Dr. Stefania Petra

E-Mail: petra (at) math.uni (minus) heidelberg.de

Scientific Interests

My main research lies in Mathematical Imaging and Optimization. In particular, I am interested in Compressed Sensing as well as Variational Inequalities and Complementarity Problems, and how they can be applied in Image Analysis and Tomography.

Teaching

Lecture (WT 14/15) Variational Inequalities: Theory, Applications and Algorithms

PhD Projects

Journal Publications

Phase Transitions and Cosparse Tomographic Recovery of Compound Solid Bodies from Few Projections
A. Denitiu, S. Petra, Cl. Schnörr and Ch. Schnörr, Fundam. Inform., 2014 pdf

Average Case Recovery Analysis of Tomographic Compressive Sensing
S. Petra, and C. Schnörr, LAA, 2014 pdf



Critical Parameter Values and Reconstruction Properties of Discrete Tomography: Application to Experimental Fluid Dynamics
S. Petra, C. Schnörr, and A. Schröder, Fundam. Inform., 2013 pdf arXiv



A class of quasi-variational inequalities for adaptive image denoising and decomposition
F. Lenzen, F. Becker, J. Lellmann, S. Petra, and C. Schnörr, Comput. Optim. Appl., 2013 pdf


Variational Adaptive Correlation Method for Particle Image Velocimetry
F. Becker, B. Wieneke, S. Petra, A. Schröder, and C. Schnörr, IEEE Trans. Image Proc., 2012 pdf


A General Extending and Constraining Procedure for Linear Iterative Methods
A. Nicola, S. Petra, C. Popa, and C. Schnörr, Int. J. Comp. Math., 2011 pdf




TomoPIV meets Compressed Sensing
S. Petra, and C. Schnörr, Pure Math. Appl., 2009 pdf




Projected Filter Trust Region Methods for a Semismooth Least Squares Formulation of Mixed Complementarity Problems
C. Kanzow, and S. Petra, Optim. Meth. and Soft., 2007 pdf

On a Semismooth Least Squares Formulation of Complementarity Problems with Gap Reduction
C. Kanzow, and S. Petra, Optim. Meth. and Soft., 2004 pdf

Preprints

Average Case Recovery Analysis
of Tomographic Compressive Sensing

S. Petra, and C. Schnörr, submitted to LAA, 2012 pdf arXiv





An Inexact Semismooth Least Squares Method for Large-Scale Complementarity Problems
C. Kanzow and S. Petra, 2004 pdf

Software

LMMCP - A Levenberg-Marquardt-type MATLAB Solver for Mixed Complementarity Problems
C. Kanzow and S. Petra, 2005 pdf

Conference Publications

Adaptive Dictionary-Based Spatio-Temporal Flow Estimation for Echo PIV
E. Bodnariuc, A. Gurung, S. Petra, and C. Schnörr, EMMCVPR, 2015 pdf

An Entropic Perturbation Approach to TV-Minimization for Limited-Data Tomography
A. Denitiu, S. Petra, Cl. Schnörr and Ch. Schnörr, DGCI, 2014 pdf



Reconstruction Properties of Sensing Matrices in Tomographic Particle Imaging Velocimetry
S. Petra, A. Schröder and C. Schnörr, FVR, 2011 pdf




Variational Image Denoising with Adaptive Constraint Sets
F. Lenzen, F. Becker, and J. Lellmann, S. Petra, and C. Schnörr, SSVM, 2011 pdf





Sparse Templates-Based Shape Representation for Image Segmentation
S. Petra, D. Breitenreicher, J. Lellmann and C. Schnörr, SPARS, 2011 pdf


TomoPIV meets Compressed Sensing
S. Petra, and C. Schnörr, ICNAAM, 2010 pdf



Recasting Tomo-PIV Reconstruction as Constrained and L1-Regularized Non-Linear Least Squares Problem
S. Gesemann, D. Schanz, A. Schröder, S. Petra, and C. Schnörr, LaserTECH, 2010 pdf

On Sparsity Maximization in Tomographic Particle Image Reconstruction
S. Petra, A. Schröder, B. Wieneke, and C. Schnörr, WMM, 2008 pdf





Enhancing Sparsity by Constraining Strategies: Constrained SIRT versus Spectral Projected Gradient Methods
S. Petra, C. Popa, and C. Schnörr, WMM, 2008 pdf





Tomographic Image Reconstruction in Experimental Fluid Dynamics: Synopsis and Problems
S. Petra, C. Schnörr, A. Schröder, and B. Wieneke, WMM, 2007 pdf

Book Chapter

Optical Flow
F. Becker, S. Petra, and C. Schnörr, Handbook of Mathematical Methods in Imaging, Springer, 2014 pdf


3D Tomography from Few Projections in Experimental Fluid Mechanics
S. Petra, A. Schröder, and C. Schnörr, Imaging Measurement Methods for Flow Analysis, Springer, 2009 pdf

Short CV

Jun 2001 B.Sc. in Mathematics and Computer Science at Cluj-Napoca University, Romania
Jun 2003 M.Sc. in Mathematics at Cluj-Napoca University
Jul 2006 Ph.D. in Mathematics at University Würzburg
Feb 2007 - Dec 2012 postdoctoral research fellow with IPA at Heidelberg University
(former CVGPR Group, University Mannheim)
since 2013 junior research group leader in the Faculty of Mathematics and Informatics at the University of Heidelberg, enrolled in the Margarete von Wrangell postdoctoral lecture qualification program

Contact

Stefania Petra
ipa - Image and Pattern Analysis Group
Department of Mathematics and Computer Science
University of Heidelberg
Speyerer Str. 6, room H 2.22
69115 Heidelberg, Germany

Tel: (+49) 6221 - 54 5288
Fax: (+49) 6221 - 54 5276