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Poster Session 5

Poster Session 5

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Poster Session 5

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  1. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Poster Session 5 Volume Data Processing and Scientific Visualization

  2. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Vector Quantization for Feature-Preserving Volume Filtering Balázs Csébfalvi, József Koloszár, Zsolt Tarján Department of Control Engineering and Information TechnologyBudapest University of Technology and Economics

  3. Vector Quantization for Feature-Preserving Volume Filtering Noisy CT data acquired at low radiation dose The same data filtered by vector quantization

  4. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Non-linear Integration of DTI-based Fiber Tracts into Standard 3D MR Data D. Merhof , P. Hastreiter , G. Soza , M. Stamminger , C. Nimsky 1,2 1,2 1,2 2 1 Neurocenter, Dept. of NeurosurgeryComputer Graphics Group, Univ. of Erlangen 1 2

  5. Registration Transformation Non-linear Integration of DTI-basedFiber Tracts into Standard 3D MR Data • Brain tumor surgery: • Preoperative planning: Spatial relation tumor - fibers • Diffusion Tensor Imaging (DTI): • Enables computation of neural pathways • Problem: Image distortions of DTI sequence • Approach: • Non-linear registration with undistorted T1 weighed MR dataset • Results: • Identify and account for areas of high distortion DTI T1

  6. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Flexible Direct Multi-Volume Rendering in Dynamic Scenes Sören Grimm, Stefan Bruckner, Armin Kanitsar, and Eduard Gröller Vienna University of Technology

  7. Flexible Direct Multi-Volume Rendering in Dynamic Scenes • Efficient rendering of multiple intersecting volumes • Object-space decomposition into single and multi-volume ray-segments V-Object I V-Objects A1 A B1 B2 B3 B I∩ II C1 C2 C3 C Data sources V-Object II

  8. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Illustrating Magnetic Field Lines using a Discrete Particle Model Thomas Klein and Thomas Ertl Visualization and Interactive Systems GroupUniversity of Stuttgart

  9. Illustrating Magnetic Field Lines using a Discrete Particle Model • Goal: Illustrations that resemble the appearance of real experiments • Modeling of particles in a magnetic field • Computational physics approach • Molecular Dynamics • Magnetostatic n-body interaction • Point-based rendering • Minimal amount of geometry • Seamless zooming

  10. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Fourier Volume Rendering on the GPUusing a Split-Stream-FFT Thomas Jansen Research Center caesar, Bonn, Germany

  11. FVR on the GPU 1. Fast Fourier Transform in 3D: Preprocessing • Is done on the CPU once and uploaded to the GPU 2. Extract 2D Slice: High-Quality Interpolation • Linear/cubic interpolation cause aliasing artifacts • Interpolation on the GPU via Lancosz-filtering 3. Fast Fourier Transform in 2D: Split-Stream-FFT • Efficient mapping of the recursive FFT structure • Split the FFT-butterfly operation to utilize parallelism • Bit reversal/tangling is done via texture coordinates • Complex- and Real-DFT and -DHT implemented

  12. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA The Voxel-Sweep: A Boundary-based Algorithm for Object Segmentation and Connected-Components Detection Itay Cohen Dan Gordon Dept. of Computer Science, University of Haifa

  13. The Voxel-Sweep • Operates in one sweep on voxels. • Detects isosurfaces as in Marching Cubes, using Union-Finddata structure to partition surfaces into connected components. • Time: Only 2% more than MC. • Associates inner surfaces (holes) with their respective outer surface. • Exactvolumeandsurface areasof components can be computed; useful for medical purposes and noise reduction (eliminating “small” parts). • Work in progress:speedup.

  14. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA SMART: An Efficient Technique for Massive Terrain Visualization from Out-of-core Xiaohong Bao, Renato Pajarola, Michael Shafae University of California, Irvine

  15. SMART: An Efficient Technique for Massive Terrain Visualization from Out-of-core • Per-vertex live-range removes 80% to 98% of complex per-vertex LOD-selection computation in each frame • LOD mesh generation and overall rendering speed-ups range from 5 to 10 for a wide range of frame coherency

  16. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Grid-Independent Detection of Closed Stream Lines in 2D Vector Fields H. Theisel, T. Weinkauf, H.-C. Hege, H.-P. Seidel MPI Informatik Saarbrücken, GermanyZuse Institute (ZIB) Berlin, Germany

  17. Closed Stream lines • Global topological feature! • Detect closed stream lines of 2D vector fields @intersect stream surfaces of 3D vector fields

  18. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Fast and Accurate Ray-Voxel Intersection Techniques for Iso-Surface Ray Tracing Gerd Marmitt, A. Kleer, I. Wald, H. Friedrich, and P. Slusallek Computer Graphics LabSaarland University

  19. Iso-Voxel-Intersection • Voxel-Intersection algorithms varies largely in speed and accuracy: • Analytical Inversion: 1.56 int./sec • good quality but very slow • Neubauer’s Method: 2.93 int./sec • fast but produces holes • New Approach: 2.76 int./sec • good quality and fast • Advantages of Ray Tracing: • Easy shadows, reflection, refract. • Mixed surface-volume rendering

  20. 9th International Fall Workshop VISION, MODELING, AND VISUALIZATION 2004 November 16 - 18, 2004Stanford (California), USA Pre-Integrated Non-Photorealistic Volume Rendering Michael Meissner, Klaus Engel Viatronix Inc., Siemens Corporate Research

  21. Pre-Integrated NPVR Pre-Integration of TF Pre-Integration of curvature Pre-Integration of silhouettes Result Pre-Integration of gradient magnitude