Ralf P. Botchen

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One challenge in video processing is to detect actions and events, known or unknown, in video streams dynamically. This paper proposes a visualization solution, where a video stream is depicted as a series of snapshots at a relatively sparse interval, and detected actions are highlighted with continuous abstract illustrations. The combined imagery and(More)
Functional approximation of scattered data is a popular technique for compactly representing various types of datasets in computer graphics, including surface, volume, and vector datasets. Typically, sums of Gaussians or similar radial basis functions are used in the functional approximation and PC graphics hardware is used to quickly evaluate and render(More)
Direct volume rendering has become a powerful, widely-used technique for visualizing 3D volumetric data in many fields. Real-time performance for rendering multiple intersecting volumetric objects requires the speed and flexibility of modern GPUs. This requirement has restricted programming of the necessary shaders to GPU experts only. A visualization(More)
Figure 1: Three different advection schemes applied to a PIV measurement of a fluid flow data set. Left image: Gaussian error diffusion approach. Center image: Cross advection method. Right image: Semi-Lagrangian advection using multi-frequency noise. ABSTRACT In this paper, we present two novel texture-based techniques to visualize uncertainty in(More)
Video visualization is a computation process that extracts meaningful information from original video data sets and conveys the extracted information to users in appropriate visual representations. This paper presents a broad treatment of the subject, following a typical research pipeline involving concept formulation, system development, a path-finding(More)
Traditional volume rendering does not incorporate a number of optical properties that are typically observed for semi-transparent materials, such as glass or water , in the real world. Therefore, we have extended GPU-based raycasting to spectral volume rendering based on the Kubelka-Munk theory for light propagation in parallel col-orant layers of a turbid(More)
We take a new approach to interactive visualization and feature detection of large scalar, vector, and multifield computational fluid dynamics data sets that is also well suited for meshless CFD methods. Radial basis functions (RBFs) are used to procedurally encode both scattered and irregular gridded scalar data sets. The RBF encoding creates a complete,(More)
(a) (b) (c) (d) Figure 1: Example Setup I: Combination of a CTA (Computed Tomography Angiography) dataset and a related MRI (Magnetic Resonance Imaging) dataset of a human head. The MRI dataset provides the skin and brain tissue. It is vertically cut and the two halves are moved away from each other to get insight to the inner structures. The CTA dataset(More)
GPU-assisted multi-field rendering provides a means of generating effective video volume visualization that can convey both the objects in a spatiotemporal domain as well as the motion status of these objects. In this paper, we present a technical framework that enables combined volume and flow visualization of a video to be synthesized using GPU-based(More)
Dye advection is an intuitive and versatile technique to visualize both steady and unsteady flow. Dye can be easily combined with noise-based vector field representations and is an important element in user-centric visual exploration processes. However, texture-based dye advection usually does not consider the convergence and divergence of flow to adapt the(More)