we show how to compute the physical parameters of a dynamic rod model (super-circle) so that its stable rest shape under gravity exactly matches the fitted circular arcs curve. We demonstrate the interactivity and controllability of our approach on various examples where a user can intuitively setup efficient and precise 2d animations by specifying the input geometry.
Published: 2010

31. Contours actifs pour la stylisation cohérente de lignes animées

Author: Bénard, Pierre, Jingwan, Lu, Cole, Forrester, Finkelstein, Adam, Thollot, Joëlle, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), Department of Computer Science, Princeton University, Computer Science and Artificial Intelligence Laboratory [Cambridge] (CSAIL), Massachusetts Institute of Technology (MIT), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: contours actifs, rendu non-photoréaliste, dessin au trait, informatique graphique, cohérence temporelle, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract: Session Rendu 2 - 1er prix des meilleurs papiers; National audience; Cet article présente une méthode originale pour assurer la cohérence de la stylisation d'un dessin au trait extrait d'une scène 3D animée. Nous prenons en entrée des lignes dépendantes (silhouettes, contours suggestifs) ou non (crêtes, vallées) du point de vue. Ces lignes sont approximées et suivies par des polylignes 2D tout au long de l'animation de telle sorte que leur paramétrisation reflète le mouvement des lignes représentées tout en restant uniforme par morceau. Cette paramétrisation peut alors être utilisée comme support pour une stylisation au travers d'une pyramide de texture. Notre approche est interactive et permet d'assurer la continuité temporelle d'une large gamme de styles.
Published: 2010

32. Adaptive GPU Ray Casting Based on Spectral Analysis

Author: Rüdiger Dillmann, Stefan Suwelack, Roland Unterhinninghofen, Eric Heitz, Karlsruhe Institute of Technology (KIT), Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Klaus Tschira Foundation, Hongen Liao, P. J. 'Eddie' Edwards, Xiaochuan Pan, Yong Fan, and Guang-Zhong Yang
Subjects: Adaptive sampling, Speedup, business.industry, Computer science, 020207 software engineering, Volume rendering, 02 engineering and technology, Spectral analysis, Transfer function, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], 030218 nuclear medicine & medical imaging, Matrix decomposition, Visualization, Rendering (computer graphics), Gpu raycasting, 03 medical and health sciences, 0302 clinical medicine, Ray casting, 0202 electrical engineering, electronic engineering, information engineering, Computer vision, Artificial intelligence, business, Algorithm
Abstract: Oral session: Shape Modeling and Morphometry; International audience; GPU based ray casting has become a valuable tool for the visualization of medical image data. While the method produces high- quality images, its main drawback is the high computational load. We present a novel adaptive approach to speed up the rendering. In contrast to well established heuristic methods, we use the spectral decomposition of the transfer function and the dataset to derive a suitable sampling criterion. It is shown how this criterion can be e ciently incorporated into an adaptive ray casting algorithm. Two medical datasets, which each represent a typical, but di erent material distribution, are rendered using the proposed method. An analysis of the number of sample points per ray reveals that the new algorithm requires 50% to 80% less points compared to a non-adaptive method without any quality loss. We also show that the rendering speed of the GPU implementation is greatly increased with reference to the non-adaptive algorithm.
Published: 2010

33. A Deferred Shading Pipeline for Real-Time Indirect Illumination

Author: Olivier Hoel, Frank Rochet, Cyril Soler, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), EDEN Games, GARDEN (FUI), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: Deferred shading, business.industry, Computer science, Global illumination, Pipeline (computing), ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 020207 software engineering, Context (language use), 02 engineering and technology, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Constant (computer programming), Image-based lighting, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Computer vision, Artificial intelligence, business, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: CD Rom - Talk session: Split Second Screen Space; International audience; We present a deferred shading algorithm for computing screen-space multi-bounce indirect illumination with visibility, in real time. For each frame, we compute mipmapped G-Buffers of depth, normals, illumination and voxelized geometry. To each mipmap level we apply a single shader that gathers screen-space illumination using local Monte-Carlo integration. We upsample the illumination for all levels and smoothly combine them together. Our calculation is approximate but does not show artifacts, because it relies on noise-free Monte-Carlo integration of incoming illumination and temporal filtering. Our method simulates arbitrary distant illumination including visibility at a very low cost, because we only perform local texture lookups during computation. Besides, its deferred shading nature makes it independent of geometric and lighting complexity.
Published: 2010

34. NPR Gabor Noise for Coherent Stylization

Author: Pierre Bénard, Ares Lagae, Sylvain Lefebvre, Joëlle Thollot, George Drettakis, Peter Vangorp, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Rendering and virtual environments with sound (REVES), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Department of Computer Science [Leuven] (CS), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Geometry and Lighting (ALICE), INRIA Lorraine, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA), Institut National de Recherche en Informatique et en Automatique (Inria)-Université Henri Poincaré - Nancy 1 (UHP)-Université Nancy 2-Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS)-Université Henri Poincaré - Nancy 1 (UHP)-Université Nancy 2-Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)
Subjects: noise, business.industry, Computer science, expressive rendering, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 020207 software engineering, 02 engineering and technology, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.3: Picture/Image Generation, 3D rendering, non-photorealistic rendering, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Non-photorealistic rendering, Rendering (computer graphics), user study, Motion field, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Computer vision, Artificial intelligence, business, temporal coherence, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: Talk session: Fun In Flatland; International audience; We present a new solution for temporal coherence in non-photorealistic rendering (NPR) of animations. Given the conflicting goals of preserving the 2D aspect of the style and the 3D scene motion, any such solution is a trade-off. We observe that primitive-based methods in NPR can be seen as texture-based methods when using large numbers of primitives, leading to our key insight, namely that this process is similar to sparse convolution noise in procedural texturing. Consequently, we present a new primitive for NPR based on Gabor noise, that preserves the 2D aspect of noise, conveys the 3D motion of the scene, and is temporally continuous. We can thus use standard techniques from procedural texturing to create various styles, which we show for interactive NPR applications. We also present a user study to evaluate this and existing solutions, and to provide more insight in the trade-off implied by temporal coherence. The results of the study indicate that maintaining coherent motion is important, but also that our new solution provides a good compromise between the 2D aspect of the style and 3D motion.
Published: 2010

35. Efficient Rendering of Highly Detailed Volumetric Scenes with GigaVoxels

Author: Crassin, Cyril, Neyret, Fabrice, Sainz, Miguel, Eisemann, Elmar, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), NVIDIA (NVIDIA), Télécom ParisTech, and Wolfgang Engel
Subjects: Voxel, gpu, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, rendering, filtering, Real-Time, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], ComputingMethodologies_COMPUTERGRAPHICS, out-of-core
Abstract: International audience; GigaVoxels is a voxel-based rendering pipeline that makes the display of very large volumetric datasets very efficient. It is adapted to memory bound environments and it is designed for the data-parallel architecture of the GPU. It is capable of rendering objects at a detail level that matches the screen resolution and interactively adapts to the current point of view. Invisible parts are never even considered for contribution to the final image. As a result, the algorithm obtains interactive to real-time framerates and demonstrates the use of extreme amounts of voxels in rendering, which is applicable in many different contexts. This is also confirmed by many game developers who seriously consider voxels as a potential standard primitive in video games. We will also show in this chapter that voxels are already powerful primitives that, for some rendering tasks, achieve higher performance than triangle-based representations.
Published: 2010

36. Animating ultra-complex voxel scenes through shell deformation

Author: Rios Pavia, Daniel, Crassin, Cyril, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier (UJG - Grenoble I), and Cyril Crassin
Subjects: ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, GeneralLiterature_MISCELLANEOUS, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], ComputingMethodologies_COMPUTERGRAPHICS
Abstract: version draft du mémoire; International audience; Voxel representations have many advantages, such as ordered traversal during rendering and trivial very decent LOD through MIPmap. Special effect companies such Digital Domain or Rhythm&Hues now ex- tensively use voxels engines, for semi-transparent objects such as clouds, avalanches, tornado or explosions, but also for complex solid objects. Several gaming companies are also looking into voxel engines to deal with ever more complex scenes but the main problem when dealing with voxel representations is the amount of data that has to be manipulated. This amount usually prevents animating in real time. To solve these is- sues, ARTIS team developed the Gigavoxels framework: a very powerful voxel engine based on GPU ray-casting, with advanced memory man- agement, so that very complex scenes can be rendered in real-time. The purpose of the TER was to develop a solution for animating voxel objects in real-time, implement it and eventually integrate it to the Gigavoxels framework.
Published: 2010

37. Diffusion Constraints for Vector Graphics

Author: Elmar Eisemann, Doug DeCarlo, Joëlle Thollot, Hedlena Bezerra, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), Télécom ParisTech, Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers), CAPES Brazil (H. Bezerra) - The Alexander von Humboldt Foundation and the National Science Foundation under grant CCF-0541185 (D. DeCarlo)., and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: Diffusion (acoustics), Expressive rendering, business.industry, Anisotropic diffusion, Computer science, Linear system, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 020207 software engineering, 02 engineering and technology, Poisson equation, [INFO.INFO-CL]Computer Science [cs]/Computation and Language [cs.CL], Image (mathematics), Set (abstract data type), Vector graphics, Software, Diffusion process, Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, business, Algorithm, Color diffusion
Abstract: Session: Research papers; International audience; The formulation of Diffusion Curves [Orzan et al. 2008] allows for the flexible creation of vector graphics images from a set of curves and colors: a diffusion process fills out the parts of the image that are away from curves. However, this model has limitations in certain situations and does not always seem to agree with how an artist wants to use the software. First, the diffusion itself cannot be controlled, only the colors. Further, the fact that color needs to be defined everywhere along the curve can lead to tedious and nonintuitive interactions. In this paper, we present a number of adaptations to diffusion curves that constrain how color is spread across the image. Specifically, we argue for the utility of controlling the speed and direction of the color diffusion, and the ability to have barriers that can be defined without the need to specify a particular color along these curves. We also describe how this can be implemented by solving a linear system, and demonstrate the effectiveness of our solution on a number of examples.
Published: 2010

38. Self-Similar Texture for Coherent Line Stylization

Author: Adam Finkelstein, Pierre Bénard, Aleksey Golovinskiy, Forrester Cole, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Computer Science and Artificial Intelligence Laboratory [Cambridge] (CSAIL), Massachusetts Institute of Technology (MIT), Department of Computer Science, Princeton University, and Work sponsored in part by Adobe, Google, and the ExploraDoc program of the region Rhone-Alpes
Subjects: Texture representation, business.industry, Computer science, Line drawings, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 020207 software engineering, 02 engineering and technology, Animation, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Rendering (computer graphics), Non-photorealistic rendering, line drawing, Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, artmap, 020201 artificial intelligence & image processing, Computer vision, Artificial intelligence, Zoom, business, temporal coherence, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: Oral Session: Lines and Strokes; International audience; Stylized line rendering for animation has traditionally traded-off between two undesirable artifacts: stroke texture sliding and stroke texture stretching. This paper proposes a new stroke texture representation, the self-similar line artmap (SLAM), which avoids both these artifacts. SLAM textures provide continuous, infinite zoom while maintaining approximately constant appearance in screen-space, and can be produced automatically from a single exemplar. SLAMs can be used as drop-in replacements for conventional stroke textures in 2D illustration and animation. Furthermore, SLAMs enable a new, simple approach to temporally coherent rendering of 3D paths that is suitable for interactive applications. We demonstrate results for 2D and 3D animations.
Published: 2010

39. A dynamic noise primitive for coherent stylization

Author: Ares Lagae, George Drettakis, Pierre Bénard, Joëlle Thollot, Sylvain Lefebvre, Peter Vangorp, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), Rendering and virtual environments with sound (REVES), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Department of Computer Science [Leuven] (CS), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Geometry and Lighting (ALICE), INRIA Lorraine, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA), Institut National de Recherche en Informatique et en Automatique (Inria)-Université Henri Poincaré - Nancy 1 (UHP)-Université Nancy 2-Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS)-Université Henri Poincaré - Nancy 1 (UHP)-Université Nancy 2-Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS), K.U.Leuven CREA funding (CREA/08/017), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: noise, Computer science, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 02 engineering and technology, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.3: Picture/Image Generation, non-photorealistic rendering, 050105 experimental psychology, Rendering (computer graphics), 0202 electrical engineering, electronic engineering, information engineering, 0501 psychology and cognitive sciences, Computer vision, Dynamic noise, temporal coherence, ComputingMethodologies_COMPUTERGRAPHICS, expressive rendering, business.industry, 05 social sciences, 020207 software engineering, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Non-photorealistic rendering, user study, Procedural texture, Artificial intelligence, business, Algorithm
Abstract: We present a new solution for temporal coherence in non-photorealistic rendering (NPR) of animations. Given the conflicting goals of preserving the 2D aspect of the style and the 3D scene motion, any such solution is a trade-off. We observe that primitive-based methods in NPR can be seen as texture-based methods when using large numbers of primitives, leading to our key insight, namely that this process is similar to sparse convolution noise in procedural texturing. Consequently, we present a new primitive for NPR based on Gabor noise, that preserves the 2D aspect of noise, conveys the 3D motion of the scene, and is temporally continuous. We can thus use standard techniques from procedural texturing to create various styles, which we show for interactive NPR applications. We also present a user study to evaluate this and existing solutions, and to provide more insight in the trade-off implied by temporal coherence. The results of the study indicate that maintaining coherent motion is important, but also that our new solution provides a good compromise between the 2D aspect of the style and 3D motion. ispartof: Computer Graphics Forum vol:29 issue:4 pages:1497-1506 ispartof: location:Saarbrücken, Germany status: published
Published: 2010

40. A physically-based particle model of emergent crowd behaviors

Author: Heigeas, Laure, Luciani, Annie, Thollot, Joëlle, Castagné, Nicolas, Acquisition, representation and transformations for image synthesis (ARTIS), Laboratoire d'informatique GRAphique, VIsion et Robotique de Grenoble (GRAVIR - IMAG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), ACROE - Ingénierie de la Création Artistique (ACROE-ICA), Ministère de la Culture et de la Communication (MCC)-Institut National Polytechnique de Grenoble (INPG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes
Subjects: FOS: Computer and information sciences, Computer Science - Graphics, physically-based particle model, FOS: Physical sciences, emergent behavior, Computational Physics (physics.comp-ph), Crowd simulation and rendering, image-based rendering, Physics - Computational Physics, Graphics (cs.GR), [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract: This paper presents a modeling process in order to produce a realistic simulation of crowds in the ancient Greek agora of Argos. This place was a social theater in which two kinds of collective phenomena took place: interpersonal interactions (small group discussion and negotiation, etc.) and global collective phenomena, such as flowing and jamming. In this paper, we focus on the second type of collective human phenomena, called non-deliberative emergent crowd phenomena. This is a typical case of collective emergent self-organization. When a great number of individuals move within a confined environment and under a common fate, collective structures appear spontaneously: jamming with inner collapses, organized flowing with queues, curls, and vortices, propagation effects, etc. These are particularly relevant features to enhance the realism - more precisely the "truthfulness" - of models of this kind of collective phenomena. We assume that this truthfulness is strongly associated with the concept of emergence: evolutions are not predetermined by the individual characters, but emerge from the interaction of numerous characters. The evolutions are not repetitive, and evolve on the basis of small changes. This paper demonstrates that the physically-based interacting particles system is an adequate candidate to model emergent crowd effects: it associates a large number of elementary dynamic actors via elementary non-linear dynamic interactions. Our model of the scene is regulated as a large, dynamically coupled network of second order differential automata. We take advantage of symbolic non-photorealistic and efficient visualization to render the style of the person, rather than the person itself. As an artistic representation, NPR reinforces the symbolic acceptance of the scene by the observer, triggering an immediate and intuitive recognition of the scene as a plausible scene from ancient Greece., Graphicon 2003, Moscou : Russian Federation (2003)
Published: 2010

41. Narrative rendering in computer graphics

Author: Stein, Thierry, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Université Joseph-Fourier - Grenoble I, Nicolas Holzschuch, François Sillion(Nicolas.Holzschuch@inrialpes.fr, Francois.Sillion@inrialpes.fr), and Stein, Thierry
Subjects: Visualisation, motion depiction, annotation, Viusalization, Rendu Non-photorealiste, annoation, description du mouvement, [INFO.INFO-HC]Computer Science [cs]/Human-Computer Interaction [cs.HC], [INFO.INFO-HC] Computer Science [cs]/Human-Computer Interaction [cs.HC], Non-photorealistic rendering
Abstract: Creating a sequence of images that illustrates an animation is a task that finds applications in many fields, from comics to assembly schemes. Such a representation is based on the projection of 3D plus time data to 2D and necessarily involves loss of information. Compensation for this loss is generally handmade and is currently performed on an individual case basis. The objective of this thesis is to develop algorithms to automate this task as generally as possible. In this context, we are interested in pictorial visualization of particle animations by identifying and illustrating their aggregate movement. For animations taking place in a specific geometrical context, we propose a method to display this context while taking into account the animation summary. Finally, to enhance our pictures with textual or contextual information, we studied the problem of dynamic labeling of 3D scenes and the associated problems of temporal discontinuities and incoherence., Créer une séquence d´images qui résume une animation est une tache effectuée dans de nombreux domaines, allant de la bande-dessinée à la conception de schémas d´assemblage. Une telle représentation repose sur la projection de données 3D plus temps vers un support 2D, et induit inévitablement une perte d´informations. Compenser cette perte relève encore aujourd´hui du traitement au cas par cas, et est très généralement fait de manière manuelle. L´objectif de cette thèse est de développer des algorithmes automatisant cette tache et restant les plus généraux possible. Dans ce contexte, nous nous sommes intéressés à la visualisation en images d´animations de particules, en essayant d´identifier puis d'illustrer leurs mouvements généraux. Une animation se déroulant généralement dans un décor géométrique spécifique, nous avons proposé une méthode pour afficher ce décor en tenant compte du résumé de l'animation. Enfin, afin d´enrichir nos images d´informations textuelles ou contextuelles, nous avons étudié le problème de l´annotation dynamique d´une scène 3D et les difficultés de cohérence temporelle soulevées.
Published: 2010

42. Real-time Rendering of Heterogeneous Translucent Objects with Arbitrary Shapes

Author: Jun-Hai Yong, Jiaping Wang, Nicolas Holzschuch, Yajun Wang, Kartic Subr, Baining Guo, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Tsinghua University [Beijing] (THU), Microsoft Research Asia, School of Software (THSS), National Science Foundation of China (60625202, 60911130368), Chinese 863 Program (2007AA040401), and INRIA internship grant, and ANR-07-BLAN-0331,HFIBMR,High-Fidelity Image-Based Modeling and Rendering(2007)
Subjects: Diffusion equation, Computer science, OpenGL, 020207 software engineering, 02 engineering and technology, Computer Graphics and Computer-Aided Design, Light scattering, Real-time rendering, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Rendering (computer graphics), Computer Science::Graphics, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: EUROGRAPHICS 2010 (full paper) - Session Rendering I; International audience; We present a real-time algorithm for rendering translucent objects of arbitrary shapes. We approximate the scattering of light inside the objects using the diffusion equation, which we solve on-the-fly using the GPU. Our algorithm is general enough to handle arbitrary geometry, heterogeneous materials, deformable objects and modifications of lighting, all in real-time. In a pre-processing step, we discretize the object into a regular 4-connected structure (quadgraph). Due to its regular connectivity, this structure is easily packed into a texture and stored on the GPU. At runtime, we use the quadgraph stored on the GPU to solve the diffusion equation, in real-time, taking into account the varying input conditions: incoming light, object material and geometry. We handle deformable objects, provided the deformation does not change the topological structure of the objects.
Published: 2010

43. Real-time Realistic Ocean Lighting using Seamless Transitions from Geometry to BRDF

Author: Fabrice Neyret, Nicolas Holzschuch, Eric Bruneton, Virtual environments for animation and image synthesis of natural objects (EVASION), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Acquisition, representation and transformations for image synthesis (ARTIS), and ANR-07-MDCO-0001,ATROCO,Acquisition, Traitement et Rendu d'Objets Complexes(2007)
Subjects: 010504 meteorology & atmospheric sciences, Computer science, media_common.quotation_subject, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Geometry, 02 engineering and technology, 01 natural sciences, Rendering (computer graphics), Computer graphics, ACM: I.: Computing Methodologies/I.3: COMPUTER GRAPHICS/I.3.7: Three-Dimensional Graphics and Realism, Computer graphics (images), 0202 electrical engineering, electronic engineering, information engineering, Computer vision, 0105 earth and related environmental sciences, media_common, ComputingMethodologies_COMPUTERGRAPHICS, business.industry, 020207 software engineering, Animation, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Sky, Bidirectional reflectance distribution function, Artificial intelligence, business, Level of detail
Abstract: EUROGRAPHICS 2010 (full paper) - Session Rendering I; International audience; Realistic animation and rendering of the ocean is an important aspect for simulators, movies and video games. By nature, the ocean is a difficult problem for Computer Graphics: it is a dynamic system, it combines wave trains at all scales, ranging from kilometric to millimetric. Worse, the ocean is usually viewed at several distances, from very close to the viewpoint to the horizon, increasing the multi-scale issue, and resulting in aliasing problems. The illumination comes from natural light sources (the Sun and the sky dome), is also dynamic, and often underlines the aliasing issues. In this paper, we present a new algorithm for modelling, animation, illumination and rendering of the ocean, in real-time, at all scales and for all viewing distances. Our algorithm is based on a hierarchical representation, combining geometry, normals and BRDF. For each viewing distance, we compute a simplified version of the geometry, and encode the missing details into the normal and the BRDF, depending on the level of detail required. We then use this hierarchical representation for illumination and rendering. Our algorithm runs in real-time, and produces highly realistic pictures and animations.
Published: 2010

44. Ce qu'il y a de bien (ou de mal) dans l'évaluation bibliométrique telle que pratiquée par l'AERES

Author: Holzschuch, Nicolas, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and Holzschuch, Nicolas
Subjects: [INFO.INFO-GR] Computer Science [cs]/Graphics [cs.GR], [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract: The French higher education and research evaluation body (AERES, Agence d'évaluation de la recherche et de l'enseignement supérieur) was set up to carry out evaluations in the French university system. One of the key criteria used by AERES experts is the number of publications per researcher. Nicolas Holzschuch has studied the pros and cons of this method of evaluation. Some aspects of the method have proved controversial, including the way articles are counted depending on the field of research and the creation of lists of journals by categories of prestige. However, implementing the evaluation process has made researchers focus more on publication, which has had a positive impact on research., L'Agence d'évaluation de la recherche et de l'enseignement supérieur (AERES) a pour mission l'évaluation du système universitaire français. Parmi les critères qui entrent en jeu, les experts comptabilisent les publications des chercheurs. L'article de Nicolas Holzschuch fait le bilan des effets pervers mais aussi des conséquences positives de cette forme d'évaluation. En effet, la façon dont sont comptabilisés les articles selon les disciplines ainsi que la création de listes de revues dites de bonne qualité peuvent prêter à polémique. A contrario, l'instauration de cette évaluation oblige les chercheurs à mettre davantage l'accent sur la publication... En cela, l'AERES a un effet positif sur la recherche.
Published: 2010

45. Controllable Diffusion Curves

Author: Bezerra, Hedlena, Eisemann, Elmar, Decarlo, Doug, Thollot, Joëlle, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Télécom ParisTech, Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers), INRIA, and Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)
Subjects: color diffusion, expressive rendering, Poisson equation, [INFO.INFO-CL]Computer Science [cs]/Computation and Language [cs.CL]
Abstract: Thème : Acquisition, Representation and Transformations for Image Synthesis; This report introduces new drawing tools for controlling color diffusion in an image. It builds on the Diffusion-Curve algorithm, which computes images by diffusing colors from user-defined constraint curves. However, control of the diffusion process was limited in significant ways. In this report, we adapt the representation of Diffusion Curves by allowing artists to specify color strength, diffusion directions, and non-diffusing barriers. We also describe the algorithmic changes necessary for their efficient implementation. We demonstrate how these extensions give artists more control, and streamline the editing process in common situations.; Dans cet rapport nous présentons plusieurs outils de contrôle de la diffusion de couleurs dans une image. Ces outils sont mis en œuvre sous forme d'extensions de l'approche "courbes de diffusions" qui consiste à calculer une image à partir de contraintes placées le long de courbes. Nous proposons ici d'étendre la représentation par courbes de diffusion pour permettre à un artiste de dé finir localement la puissance de la diffusion, sa direction ainsi que des courbes barrières qui peuvent stopper la diffusion. Nous décrivons de plus les modifications algorithmiques nécessaires pour une implémentation efficace.
Published: 2010

46. Computer-Aided Control for Expressive Rendering

Author: De Almeida Bezerra, Hedlena Maria, De Almeida Bezerra, Hedlena Maria, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Grenoble - INPG, and François Sillion(Francois.Sillion@inrialpes.fr)
Subjects: Rendu expressif, Stylization, Computer Graphics, Rendu nonphotoréaliste, Informatique graphique, Drawing tools, [INFO.INFO-HC]Computer Science [cs]/Human-Computer Interaction [cs.HC], [INFO.INFO-HC] Computer Science [cs]/Human-Computer Interaction [cs.HC], Expressive Rendering, Outils de dessin, Non-Photorealistic Rendering
Abstract: Digital edition, creation, and design bring the computer's extraordinary flexibility to the act of creation. The near absence of penalty for experimentation can be, however, both a blessing and a curse. Although the unprecedent flexibility of the computer encourages exploration of artistic ideas, it also can be a factor of great distraction to the artist. A great challenge for the development of graphics softwares today is, thus, to take advantage of computer's unprecedented flexibility, while offering to the user the adapted level of control that she or he is looking for. The difficulty when designing such adapted system is highly influenced by the expectations users place on the job performed by computers. As the computer places itself in the role of an assistant in the creation process, we expect it to be 'smart enough' to deserve this place. Usually, we do not accept well when the result of such assistance is not satisfactory. Nevertheless, the level of expectation, and consequently, satisfaction, is not the same for all users. Novice users tend to be less exigent and are often happy when the computer help them to create interesting results without the need of a strong user intervention. Professional users, on the other hand, usually have different needs. They are looking forward to softwares that are good enough in automatizing tasks, but also that provide intuitive controls to manipulate their results. For these users, the bigger is the impact of the work generated by the computer in the final result, the more these tasks are subjected to have control parameters. In this thesis, we demonstrate that the computer can be placed as an incomparable assistant into the visual creation process once well-adapted interaction systems are provided. Adaptation is thus an important aspect because, in different levels, users want to be able to have the control over the result in order to give their touch and express their creativity. The thesis presents two different scenarios demonstrating that controllability plays a major role in expressiveness: a real-time technique to cluster a dynamic 3D scene in order to achieve an automatic, yet controllable output that can then be used as input to any rendering style; and a number of adaptations to a drawing vector graphics primitive called Diffusion Curves that constrain and control the creation of complex color gradients. The thesis proposes, on one hand, mathematical and computational well-adapted representations to provide the user with different levels of control over algorithms of expressive rendering in order to manipulate two- and tridimensional scenes; and, on the other hand, to reproject this technical support into user-friendly software solutions., L'édition, la création, et le design digital mènent la flexibilité des ordinateurs vers l'acte de création. La quasi-absence de conséquences par l'expérimentation peut être à la fois une bonne et une mauvaise chose. Bien que la flexibilité des ordinateurs encourage l'exploration d'idées artistiques, elle peut également la freiner, en proposant trop d'options mal-adaptées. Un grand défi pour le développement des logiciels graphiques aujourd'hui est de tirer parti de la flexibilité sans précédent des ordinateurs, tout en offrant à l'utilisateur le niveau de contrôle adapté à ses besoins. La difficulté quand on développe un tel système est fortement influencée par l'attente que l'utilisateur place dans le travail effectué par l'ordinateur. L'ordinateur étant considéré comme un assistant dans le processus de création, on attend de lui qu'il soit 'assez intelligent' pour mériter ce rang. Habituellement, nous n'acceptons pas bien quand le résultat d'une telle assistance n'est pas satisfaisante. Cependant, le niveau d'attente et, par conséquence, de satisfaction, varie en fonction de l'utilisateur. Les utilisateurs novices ont tendance à être moins exigeants et sont satisfaits quand ils peuvent créer des résultats intéressants avec peu d'intervention humaine. Les utilisateurs professionnels, d'un autre côté, ont des besoins différents. Ils recherchent des logiciels assez performants pour automatiser leurs taches, mais qui leur laissent assez de contrôle sur le résultat obtenu. Pour cette catégorie d'utilisateurs, plus l'impact du logiciel sur le résultat est important, plus ils veulent avoir le contrôle sur la façon dont est obtenu ce résultat. Dans cette thèse, nous démontrons que l'ordinateur peut être un assistant précieux dans le processus de création visuel du moment que des systèmes d'interaction adaptés existent. L'adaptation est donc un aspect important car, à différents niveaux, les utilisateurs veulent pouvoir contrôler le résultat afin d'exprimer leur style et leur créativité. La thèse présente deux scénarios différents qui démontrent que la contrôlabilité joue un rôle majeur dans l'expressivité : une technique temps-réel pour grouper des scènes 3d dynamiques pour obtenir automatiquement un résultat sur lequel on peut facilement appliquer un style de rendu arbitraire; et plusieurs dérivées d'une primitive de dessin vectoriel appelée Diffusion Curves qui contraignent et contrôlent la création de dégradés de couleurs complexes. La thèse propose, d'un coté, des représentations mathématiques et algorithmiques adaptées avec différents niveaux de contrôle sur les algorithmes de rendu expressif qui manipulent des scènes bi et tridimensionnelles; et, d'un autre coté, de traduire ces outils en interface intuitive pour l'utilisateur.
Published: 2010

47. Building with Bricks: Cuda-based Gigavoxel Rendering

Author: Crassin, Cyril, Neyret, Fabrice, Eisemann, Elmar, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and Télécom ParisTech
Subjects: ComputingMilieux_MISCELLANEOUS, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract: International audience
Published: 2009

48. User-assisted intrinsic images

Author: Sylvain Paris, Frédo Durand, Adrien Bousseau, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Adobe Systems Inc. (Adobe Advanced Technology Labs), Adobe Systems Inc., Massachusetts Institute of Technology (MIT), Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science, and Durand, Fredo
Subjects: ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 02 engineering and technology, intrinsic images, 01 natural sciences, Image (mathematics), Upsampling, 010309 optics, Computational photography, Simple (abstract algebra), Component (UML), 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Computer vision, Mathematics, business.industry, reflectance illumination separation, 020207 software engineering, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Product (mathematics), 020201 artificial intelligence & image processing, Artificial intelligence, Closed-form expression, business, Energy (signal processing)
Abstract: For many computational photography applications, the lighting and materials in the scene are critical pieces of information. We seek to obtain intrinsic images, which decompose a photo into the product of an illumination component that represents lighting effects and a reflectance component that is the color of the observed material. This is an under-constrained problem and automatic methods are challenged by complex natural images. We describe a new approach that enables users to guide an optimization with simple indications such as regions of constant reflectance or illumination. Based on a simple assumption on local reflectance distributions, we derive a new propagation energy that enables a closed form solution using linear least-squares. We achieve fast performance by introducing a novel downsampling that preserves local color distributions. We demonstrate intrinsic image decomposition on a variety of images and show applications., National Science Foundation (U.S.) (NSF CAREER award 0447561), Institut national de recherche en informatique et en automatique (France) (Associate Research Team “Flexible Rendering”), Microsoft Research (New Faculty Fellowship), Alfred P. Sloan Foundation (Research Fellowship), Quanta Computer, Inc. (MIT-Quanta T Party)
Published: 2009

49. GigaVoxels: Voxels Come Into Play

Author: Crassin, Cyril, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Subjects: GigaVoxels, cache, GPU, ray-tracing, Voxels, ComputingMilieux_MISCELLANEOUS, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract: International audience; no abstract
Published: 2009

50. Représentations alternatives du détail visuel pour le rendu en temps-réel

Author: Baboud, Lionel, Acquisition, representation and transformations for image synthesis (ARTIS), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Université Joseph-Fourier - Grenoble I, François Sillion(Francois.Sillion@inria.fr), and Baboud, Lionel
Subjects: heightfield, alternative representations, rendu en temps-réel, light-field, GPU, real-time rendering, [INFO]Computer Science [cs], [INFO] Computer Science [cs], champ de hauteur, image-based rendering, représentations alternatives, rendu à base d'images
Abstract: This thesis takes place in the context of real-time image synthesis. It addresses the problem of efficient rendering for visual detail, main component of an image's realism. To cope with the complexity of visual detail it is necessary to possess representations which are adapted to objects that are to be rendered, together with capabilities of modern graphics processors. The first research effort concerns the use of relief for efficiently representing and rendering geometrical detail. The compact and structured representation of relief by an height map allows to design efficient and accurate rendering algorithms. We propose two of them: the first one can render animated reliefs, while the second one focuses on static ones by exploiting the possibility to preprocess the height map. We also develop a consideration on the use of relief for the representation of general surfaces, and present an application for real-time rendering of realistic water volumes. The second research effort focuses on non-surfacic representations, necessary when geometrical representations are inadequate or even non-existent. It is notably the case of distant objects or objects possessing a dense geometry, like a tree's foliage for example. The problem here is to be able to represent the visual aspect of an object without resorting to any geometrical model. We propose a method taking the light-field of an object as only input data, to determine the optimal parameters for an efficiently renderable representation., Cette thèse se place dans le cadre de la synthèse d'images en temps réel. Le problème auquel elle s'attaque est celui du rendu efficace du détail visuel, principal élément du réalisme d'une image. Pour faire face à la complexité du détail visuel, il est nécessaire de disposer de représentations adaptées à la fois aux objets que l'on cherche à rendre ainsi qu'aux capacités des processeurs graphiques actuels. Le premier axe de recherche porte sur l'utilisation du relief pour représenter et rendre efficacement du détail géométrique. La représentation compacte et structurée du relief par une carte hauteur permet la conception d'algorithmes de rendu exacts et efficaces. Nous en proposons deux~: le premier permet de rendre des reliefs dynamiques, alors que le second s'adresse aux reliefs statiques en exploitant la possibilité d'effectuer un pré-traitement sur la carte de hauteur. Nous développons aussi une réflexion sur l'utilisation du relief pour la représentation de surfaces quelconques, et présentons une application au rendu réaliste et en temps réel de volumes d'eau. Le deuxième axe de recherche se concentre sur les représentations non surfaciques, nécessaires lorsque les représentations géométriques sont inadaptées voire inexistantes. C'est le cas notamment des objets lointains ou des objets à géométrie dense, comme par exemple le feuillage d'un arbre. Le problème ici est d'être capable de représenter l'apparence d'un objet, sans recourir à un modèle géométrique. Nous proposons une méthode permettant, à partir de la seule donnée du light-field d'un objet, de déterminer les paramètres optimaux d'une représentation adaptée pour le rendu.
Published: 2009

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Journal

Database

Publisher

200 results on '"Acquisition, representation and transformations for image synthesis (ARTIS)"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources