TY - GEN A1 - Stalling, Detlev A1 - Zöckler, Malte A1 - Hege, Hans-Christian T1 - Fast Display of Illuminated Field Lines N2 - A new technique for interactive vector field visualization using large numbers of properly illuminated field lines is presented. Taking into account ambient, diffuse, and specular reflection terms as well as transparency and depth cueing, we employ a realistic shading model which significantly increases quality and realism of the resulting images. While many graphics workstations offer hardware support for illuminating surface primitives, usually no means for an accurate shading of line primitives are provided. However, we show that proper illumination of lines can be implemented by exploiting the texture mapping capabilities of modern graphics hardware. In this way high rendering performance with interactive frame rates can be achieved. We apply the technique to render large numbers of integral curves of a vector field. The impression of the resulting images can be further improved by a number of visual enhancements, like transparency and depth-cueing. We also describe methods for controlling the distribution of field lines in space. These methods enable us to use illuminated field lines for interactive exploration of vector fields. T3 - ZIB-Report - SC-96-58 Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-2686 ER - TY - GEN A1 - Battke, Henrik A1 - Stalling, Detlev A1 - Hege, Hans-Christian T1 - Fast Line Integral Convolution for Arbitrary Surfaces in 3D N2 - We describe an extension of the line integral convolution method (LIC) for imaging of vector fields on arbitrary surfaces in 3D space. Previous approaches were limited to curvilinear surfaces, i.e.~surfaces which can be parametrized globally using 2D-coordinates. By contrast our method also handles the case of general, possibly multiply connected surfaces. The method works by tesselating a given surface with triangles. For each triangle local euclidean coordinates are defined and a local LIC texture is computed. No scaling or distortion is involved when mapping the texture onto the surface. The characteristic length of the texture remains constant. In order to exploit the texture hardware of modern graphics computers we have developed a tiling strategy for arranging a large number of triangular texture pieces within a single rectangular texture image. In this way texture memory is utilized optimally and even large textured surfaces can be explored interactively. T3 - ZIB-Report - SC-96-59 Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-2690 ER - TY - GEN A1 - Stalling, Detlev A1 - Hege, Hans-Christian T1 - Fast and Resolution Independent Line Integral Convolution N2 - Line Integral Convolution (LIC) is a powerful technique for generating striking images and animations from vector data. Introduced in 1993, the method has rapidly found many application areas, ranging from computer arts to scientific visualization. Based upon locally filtering an input texture along a curved stream line segment in a vector field, it is able to depict directional information at high spatial resolutions. We present a new method for computing LIC images, which minimizes the total number of stream lines to be computed and thereby reduces computational costs by an order of magnitude compared to the original algorithm. Our methods utilizes fast, error-controlled numerical integrators. Decoupling the characteristic lengths in vector field grid, input texture and output image, it allows to compute filtered images at arbitrary resolution. This feature is of great significance in computer animation as well as in scientific visualization, where it can be used to explore vector data by smoothly enlarging structure of details. We also present methods for improved texture animation, employing constant filter kernels only. To obtain an optimal motion effect, spatial decay of correlation between intensities of distant pixels in the output image has to be controlled. This is achieved by blending different phase shifted box filter animations and by adaptively rescaling the contrast of the output frames. T3 - ZIB-Report - SC-94-37 Y1 - 1995 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-1653 ER - TY - GEN A1 - Stalling, Detlev A1 - Zöckler, Malte A1 - Sander, Oliver A1 - Hege, Hans-Christian T1 - Weighted Labels for 3D Image Segmentation N2 - Segmentation tools in medical imaging are either based on editing geometric curves or on the assignment of region labels to image voxels. While the first approach is well suited to describe smooth contours at subvoxel accuracy, the second approach is conceptually more simple and guarantees a unique classification of image areas. However, contours extracted from labeled images typically exhibit strong staircase artifacts and are not well suited to represent smooth tissue boundaries. In this paper we describe how this drawback can be circumvented by supplementing region labels with additional weights. We integrated our approach into an interactive segmentation system providing a well-defined set of manual and semi-automatic editing tools. All tools update both region labels as well as the corresponding weights simultaneously, thus allowing one to define segmentation results at high resolution. We applied our techniques to generate 3D polygonal models of anatomical structures. T3 - ZIB-Report - SC-98-39 KW - image processing KW - segmentation Y1 - 1998 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-3828 ER - TY - THES A1 - Stalling, Detlev T1 - Fast Texture-Based Algorithms for Vector Field Visualization N2 - In this thesis we develop new methods for visualizing vector fields which specifically address three design goals: accuracy, performance, and cognition. Our methods will be general-purpose and can be applied to arbitrary vector fields in two- and three-dimensional space. The methodology behind our approach is {\em texture-based visualization}. Texture-based visualization methods imitate techniques known from experimental flow visualization, namely, the observation of randomly dispersed particles or dye injection patterns. Instead of depicting individual lines or symbols, a contiguous high-resolution image or texture is generated. This texture clearly reveals the directional structure of the field. In this way intuitive insight can be obtained and even small details of the field become visible. However, it remains unclear what kind of textures are best suited for our purpose. How do we generate them? Can we apply these methods in three-dimensional space? In particular, we focus on a technique known as {\em line integral convolution} or LIC. This method turns out to be quite versatile and well-suited for visualizing many interesting vector fields. LIC images display the integral curves or field lines of a vector field at high spatial resolution. Although conceptually quite simple, line integral convolution implies a number of interesting mathematical and algorithmic questions. T3 - ZIB-Report - SC-98-40 KW - computer graphics KW - line integral convolution KW - stream surfaces Y1 - 1998 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-3838 ER - TY - GEN A1 - Stalling, Detlev A1 - Seebass, Martin A1 - Zachow, Stefan T1 - Mehrschichtige Oberflächenmodelle zur computergestützten Planung in der Chirurgie N2 - Polygonale Schädelmodelle bilden ein wichtiges Hilfsmittel für computergestützte Planungen im Bereich der plastischen Chirurgie. Wir beschreiben, wie derartige Modelle automatisch aus hochaufgelösten CT-Datensätzen erzeugt werden können. Durch einen lokal steuerbaren Simplifizierungsalgorithmus werden die Modelle so weit vereinfacht, daß auch auf kleineren Graphikcomputern interaktives Arbeiten möglich wird. Die Verwendung eines speziellen Transparenzmodells ermöglicht den ungehinderten Blick auf die bei der Planung relevanten Knochenstrukturen und läßt den Benutzer zugleich die Kopfumrisse des Patienten erkennen. T3 - ZIB-Report - TR-98-05 KW - Isoflächen KW - Simplifizierung KW - Transparenzen Y1 - 1998 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-5661 ER - TY - GEN A1 - Hege, Hans-Christian A1 - Höllerer, Tobias A1 - Stalling, Detlev T1 - Volume Rendering - Mathematicals Models and Algorithmic Aspects. N2 - In this paper various algorithms for rendering gaseous phenomena are reviewed. In computer graphics such algorithms are used to model natural scenes containing clouds, fog, flames and so on. On the other hand it has become an important technique in scientific visualization to display three dimensional scalar datasets as cloudy objects. Our emphasis is on this latter subject of so-called {\em direct volume rendering}. All algorithms will be discussed within the framework of linear transport theory. The equation of transfer is derived. This equation is suitable to describe the radiation field in a participating medium where absorption, emission, and scattering of light can occur. Almost all volume rendering algorithms can be shown to solve special cases of the equation of transfer. Related problems like the mapping from data values to model parameters or possible parallelization strategies will be discussed as well. T3 - ZIB-Report - TR-93-07 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-4994 ER - TY - GEN A1 - Zöckler, Malte A1 - Stalling, Detlev A1 - Hege, Hans-Christian T1 - Fast and Intuitive Generation of Geometric Shape Transitions N2 - We describe a novel method for continuously transforming two triangulated models of arbitrary topology into each other. Equal global topology for both objects is assumed, extensions for genus changes during metamorphosis are provided. The proposed method addresses the major challenge in 3D metamorphosis, namely specifying the morphing process intuitively, with minimal user interaction and sufficient detail. Corresponding regions and point features are interactively identified. These regions are parametrized automatically and consistently, providing a basis for smooth interpolation. Utilizing suitable 3D interaction techniques a simple and intuitive control over the whole morphing process is offered. T3 - ZIB-Report - SC-99-33 KW - morphing KW - surface parametrization KW - shape transition Y1 - 1999 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-4219 ER - TY - GEN A1 - Hege, Hans-Christian A1 - Stalling, Detlev T1 - Fast LIC with Higher Order Filter Kernels N2 - Line integral convolution (LIC) has become a well-known and popular method for visualizing vector fields. The method works by convolving a random input texture along the integral curves of the vector field. In order to accelerate image synthesis significantly, an efficient algorithm has been proposed that utilizes pixel coherence in field line direction. This algorithm, called ``fast LIC'', originally was restricted to simple box-type filter kernels. Here we describe a generalization of fast LIC for piecewise polynomial filter kernels. Expanding the filter kernels in terms of truncated power functions allows us to exploit a certain convolution theorem. The convolution integral is expressed as a linear combination of repeated integrals (or repeated sums in the discrete case). Compared to the original algorithm the additional expense for using higher order filter kernels, e.g.\ of B-spline type, is very low. Such filter kernels produce smoother, less noisier results than a box filter. This is evident from visual investigation, as well as from analysis of pixel correlations. Thus, our method represents a useful extension of the fast LIC algorithm for the creation of high-quality LIC images. T3 - ZIB-Report - SC-97-74 Y1 - 1998 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-3439 ER - TY - CHAP A1 - Beck, Rudolf A1 - Deuflhard, Peter A1 - Hege, Hans-Christian A1 - Seebass, Martin A1 - Stalling, Detlev ED - Hege, Hans-Christian ED - Polthier, Konrad T1 - Numerical Algorithms and Visualization in Medical Treament Planning T2 - Visualization and Mathematics Y1 - 1997 SP - 303 EP - 328 PB - Springer-Verlag ER - TY - CHAP A1 - Deuflhard, Peter A1 - Seebass, Martin A1 - Stalling, Detlev A1 - Beck, Rudolf A1 - Hege, Hans-Christian ED - Sydow, Achim T1 - Hyperthermia Treatment Planning in Clinical Cancer Therapy:Modelling, Simulation, and Visualization T2 - Computational Physics, Chemistry and Biology Y1 - 1997 VL - 3 PB - Wissenschaft und Technik Verlag CY - Plenary keynote talk, 15th IMACS World Congress 1997 on Scientific Computation, Modelling and Applied Mathematics ER - TY - JOUR A1 - Goubergrits, Leonid A1 - Kertzscher, Ulrich A1 - Affeld, Klaus A1 - Petz, Christoph A1 - Stalling, Detlev T1 - Numerical Dye Washout Method as a Tool for Characterizing the Heart Valve Flow JF - ASAIO Journal Y1 - 2008 U6 - https://doi.org/10.1097/MAT.0b013e31815c5e38 VL - 54(1) SP - 50 EP - 57 ER - TY - CHAP A1 - Dercksen, Vincent J. A1 - Brüß, Cornelia A1 - Stalling, Detlev A1 - Gubatz, Sabine A1 - Seiffert, Udo A1 - Hege, Hans-Christian T1 - Towards automatic generation of 3D models of biological objects based on serial sections T2 - Visualization in Medicine and Life Sciences Y1 - 2008 U6 - https://doi.org/10.1007/978-3-540-72630-2 SP - 3 EP - 25 PB - Springer-Verlag Berlin Heidelberg ER - TY - GEN A1 - Stalling, Detlev A1 - Westerhoff, Malte A1 - Hege, Hans-Christian ED - Hansen, Charles ED - Johnson, Christopher T1 - Amira: A highly interactive system for visual data analysis T2 - The Visualization Handbook Y1 - 2005 U6 - https://doi.org/10.1016/B978-012387582-2/50040-X SP - 749 EP - 767 PB - Elsevier ER - TY - JOUR A1 - Goubergrits, Leonid A1 - Timmel, Tobias A1 - Affeld, Klaus A1 - Petz, Christoph A1 - Stalling, Detlev A1 - Hege, Hans-Christian T1 - Characterization of an artificial valve flow using the numerical dye washout visualization technique JF - Artificial Organs Y1 - 2006 VL - 30(8) SP - 642 EP - 650 ER - TY - GEN A1 - Stalling, Detlev A1 - Seebass, Martin A1 - Zöckler, Malte A1 - Hege, Hans-Christian T1 - Hyperthermia Treatment Planning with HyperPlan - User's Manual N2 - HyperPlan is a software system for performing 3D-simulations and treatment planning in regional hyperthermia. It allows the user to understand the complex effects of electromagnetic wave propagation and heat transport inside a patient's body. Optimized power amplitudes and phase settings can be calculated for the BSD radiowave applicators Sigma 60 and Sigma 2000 (eye-applicator). HyperPlan is built on top of the modular, object-oriented visualization system Amira. This system already contains powerful algorithms for image processing, geometric modelling and 3D graphics display. HyperPlan provides a number of hyperthermia-specific modules, allowing the user to create 3D tetrahedral patient models suitable for treatment planning. In addition, all numerical simulation modules required for hyperthermia simulation are part of HyperPlan. This guide provides a step-by-step introduction to hyperthermia planning using HyperPlan. It also describes the usage of the underlying visualization system Amira. T3 - ZIB-Report - 00-27 KW - image segmentation KW - grid generation KW - visualization KW - therapy planning Y1 - 2000 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-5957 ER - TY - GEN A1 - Zöckler, Malte A1 - Rein, Karlheinz A1 - Brandt, Robert A1 - Stalling, Detlev A1 - Hege, Hans-Christian T1 - Creating Virtual Insect Brains with Amira N2 - By combining techniques of preparation, histology, confocal microscopy, data visualization and data processing, we have created and recently published a standard brain model for drosophila and honey bee brains. This report describes the algorithms and implementation of the corresponding software modules. At the same time it serves as a user's guide for scientist who want to reproduce the results for differerent species or mutants. T3 - ZIB-Report - 01-32 KW - visualization KW - anatomical atlas Y1 - 2001 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-6589 ER -