Fakultät Informatik

Freeform Image

 Thomas Schiwietz,  Joachim Georgii, Rüdiger Westermann

Computer Graphics and Visualization Group, Technische Universität München, Germany


In this paper we present a technique for image deformation in which the user is given flexible control over what kind of deformation to perform. Freeform image extends available image deformation techniques in that it provides a palette of intuitive tools including interactive object segmentation, stiffness editing and force-based controls to achieve both a natural look and realistic animations of deforming parts. The model underlying our approach is physics-based and it is amenable to a variety of different kinds of image manipulations ranging from as-rigid-as-possible to fully elastic deformations. We have developed a multigrid solver for quadrangular finite elements, which achieves real-time performance for high resolution pixel grids. On recent CPUs this solver can handle about 16K co-rotated finite elements at roughly 60 ms.

Modified material laws: Images (b) and (c) show the difference between Hooke’s law and the rigid law if the castle is stretched vertically. Images (d) and (e) demonstrate the effects of reducing the amount of shearing (d) and rotation (e) while the castle is dragged to the right.

Associated publications

Freeform Image
T. Schiwietz, J. Georgii, R. Westermann, Pacific Graphics 2007 [Bibtex]


Accompanying video of the paper [13 MB WMV]



- In collaboration with partners from industry, we have a number of thesis topics available in the area of point-based rendering, geo-localization using public data, scene fusion from different viewpoints. If you are interested, please contact  westermann(at)tum.de


- One PhD position on   Turbulence Visualization is available at the Computer Graphics & Visualization group.