TY - CHAP A1 - Kuhn, Alexander A1 - Lindow, Norbert A1 - Günther, Tobias A1 - Wiebel, Alexander A1 - Theisel, Holger A1 - Hege, Hans-Christian T1 - Trajectory Density Projection for Vector Field Visualization T2 - EuroVis 2013, short papers. M. Hlawitschka, Tino Weinkauf (eds.) Y1 - 2013 UR - http://vc.cs.ovgu.de/files/publications/2013/Kuhn_2013_EUROVIS.pdf U6 - https://doi.org/10.2312/PE.EuroVisShort.EuroVisShort2013.031-035 SP - 31 EP - 35 ER - TY - GEN A1 - Wiebel, Alexander A1 - Koch, Stefan A1 - Scheuermann, Gerik ED - Peikert, Ronald ED - Hauser, Helwig ED - Carr, Hamish ED - Fuchs, Raphael T1 - Glyphs for Non-Linear Vector Field Singularities T2 - Topological Methods in Data Analysis and Visualization II Y1 - 2011 SP - 177 EP - 190 PB - Springer CY - Berlin ER - TY - GEN A1 - Wiebel, Alexander A1 - Hege, Hans-Christian A1 - Ziech, Manon A1 - Caan, Matthan A1 - Stoker, Jaap A1 - Vos, Frans T1 - DCE-MRI-oriented Volume Rendering for Monitoring of Crohn’s Disease. T2 - BioVis 2011 Abstracts, 1st IEEE Symposium on Biological Data Visualization Y1 - 2011 ER - TY - CHAP A1 - Goldau, Mathias A1 - Wiebel, Alexander A1 - Gorbach, Nico A1 - Melzer, Corina A1 - Hlawitschka, Mario A1 - Scheuermann, Gerik A1 - Tittgemeyer, Marc T1 - Fiber Stippling: An Illustrative Rendering for Probabilistic Diffusion Tractography Combinatorial Vector Field Topology in 3 Dimensions T2 - 1st IEEE Symposium on Biological Data Visualization Y1 - 2011 U6 - https://doi.org/10.1109/BioVis.2011.6094044 target SP - 23 EP - 30 ER - TY - CHAP A1 - Wiebel, Alexander A1 - Preis, Philipp A1 - Vos, Frans A1 - Hege, Hans-Christian ED - Hlawitschka, Mario ED - Weinkauf, Tino T1 - 3D Strokes on Visible Structures in Direct Volume Rendering T2 - EuroVis - Short Papers Y1 - 2013 U6 - https://doi.org/10.2312/PE.EuroVisShort.EuroVisShort2013.091-095 SP - 91 EP - 95 PB - Eurographics Association ER - TY - CHAP A1 - Koch, Stefan A1 - Wiebel, Alexander A1 - Kasten, Jens A1 - Hlawitschka, Mario T1 - Visualizing Linear Neighborhoods in Non-Linear Vector Fields T2 - Proceedings of the IEEE Pacific Visualization Symposium Y1 - 2013 SP - 249 EP - 256 CY - Sydney, Australia ER - TY - GEN A1 - Homberg, Ulrike A1 - Baum, Daniel A1 - Wiebel, Alexander A1 - Prohaska, Steffen A1 - Hege, Hans-Christian ED - Bremer, Peer-Timo ED - Hotz, Ingrid ED - Pascucci, Valerio ED - Peikert, Ronald T1 - Definition, Extraction, and Validation of Pore Structures in Porous Materials BT - Theory, Algorithms, and Applications T2 - Topological Methods in Data Analysis and Visualization III Y1 - 2014 U6 - https://doi.org/10.1007/978-3-319-04099-8_15 SP - 235 EP - 248 PB - Springer ER - TY - GEN A1 - Homberg, Ulrike A1 - Baum, Daniel A1 - Wiebel, Alexander A1 - Prohaska, Steffen A1 - Hege, Hans-Christian T1 - Definition, Extraction, and Validation of Pore Structures in Porous Materials N2 - An intuitive and sparse representation of the void space of porous materials supports the efficient analysis and visualization of interesting qualitative and quantitative parameters of such materials. We introduce definitions of the elements of this void space, here called pore space, based on its distance function, and present methods to extract these elements using the extremal structures of the distance function. The presented methods are implemented by an image processing pipeline that determines pore centers, pore paths and pore constrictions. These pore space elements build a graph that represents the topology of the pore space in a compact way. The representations we derive from μCT image data of realistic soil specimens enable the computation of many statistical parameters and, thus, provide a basis for further visual analysis and application-specific developments. We introduced parts of our pipeline in previous work. In this chapter, we present additional details and compare our results with the analytic computation of the pore space elements for a sphere packing in order to show the correctness of our graph computation. T3 - ZIB-Report - 13-56 Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-42510 SN - 1438-0064 ER - TY - CHAP A1 - Hlawitschka, Mario A1 - Hotz, Ingrid A1 - Kratz, Andrea A1 - Marai, G. Elisabeta A1 - Moreno, Rodrigo A1 - Scheuermann, Gerik A1 - Stommel, Markus A1 - Wiebel, Alexander A1 - Zhang, Eugene ED - Westin, Carl-Frederic ED - Burgeth, Bernhard ED - Vilanova, Anna T1 - Top Challenges in the Visualization of Engineering Tensor Fields T2 - Visualization and Processing of Tensors and Higher-Order Descriptors for Multi-Field Data Y1 - 2014 SP - 3 EP - 15 PB - Springer ER - TY - JOUR A1 - Wiebel, Alexander A1 - Vos, Frans A1 - Foerster, David A1 - Hege, Hans-Christian T1 - WYSIWYP: What You See Is What You Pick JF - IEEE Transactions on Visualization and Computer Graphics Y1 - 2012 U6 - https://doi.org/10.1109/TVCG.2012.292 VL - 18 IS - 12 SP - 2236 EP - 2244 ER - TY - CHAP A1 - Vos, Franciscus A1 - Tielbeek, Jeroen A1 - Naziroglu, Robiel A1 - Li, Zhang A1 - Schueffler, Peter A1 - Mahapatra, Dwarikanath A1 - Wiebel, Alexander A1 - Lavini, Christina A1 - Buhmann, Joachim A1 - Hege, Hans-Christian A1 - Stoker, Jaap A1 - van Vliet, Lucas T1 - Computational modeling for assessment of IBD: to be or not to be? T2 - 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) Y1 - 2012 U6 - https://doi.org/10.1109/EMBC.2012.6346837 SP - 3974 EP - 3977 ER - TY - CHAP A1 - Stoppel, Sergej A1 - Hege, Hans-Christian A1 - Wiebel, Alexander T1 - Visibility-driven depth determination of surface patches in direct volume rendering T2 - EuroVis - Short Papers 2014 N2 - This paper presents an algorithm called surfseek for selecting surfaces on the most visible features in direct volume rendering (DVR). The algorithm is based on a previously published technique (WYSIWYP) for picking 3D locations in DVR. The new algorithm projects a surface patch on the DVR image, consisting of multiple rays. For each ray the algorithm uses WYSIWYP or a variant of it to find the candidates for the most visible locations along the ray. Using these candidates the algorithm constructs a graph and computes a minimum cut on this graph. The minimum cut represents a visible and typically rather smooth surface. In the last step the selected surface is displayed. We provide examples for results using artificially generated and real-world data sets. Y1 - 2014 U6 - https://doi.org/10.2312/eurovisshort.20141164 SP - 97 EP - 101 ER - TY - GEN A1 - Wiebel, Alexander A1 - Müller, Cornelius A1 - Garth, Christoph A1 - Knösche, Thomas ED - Westin, Carl-Frederic ED - Burgeth, Bernhard ED - Vilanova, Anna T1 - A System for Combined Visualization of EEG and Diffusion Tensor Imaging Tractography Data T2 - Visualization and Processing of Tensors and Higher-Order Descriptors for Multi-field Data Y1 - 2014 SP - 325 EP - 337 PB - Springer 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 - Stoppel, Sergej A1 - Hege, Hans-Christian A1 - Wiebel, Alexander T1 - Visibility-Driven Depth Determination of Surface Patches in Direct Volume Rendering N2 - This paper presents an algorithm called surfseek for selecting surfaces on the most visible features in direct volume rendering (DVR). The algorithm is based on a previously published technique (WYSIWYP) for picking 3D locations in DVR. The new algorithm projects a surface patch on the DVR image, consisting of multiple rays. For each ray the algorithm uses WYSIWYP or a variant of it to find the candidates for the most visible locations along the ray. Using these candidates the algorithm constructs a graph and computes a minimum cut on this graph. The minimum cut represents a very visible but relatively smooth surface. In the last step the selected surface is displayed. We provide examples for the results in real-world dataset as well as in artificially generated datasets. T3 - ZIB-Report - 14-11 KW - Interaction Techniques KW - Volume Rendering KW - Picking KW - Surfaces Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-50266 SN - 1438-0064 ER - TY - GEN A1 - Wiebel, Alexander A1 - Preis, Philipp A1 - Vos, Frans M. A1 - Hege, Hans-Christian T1 - Computation and Application of 3D Strokes on Visible Structures in Direct Volume Rendering N2 - In this paper we describe VisiTrace, a novel technique to draw 3D lines in 3D volume rendered images. It allows to draw strokes in the 2D space of the screen to produce 3D lines that run on top or in the center of structures actually visible in the volume rendering. It can handle structures that only shortly occlude the structure that has been visible at the starting point of the stroke and is able to ignore such structures. For this purpose a shortest path algorithm finding the optimal curve in a specially designed graph data structure is employed. We demonstrate the usefulness of the technique by applying it to MRI data from medicine and engineering, and show how the method can be used to mark or analyze structures in the example data sets, and to automatically obtain good views toward the selected structures. T3 - ZIB-Report - 13-20 KW - DVR KW - interaction Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-18070 SN - 1438-0064 ER -