Since February 1, 2015:
I am with KTH Stockholm, Sweden,
to establish the new Chair of Visualization
in the School of Computer Science and Communication.
new address

D. Günther, A. Jacobson, J. Reininghaus, H.-P. Seidel, O. Sorkine-Hornung, T. Weinkauf
Fast and Memory-Efficient Topological Denoising of 2D and 3D Scalar Fields
IEEE Transactions on Visualization and Computer Graphics (Proc. IEEE VIS) 20(12), December 2014

We present a topological denoising technique based on a global energy optimization suitable for large 2D data and medium-sized 3D data. It leverages a novel domain decomposition approach and an iterative refinement of the solution.

paper  •  image gallery

G. Palmas, M. Bachynskyi, A. Oulasvirta, H.-P. Seidel, T. Weinkauf
MovExp: A Versatile Visualization Tool for Human-Computer Interaction Studies with 3D Performance and Biomechanical Data
IEEE Transactions on Visualization and Computer Graphics (Proc. IEEE VIS) 20(12), December 2014

Recently, a novel cost-efficient method for estimating physical ergonomics and performance has been introduced to HCI. It is based on optical motion capture and biomechanical simulation.

We present MovExp, a versatile visualization tool that supports the evaluation of user interfaces. In particular, it can be easily adapted by the HCI experts to include the physical setup that is being evaluated, and visualize the data on top of it. Furthermore, it provides a variety of visual encodings to communicate muscular loads, movement directions, and other specifics of HCI studies that employ motion capture and biomechanical simulation.

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H. Saikia, H.-P. Seidel, T. Weinkauf
Extended Branch Decomposition Graphs: Structural Comparison of Scalar Data
Computer Graphics Forum (Proc. EuroVis) 33(3), June 2014

Structures repeat in both nature and engineering, with some degree of variation.

We present a method to find repeating topological structures in scalar data sets. In a redundancy-free manner, we compare all subtrees of two merge trees against each other. This is based on a novel data structure called the extended branch decomposition graph. We provide highly efficient algorithms for computing and comparing them.

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G. Palmas, M. Bachynskyi, A. Oulasvirta, H.-P. Seidel, T. Weinkauf
An Edge-Bundling Layout for Interactive Parallel Coordinates
Proc. IEEE PacificVis, Yokohama, Japan, March 4 - 7, 2014

Parallel Coordinates is an often used visualization method for multidimensional data sets. Its main challenges for large data sets are visual clutter and overplotting which hamper the recognition of patterns in the data.

We present an edge-bundling method using density-based clustering for each dimension. This reduces clutter and provides a faster overview of clusters and trends. Moreover, it allows rendering the clustered lines using polygons, decreasing rendering time remarkably. In addition, we design interactions to support multidimensional clustering with this method.

paper  •  image gallery  •  videos