October 28 – November 2 , 2018, Dagstuhl Seminar 18442

Visualization and Processing of Anisotropy in Imaging, Geometry, and Astronomy


Andrea Fuster (TU Eindhoven, NL)
Evren Özarslan (Linköping University, SE)
Thomas Schultz (Universität Bonn, DE)
Eugene Zhang (Oregon State University – Corvallis, US)

For support, please contact

Annette Beyer for administrative matters

Shida Kunz for scientific matters


List of Participants
Shared Documents
Dagstuhl Seminar Schedule [pdf]


Directional preference or anisotropy is encountered across many disciplines and spatial scales. For example, local anisotropies are imprinted in the cosmic microwave background radiation, the human brain contains elongated nerve fibers, etcetera. Such phenomena lead to physical quantities that take on different values along different directions. Compared to scalar or vector-valued data, it is much more challenging to model, process, and visualize anisotropic quantities.

Scientists encountering anisotropy in specific fields are often unaware of theoretical results and practical tools developed in other fields, while these might be relevant and adaptable to their needs. This Dagstuhl seminar will bring together researchers from three domains in which anisotropy plays an important role:

  • Medical imaging, in which modalities such as diffusion-weighted magnetic resonance imaging (DW-MRI) and quantitative susceptibility mapping are used to probe structure-induced anisotropies, e.g., in the human brain.
  • Geometry processing, where tensor fields have a wide range of applications, such as quadrangular and hexahedral geometry remeshing, street network modeling, geometry synthesis, computational architecture, and path planning for environmental scans.
  • Astronomy, where anisotropies in the cosmic microwave background (CMB) are present in the form of a polarization tensor field. Moreover, in the field of “cosmography”, anisotropies in the cosmic web are linked to the complex patterns traced by galaxies.

Currently, there is little interaction between scientists working in these disciplines. Progress made in one field is usually not transferred to others despite the connections that could make an exchange of ideas very rewarding:

  • Tensor fields play an important role in the three domains, i.e., they all share a common mathematical language.
  • Software tools originally developed for medical imaging have proven useful for 3D visualization of astronomical data.
  • In recent years, differential geometry and topology have made an important contribution in modeling and understanding the structure of the brain from neuroimaging data.
  • The concept of connectivity arises in both astronomy and brain imaging.
  • We expect that advanced techniques for smoothing or feature extraction in tensor-valued images could be transferred to geometry processing.
  • Much insight has been gained on tensor field analysis, especially tensor field topology, by the visualization community. Similar needs have arisen in geometry processing.
This will be the seventh Dagstuhl Seminar in a stimulating and highly interdisciplinary series. Previous seminars had a continuing and strong influence, and led to new collaborations, publications, grant proposals, and international workshops.

  Creative Commons BY 3.0 DE
  Andrea Fuster, Evren Özarslan, Thomas Schultz, and Eugene Zhang

Dagstuhl Seminar Series


  • Computer Graphics / Computer Vision


  • Tensor fields
  • Anisotropy
  • Diffusion-weighted imaging (DWI)
  • Geometry
  • Astronomy

Book exhibition

Books from the participants of the current Seminar 

Book exhibition in the library, ground floor, during the seminar week.


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