TY - GEN A1 - Rosanwo, Olufemi A1 - Petz, Christoph A1 - Prohaska, Steffen A1 - Hotz, Ingrid A1 - Hege, Hans-Christian T1 - Dual Streamline Seeding - Method and Implementation N2 - This work introduces a novel streamline seeding technique based on dual streamlines that are orthogonal to the vector field, instead of tangential. The greedy algorithm presented here produces a net of orthogonal streamlines that is iteratively refined resulting in good domain coverage and a high degree of continuity and uniformity. The algorithm is easy to implement and efficient, and it naturally extends to curved surfaces. N2 - In dieser Arbeit wird eine neue Strategie zur Platzierung von Stromlinien vorgestellt. Hierzu werden zusätzliche duale Stromlinien verwendet, die --im Gegensatz zur üblichen Definition-- orthogonal zum Vektorfeld verlaufen. Der vorgestellte Greedy-Algorithmus berechnet ein Netz aus orthogonalen Stromlinien, welches iterativ verfeinert wird, was zu einer guten Abdeckung der Domäne und einer gleichmäßigen Verteilung der Stromlinien führt. Es handelt sich um einen einfach zu implementierenden und effizienten Algorithmus, der direkt auf gekrümmten Oberflächen anwendbar ist. T3 - ZIB-Report - 08-49 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-11032 SN - 1438-0064 ER - TY - GEN A1 - Wiebel, Alexander A1 - Vos, Frans M. A1 - Hege, Hans-Christian T1 - Perception-Oriented Picking of Structures in Direct Volumetric Renderings N2 - Radiologists from all application areas are trained to read slice-based visualizations of 3D medical image data. Despite the numerous examples of sophisticated three-dimensional renderings, especially all variants of direct volume rendering, such methods are often considered not very useful by radiologists who prefer slice-based visualization. Just recently there have been attempts to bridge this gap between 2D and 3D renderings. These attempts include specialized techniques for volume picking that result in repositioning slices. In this paper, we present a new volume picking technique that, in contrast to previous work, does not require pre-segmented data or metadata. The positions picked by our method are solely based on the data itself, the transfer function and, most importantly, on the way the volumetric rendering is perceived by viewers. To demonstrate the usefulness of the proposed method we apply it for automatically repositioning slices in an abdominal MRI scan, a data set from a flow simulation and a number of other volumetric scalar fields. Furthermore we discuss how the method can be implemented in combination with various different volumetric rendering techniques. T3 - ZIB-Report - 11-45 KW - DVR KW - picking KW - pointing KW - direct volume rendering Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-14343 SN - 1438-0064 ER - TY - GEN A1 - Klindt, Marco A1 - Baum, Daniel A1 - Prohaska, Steffen A1 - Hege, Hans-Christian T1 - iCon.text – a customizable iPad app for kiosk applications in museum exhibitions N2 - We present iCon.text, a kiosk platform for the iPad centered around artefacts, whose content and layout can be tailored without programming skills for specific museum exhibitions. The central metaphor to access information is a virtual postcard with one front and a customizable number of back sides that provide details about exhibits to museum visitors in textual and image form. Back sides can link to others cards. Access to these postcards is possible through one or more navigation views that can be navigated to from a navigation bar. The entry point to the application is designed as a multitouch interactive pile of cards in a playful manner that allows visitors of any age an easy approach to the presentation and interaction metaphor. To directly access a certain postcard, a mosaic view can be uitilized to provide an overview about all available exhibits. A category view groups postcards into themes. Locating artefacts on a zoomable map or exhibition floor plan allows for conveying information about spatial contexts between different objects and their location. Furthermore, contexts can be illustrated with a two stage view comprising an overview and corresponding detail views to provide further insights into the spatial, temporal, and thematic contexts of artefacts. The application scaffolding allows the design of bilingual presentations to support exhibitions with an international audience. The logo of the presenting institution or exhibition can be incorporated to display the the kiosk's corporate design branding and to access an imprint or further informations. Usage is logged into files to provide a basis for extracting statistical information about the usage. The details about the exhibits are presented as images and as such impose no limit to the design choices made by the content provider or exhibition designer. The application (enhanced with a panoramic view) has been integrated successfully into a large special exhibition about the ancient city of Pergamon 2011/2012 at the Pergamon Museum Berlin within the interdisciplinary project "Berlin Sculpture Network". T3 - ZIB-Report - 13-07 KW - HCI KW - Cultural Heritage KW - Kiosk application KW - iPad Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-17731 SN - 1438-0064 ER - TY - BOOK A1 - Hege, Hans-Christian A1 - (Eds.), Konrad T1 - Mathematical Visualization - Algorithms, Applications, and Numerics Y1 - 1998 SN - ISBN 3-540-63991-8 PB - Springer CY - Heidelberg ER - TY - BOOK A1 - Hege, Hans-Christian A1 - Polthier, Konrad T1 - VideoMath - Festival at ICM 98 T3 - Springer VideoMath Y1 - 1998 SN - 978-3-540-21385-7 ER - TY - BOOK A1 - Hege, Hans-Christian A1 - (Eds.), Konrad T1 - Visualization and Mathematics - Experiments, Simulations and Environments Y1 - 1997 SN - ISBN 3-540-61269-6 PB - Springer-Verlag, Berlin/Heidelberg ER - TY - GEN A1 - Ehlke, Moritz A1 - Ramm, Heiko A1 - Lamecker, Hans A1 - Hege, Hans-Christian A1 - Zachow, Stefan T1 - Fast Generation of Virtual X-ray Images from Deformable Tetrahedral Meshes N2 - We propose a novel GPU-based approach to render virtual X-ray projections of deformable tetrahedral meshes. These meshes represent the shape and the internal density distribution of a particular anatomical structure and are derived from statistical shape and intensity models (SSIMs). We apply our method to improve the geometric reconstruction of 3D anatomy (e.g.\ pelvic bone) from 2D X-ray images. For that purpose, shape and density of a tetrahedral mesh are varied and virtual X-ray projections are generated within an optimization process until the similarity between the computed virtual X-ray and the respective anatomy depicted in a given clinical X-ray is maximized. The OpenGL implementation presented in this work deforms and projects tetrahedral meshes of high resolution (200.000+ tetrahedra) at interactive rates. It generates virtual X-rays that accurately depict the density distribution of an anatomy of interest. Compared to existing methods that accumulate X-ray attenuation in deformable meshes, our novel approach significantly boosts the deformation/projection performance. The proposed projection algorithm scales better with respect to mesh resolution and complexity of the density distribution, and the combined deformation and projection on the GPU scales better with respect to the number of deformation parameters. The gain in performance allows for a larger number of cycles in the optimization process. Consequently, it reduces the risk of being stuck in a local optimum. We believe that our approach contributes in orthopedic surgery, where 3D anatomy information needs to be extracted from 2D X-rays to support surgeons in better planning joint replacements. T3 - ZIB-Report - 13-38 KW - digitally reconstructed radiographs KW - volume rendering KW - mesh deformation KW - statistical shape and intensity models KW - image registration KW - GPU acceleration Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-41896 SN - 1438-0064 ER - TY - CHAP A1 - Gladilin, Evgeny A1 - Zachow, Stefan A1 - Deuflhard, Peter A1 - Hege, Hans-Christian ED - Mun, Seong T1 - Validation of a Linear Elastic Model for Soft Tissue Simulation in Craniofacial Surgery T2 - Proc. SPIE Medical Imaging 2001 Y1 - 2001 U6 - https://doi.org/10.1117/12.428061 VL - 4319 SP - 27 EP - 35 CY - San Diego, USA ER - TY - CHAP A1 - Gladilin, Evgeny A1 - Zachow, Stefan A1 - Hege, Hans-Christian A1 - Deuflhard, Peter T1 - FE-based heuristic approach for the estimation of person-specific facial mimics T2 - Proceedings of Euro-Par 2001: 5-th International Symposium on Computer Methods Y1 - 2001 CY - Rome, Italy ER - TY - CHAP A1 - Allen, Gabrielle A1 - Benger, Werner A1 - Goodale, Tom A1 - Hege, Hans-Christian A1 - Lanfermann, Gerd A1 - Merzky, André A1 - Radke, Thomas A1 - Seidel, Edward A1 - Shalf, John T1 - The Cactus Code: A Problem Solving Environment for the Grid T2 - High Performance Distributed Computing (HPDC-2000) Y1 - 2000 U6 - https://doi.org/10.1109/HPDC.2000.868657 SP - 253 EP - 260 ER -