Search Results

Now showing 1 - 10 of 12
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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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    Energy Aware Color Sets
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Chuang, Johnson; Weiskopf, Daniel; Moeller, Torsten
    We present a design technique for colors with the purpose of lowering the energy consumption of the display device. Our approach is based on a screen space variant energy model. The result of our design is a set of distinguishable iso-lightness colors guided by perceptual principles. We present two variations of our approach. One is based on a set of discrete user-named (categorical) colors, which are analyzed according to their energy consumption. The second is based on the constrained continuous optimization of color energy in the perceptually uniform CIELAB color space. We quantitatively compare our two approaches with a traditional choice of colors, demonstrating that we typically save approximately 40 percent of the energy. The color sets are applied to examples from the 2D visualization of nominal data and volume rendering of 3D scalar fields.
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    Visualization Curriculum Panel - or The Changes We Have Made to Our Visualization Courses Over the Last 10 Years
    (The Eurographics Association, 2012) Domik, Gitta; Ebert, David; Kohlhammer, Jörn; Rushmeier, Holly; Santos, Beatriz Sousa; Weiskopf, Daniel; Giovanni Gallo and Beatriz Sousa Santos
    The last ten years have seen profound changes in algorithms, techniques, and applications of visualization. Additionally, we see changes in the sophistication and expectations of our students in visualization courses. This panel will reflect changes in teaching visualization courses through the personal reflections of renowned researchers and educators on their alterations on course content over the past 10 years
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    Shadow Mapping Based on Dual Depth Layers
    (Eurographics Association, 2003) Weiskopf, Daniel; Ertl, Thomas
    Shadow maps are a widely used means for the generation of shadows although they exhibit aliasing artifacts and problems of numerical precision. In this paper we extend the concept of a single shadow map by introducing dual shadow maps, which are based on the two depth layers that are closest to the light source. Our shadow algorithm takes into account these two depth values and computes an adaptive depth bias to achieve a robust determination of shadowed regions. Dual depth mapping only modifies the construction of the shadow map and can therefore be combined with other extensions such as filtering, perspective shadow maps, or adaptive shadow maps. Our approach can be mapped to graphics hardware for interactive applications and can also be used in high-quality software renderers.
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    Pathline Glyphs
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Hlawatsch, Marcel; Sadlo, Filip; Jang, Hajun; Weiskopf, Daniel; B. Levy and J. Kautz
    Visualization of pathlines is common and highly relevant for the analysis of unsteady flow. However, pathlines can intersect, leading to visual clutter and perceptual issues. This makes it intrinsically difficult to provide expressive visualizations of the entire domain by an arrangement of multiple pathlines, in contrast to well-established streamline placement techniques. We present an approach to reduce these problems. It is inspired by glyph-based visualization and small multiples: we partition the domain into cells, each corresponding to a downscaled version of the entire domain. Inside these cells, a single downscaled pathline is drawn. On the overview scale, our pathline glyphs lead to emergent visual patterns that provide insight into time-dependent flow behavior. Zooming-in allows us to analyze individual pathlines in detail and compare neighboring lines. The overall approach is complemented with a context-preserving zoom lens and interactive pathline-based exploration. While we primarily target the visualization of 2D flow, we also address the extension to 3D. Our evaluation includes several examples, comparison to other flow visualization techniques, and a user study with domain experts.
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    Geo-Spatial Context-Aware Visualization
    (The Eurographics Association, 2009) Weiskopf, Daniel; D. Ebert and J. Krüger
    Mobile computer systems equipped with wireless communication and sensor technology-such as mobile phones with cameras-have become widely available. Context information, for example the user's current location or their physical environment, plays an increasingly important role in simplifying the interaction between users and such mobile information systems. A generic framework for federating heterogeneous spatial context models is briefly described. The federated information serves as basis for the visualization of spatially referenced data. Visualization challenges include efficient rendering on mobile devices, automatic adaptation of visualization techniques to context information, as well as consideration of the quality of context in the form of uncertainty visualization.
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    Flow Visualization by Texture Advection
    (Eurographics Association, 2003) Weiskopf, Daniel
    • Vector field visualization: indirectly by tracing particles • Issues: – Seed point positioning – Dense vs. sparse representation – Steady vs. unsteady flow fields – Visualization speed
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    State of the Art of Parallel Coordinates
    (The Eurographics Association, 2013) Heinrich, Julian; Weiskopf, Daniel; M. Sbert and L. Szirmay-Kalos
    This work presents a survey of the current state of the art of visualization techniques for parallel coordinates. It covers geometric models for constructing parallel coordinates and reviews methods for creating and understanding visual representations of parallel coordinates. The classification of these methods is based on a taxonomy that was established from the literature and is aimed at guiding researchers to find existing techniques and identifying white spots that require further research. The techniques covered in this survey are further related to an established taxonomy of knowledge-discovery tasks to support users of parallel coordinates in choosing a technique for their problem at hand. Finally, we discuss the challenges in constructing and understanding parallel-coordinates plots and provide some examples from different application domains.
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    Video Visualization
    (The Eurographics Association, 2013) Borgo, Rita; Chen, Min; Höferlin, Markus; Kurzhals, Kuno; Legg, Phil; Walton, Simon; Weiskopf, Daniel; Diego Gutierrez and Karol Myszkowski
    Video data, generated by the entertainment industry, security and traffic cameras, video conferencing systems, video emails, and so on, is particularly time-consuming to process by human beings. The field of visualization has provided this challenging problem with a collection of techniques that transform videos to different visual forms in order to reduce the time required to watch the video. In this tutorial, we will introduce the concept of video visualization, and several elementary techniques for processing and rendering a video into a compact visual representation. We will describe a family of visual representations, a set of insight obtained from empirical studies, and a collection of applications.
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    Eye Tracking Visualization
    (The Eurographics Association, 2015) Burch, Michael; Blascheck, Tanja; Kurzhals, Kuno; Pflüger, Hermann; Raschke, Michael; Weiskopf, Daniel; Pfeiffer, Thies; M. Zwicker and C. Soler
    Eye tracking has become a widely used method to analyze user behavior in marketing, neuroscience, human-computer interaction, and visualization research. Apart from measuring completion times and recording accuracy rates of correctly given answers during the performance of visual tasks in classical controlled user experiments, eye tracking-based evaluations provide additional information on how visual attention is distributed and changing for a presented stimulus. Due to the wide field of applications of eye tracking and various kinds of research questions, different approaches have been developed to analyze eye tracking data such as statistical algorithms (either descriptive or inferential), string editing algorithms, visualization-related techniques, and visual analytics techniques. Regardless of whether statistical or visual methods are used for eye tracking data analysis, a large amount of data generated during eye tracking experiments has to be handled.