Image of Me

Stefan Sommer

PostDoc in the Image Group, Department of Computer Science
Email: sommer@diku.dk
Office: 04.0.04, Building E, HCØ
See also: www.nefan.dk




Research

Shape modeling, modelling using manifolds, statistics on manifolds, computations on manifolds, bicycle chain shape models and diffeomorphisms.

Projects

Member of CSGB.
Part of the Learning Imaging Biomarkers (LImB) project.

Software

See my github page for various software projects including the segframe prototype code for image registration with the kernel bundle framework and higher-order momentum distributions.
The project smanifold contains the manifold and exact PGA code used in the papers Optimization over Geodesics for Exact Principal Geodesic Analysis (preprint) and Manifold Valued Statistics, Exact Principal Geodesic Analysis and the Effect of Linear Approximations .

Publications

Image Analysis / Deformation Modeling / Statistics on Manifolds

  • Stefan Sommer, François Lauze, and Mads Nielsen:
    Optimization over Geodesics for Exact Principal Geodesic Analysis (pdf)
    To appear in Advances in Computational Mathematics, in press. Preprint available at (arxiv.org)
  • Stefan Sommer:
    Horizontal Dimensionality Reduction and Iterated Frame Bundle Development (pdf)
    Geometric Science of Information (GSI) 2013.
  • Stefan Sommer, François Lauze, Mads Nielsen, and Xavier Pennec:
    Sparse Multi-Scale Diffeomorphic Registration: the Kernel Bundle Framework (pdf)
    Journal of Mathematical Imaging and Vision, 2013.
  • Stefan Sommer, Mads Nielsen, Sune Darkner, and Xavier Pennec:
    Higher-Order Momentum Distributions and Locally Affine LDDMM Registration
    SIAM Journal on Imaging Sciences, 2013. Preprint at (arxiv.org)
  • Stefan Sommer, Mads Nielsen, and Xavier Pennec:
    Sparsity and Scale: Compact Representations of Deformation for Diffeomorphic Registration (pdf)
    MMBIA workshop at WACV 2012, Breckenridge, Colorado, 2012.
  • Søren Hauberg, Stefan Sommer, and Kim Steenstrup Pedersen:
    Natural Metrics and Least-Committed Priors for Articulated Tracking (pdf)
    Accepted for publication in Elsevier Journal on Image and Vision Computing.
  • Stefan Sommer:
    Accelerating Multi-Scale Flows for LDDKBM Diffeomorphic Registration (pdf)
    GPUCV workshop at ICCV 2011, Barcelona, Spain, 2011.
  • Stefan Sommer, François Lauze, Søren Hauberg, and Mads Nielsen:
    Kernel Bundle EPDiff: Evolution Equations for Multi-Scale Diffeomorphic Image Registration (pdf)
    Scale Space and Variational Methods in Computer Vision (SSVM) 2011, Ein-Gedi, Israel, 2011.
    The original publication is available at www.springerlink.com
  • Stefan Sommer, Mads Nielsen, François Lauze, and Xavier Pennec:
    A Multi-Scale Kernel Bundle for LDDMM: Towards Sparse Deformation Description Across Space and Scales (pdf)
    Information Processing in Medical Imaging (IPMI) 2011, Irsee, Germany, 2011.
    The original publication is available at www.springerlink.com
  • Stefan Sommer, François Lauze, Søren Hauberg, and Mads Nielsen:
    Manifold Valued Statistics, Exact Principal Geodesic Analysis and the Effect of Linear Approximations (pdf)
    European Conference on Computer Vision (ECCV) 2010, Heraklion, Greece, 2010.
    The original publication is available at www.springerlink.com
  • Søren Hauberg, Stefan Sommer, and Kim Steenstrup Pedersen:
    Gaussian-like Spatial Priors for Articulated Tracking (pdf)
    European Conference on Computer Vision (ECCV) 2010, Heraklion, Greece, 2010.
    The original publication is available at www.springerlink.com
  • Aditya Tatu, François Lauze, Stefan Sommer and Mads Nielsen:
    On Restricting Planar Curve Evolution to Finite Dimensional Implicit Subspaces with Non-Euclidean Metric (pdf)
    Journal of Mathematical Imaging and Vision, Springer 2010
    The original publication is available at www.springerlink.com
  • Stefan Sommer, Aditya Tatu, Chen Chen, Dan R. Jørgensen, Marleen de Bruijne, Marco Loog, Mads Nielsen, and François Lauze:
    Bicycle Chain Shape Models (pdf) (ieee)
    Mathematical Methods in Biomedical Image Analysis (MMBIA) at CVPR 2009, Miami Beach, Florida, 2009.

Power System Analysis

  • Stefan Sommer and Hjörtur Jóhannsson:
    Real-Time Thevenin Impedance Computation (pdf)
    IEEE PES ISGT 2013, Washington D.C., USA, 2013
  • Tilman Weckesser, Hjörtur Jóhannsson, Stefan Sommer, and Jacob Østergaard:
    Investigation of the Adaptability of Transient Stability Assessment Methods to Real-Time Operation (pdf)
    IEEE PES ISGT Europe 2012, Berlin, Germany, 2012.

Preprints and Submitted Papers

Theses

  • PhD Thesis:
    Anatomy in Curved Space
    Non-linear Modeling of Deformation and Shape for Medical Imaging     (pdf)
    Department of Computer Science, University of Copenhagen, 2011.
  • Master's Thesis:
    The Rate of Change of Width under Ricci Flow.
    A Part of the Proof of the Poincaré Conjecture.     (pdf)
    Department of Mathematical Sciences, University of Copenhagen, 2008.


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