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    A Survey on Video-based Graphics and Video Visualization
    (The Eurographics Association, 2011) Borgo, Rita; Chen, Min; Daubney, Ben; Grundy, Edward; Heidemann, Gunther; Höferlin, Benjamin; Höferlin, Markus; Jänicke, Heike; Weiskopf, Daniel; Xie, Xianghua; N. John and B. Wyvill
    In recent years, a collection of new techniques which deal with video as input data, emerged in computer graphics and visualization. In this survey, we report the state of the art in video-based graphics and video visualization. We provide a comprehensive review of techniques for making photo-realistic or artistic computer-generated imagery from videos, as well as methods for creating summary and/or abstract visual representations to reveal important features and events in videos. We propose a new taxonomy to categorize the concepts and techniques in this newlyemerged body of knowledge. To support this review, we also give a concise overview of the major advances in automated video analysis, as some techniques in this field (e.g., feature extraction, detection, tracking and so on) have been featured in video-based modeling and rendering pipelines for graphics and visualization.
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    SoundRiver: Semantically-Rich Sound Illustration
    (The Eurographics Association and Blackwell Publishing Ltd, 2010) Jaenicke, H.; Borgo, R.; Mason, J. S. D.; Chen, M.
    Sound is an integral part of most movies and videos. In many situations, viewers of a video are unable to hear the sound track, for example, when watching it in a fast forward mode, viewing it by hearing-impaired viewers or when the plot is given as a storyboard. In this paper, we present an automated visualization solution to such problems. The system first detects the common components (such as music, speech, rain, explosions, and so on) from a sound track, then maps them to a collection of programmable visual metaphors, and generates a composite visualization. This form of sound visualization, which is referred to as SoundRiver, can be also used to augment various forms of video abstraction and annotated key frames and to enhance graphical user interfaces for video handling software. The SoundRiver conveys more semantic information to the viewer than traditional graphical representations of sound illustration, such as phonoautographs, spectrograms or artistic audiovisual animations.
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    Example-based Interpolation and Synthesis of Bidirectional Texture Functions
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Ruiters, Roland; Schwartz, Christopher; Klein, Reinhard; I. Navazo, P. Poulin
    Bidirectional Texture Functions (BTF) have proven to be a well-suited representation for the reproduction of measured real-world surface appearance and provide a high degree of realism. We present an approach for designing novel materials by interpolating between several measured BTFs. For this purpose, we transfer concepts from existing texture interpolation methods to the much more complex case of material interpolation. We employ a separation of the BTF into a heightmap and a parallax compensated BTF to cope with problems induced by parallax, masking and shadowing within the material. By working only on the factorized representation of the parallax compensated BTF and the heightmap, it is possible to efficiently perform the material interpolation. By this novel method to mix existing BTFs, we are able to design plausible and realistic intermediate materials for a large range of different opaque material classes. Furthermore, it allows for the synthesis of tileable and seamless BTFs and finally even the generation of gradually changing materials following user specified material distribution maps.
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    PhD Education Through Apprenticeship
    (The Eurographics Association, 2011) Patel, Daniel; Gröller, M. Eduard; Bruckner, Stefan; S. Maddock and J. Jorge
    We describe and analyze the PhD education in the visualization group at the Vienna University of Technology and set the education in a larger perspective. Four central mechanisms drive the PhD education in Vienna. They are: to require an article-based PhD; to give the student freedom to choose research direction; to let students work in shared offices towards joint deadlines; and to involve students in reviewing articles. This paper describes these mechanisms in detail and illustrates their effect.
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    Designing Multi-projector VR Systems: From Bits to Bolts
    (The Eurographics Association, 2010) Soares, Luciano Pereira; Jorge, Joaquim A.; Dias, José Miguel Salles; Raposo, Alberto; Araújo, Bruno R. de; U. Assarsson and D. Weiskopf
    This tutorial will present how to design, construct and manage immersive multi-projection environments, covering everything from projection technologies to computer hardware and software integration. Topics as tracking, multimodal interactions and audio are going to be explored. At the end, we are going to present important design decisions from real cases. <br> The objective of this tutorial is to give an introduction to the issues to consider when planning the installation of a multi-projection environment for researchers and professionals in the computer graphics and virtual reality field. No previous knowledge is necessary in the audience for the tutorial, except for basic knowledge of computer graphics and virtual reality.
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    A Film Balloon Design System Integrated with Shell Element Simulation
    (The Eurographics Association, 2010) Furuta, Yohsuke; Umetani, Nobuyuki; Mitani, Jun; Igarashi, Takeo; Fukui, Yukio; H. P. A. Lensch and S. Seipel
    CAD systems that have user-friendly interfaces for assisting ordinary people to design objects is becoming common. Most of these systems combine a sketch interface with physical simulation. In this paper, we propose a system for designing balloons made of non-stretchy material such as aluminum foil, plastic film and paper. We implemented the system by using a finite element method that is based on discrete Kirchhoff triangle (DKT) shell elements and a sketch interface that enables users to easily design the realistic shape of an inflated balloon. The 2D pattern for the balloon design is generated automatically by our system. We evaluated our system by a user study with six elementary school children and their parents. These users designed target objects and responded to a questionnaire.
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    Dynamic 2D/3D Registration
    (The Eurographics Association, 2014) Bouaziz, Sofien; Tagliasacchi, Andrea; Pauly, Mark; Nicolas Holzschuch and Karol Myszkowski
    Image and geometry registration algorithms are an essential component of many computer graphics and computer vision systems. With recent technological advances in RGB-D sensors, such as the Microsoft Kinect or Asus Xtion Live, robust algorithms that combine 2D image and 3D geometry registration have become an active area of research. The goal of this course is to introduce the basics of 2D/3D registration algorithms and to provide theoretical explanations and practical tools to design computer vision and computer graphics systems based on RGB-D devices. To illustrate the theory and demonstrate practical relevance, we briefly discuss three applications: rigid scanning, non-rigid modeling, and realtime face tracking. Our course targets researchers and computer graphics practitioners with a background in computer graphics and/or computer vision. An up-to-date version of the course notes as well as slides and source code can be found at http://lgg.epfl.ch/2d3dRegistration.
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    Recent Advances in Adaptive Sampling and Reconstruction for Monte Carlo Rendering
    (The Eurographics Association and John Wiley & Sons Ltd., 2015) Zwicker, Matthias; Jarosz, Wojciech; Lehtinen, Jaakko; Moon, Bochang; Ramamoorthi, Ravi; Rousselle, Fabrice; Sen, Pradeep; Soler, Cyril; Yoon, Sungeui E.; K. Hormann and O. Staadt
    Monte Carlo integration is firmly established as the basis for most practical realistic image synthesis algorithms because of its flexibility and generality. However, the visual quality of rendered images often suffers from estimator variance, which appears as visually distracting noise. Adaptive sampling and reconstruction algorithms reduce variance by controlling the sampling density and aggregating samples in a reconstruction step, possibly over large image regions. In this paper we survey recent advances in this area. We distinguish between “a priori” methods that analyze the light transport equations and derive sampling rates and reconstruction filters from this analysis, and “a posteriori” methods that apply statistical techniques to sets of samples to drive the adaptive sampling and reconstruction process. They typically estimate the errors of several reconstruction filters, and select the best filter locally to minimize error. We discuss advantages and disadvantages of recent state-of-the-art techniques, and provide visual and quantitative comparisons. Some of these techniques are proving useful in real-world applications, and we aim to provide an overview for practitioners and researchers to assess these approaches. In addition, we discuss directions for potential further improvements.
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    Perceptually Motivated Real-Time Compression of Motion Data Enhanced by Incremental Encoding and Parameter Tuning
    (The Eurographics Association, 2013) Firouzmanesh, Amirhossein; Cheng, Irene; Basu, Anup; M.- A. Otaduy and O. Sorkine
    We address the problem of efficient real-time motion data compression considering human perception. Using incremental encoding plus a database of motion primitives for each key point, our method achieves a higher or competitive compression rate with less online overhead. Trade-off between visual quality and bandwidth usage can be tuned by varying a single threshold value. A user study was performed to measure the sensitivity of human subjects to reconstruction errors in key rotation angles. Based on these evaluations we are able to perform lossy compression on the motion data without noticeable degradation in rendered qualities. While achieving real-time performance, our technique outperforms other methods in our experiments by achieving a compression ratio exceeding 50 : 1 on regular sequences.
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    An Error Bound for Decoupled Visibility with Application to Relighting
    (The Eurographics Association, 2011) Schwenk, Karsten; Fellner, Dieter W.; N. Avis and S. Lefebvre
    Monte Carlo estimation of direct lighting is often dominated by visibility queries. If an error is tolerable, the calculations can be sped up by using a simple scalar occlusion factor per light source to attenuate radiance, thus decoupling the expensive estimation of visibility from the comparatively cheap sampling of unshadowed radiance and BRDF. In this paper we analyze the error associated with this approximation and derive an upper bound. We demonstrate in a simple relighting application how our result can be used to reduce noise by introducing a controlled error if a reliable estimate of the visibility is already available.