Colas Schretter
Bio
I completed the M.Sc. degree in computer science with great honors in 2004 and received an additional Master of advanced studies in 2006 from the Université libre de Bruxelles, Belgium. I moved to Germany in February 2007 for a scientist position with Philips Research, Aachen. Meanwhile, I earned a Marie Curie EST fellowship for my doctoral thesis, endorsed with magna cum laude by the Otto-von-Guericke University. I was awarded a Marie Curie ERG grant from the European Commission for my postdoctoral project with the RWTH Aachen University and was visiting researcher at the Politecnico di Milano, Italy. Since July 2012, I'm a M+Vision fellow at MIT in Cambridge, USA and work in collaboration with the MGH hospital in Boston.
Projects
My recent work combines emergent machine learning techniques with classical geometrical algorithms for solving large density estimation problems with multi-resolution (scale-space) semi-parametric Gaussian mixture models. In particular, I'm applying novel online expectation-maximization methods for statistical image reconstruction in time-of-flight positron emission tomography (TOF-PET) and for fast evaluations of smoothed visibility queries in computer rendering with image-based lighting. This project is sponsored by the Framework Programme 7 of the European Commission under contract PERG06-GA-2009-256519.
Links
Click on the images to open linked websites.
Journal papers
Colas Schretter and Harald Niederreiter,
A Direct Inversion Method for Non-Uniform Quasi-Random Point Sequences,
Monte Carlo Methods and Applications, vol. 19, no. 1, pp. 1–9, 2013.
Link
Colas Schretter, Leif Kobbelt and Paul-Olivier Dehaye,
Golden Ratio Sequences for Low-Discrepancy Sampling,
Journal of Graphics Tools, vol. 16, no. 2, pp. 95–104, 2012.
Link
Colas Schretter, Georg Rose and Matthias Bertram,
Image-Based Iterative Compensation of Motion Artifacts in Computed Tomography,
Medical Physics, vol. 36, no. 11, pp. 5323–5330, 2009.
Link
Colas Schretter,
Event-by-Event Image Reconstruction From List-Mode PET Data,
IEEE Transactions on Image Processing, vol. 8, no. 1, pp. 117–124, 2009.
Link
Patrick E. Meyer, Colas Schretter and Gianluca Bontempi,
Information-Theoretic Feature Selection in Microarray Data Using Variable Complementarity,
IEEE Journal of Selected Topics in Signal Processing, vol. 2, no. 3, pp. 261–274, 2008.
Link
Colas Schretter,
A Fast Tube of Response Ray-Tracer,
Medical Physics, vol. 33, no. 12, pp. 4744–4748, 2006.
Link
Colas Schretter and Michel C. Milinkovitch,
OligoFaktory: A Visual Tool for Interactive Oligonucleotide Design,
Bioinformatics, vol. 22, no. 1, pp. 115–116, 2006.
Paper
Colas Schretter,
A Brush Tool for Interactive Texture Synthesis,
ICGST International Journal on Graphics, Vision and Image Processing, vol. 6, no. 5, pp. 55–60, 2005.
Link
Conference Papers
Colas Schretter, Jianyong Sun and Leif Kobbelt,
Online Estimation of B-Spline Mixture Models From TOF-PET List-Mode Data,
Proc. of the 11th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, Potsdam, Germany, July 11-15, pp. 274–277, 2011.
Paper
Se Young Chun, Colas Schretter and Jeffrey A. Fessler,
Sufficient Condition for Local Invertibility of Spatio-Temporal 4D B-Spline Deformations,
Proc. of the 7th IEEE International Symposium on Biomedical Imaging, Rotterdam, The Netherlands, April 14-17, pp. 1221–1224, 2010.
Link, Poster
Colas Schretter, Fabian Pilatus, Georg Rose, Til Aach and Matthias Bertram,
Optical Flow Motion Estimation for Approximate Motion Compensation in Cone-Beam CT,
Proc. of the 10th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, Beijing, China, September 5-10, pp. 327–330, 2009.
Paper
Colas Schretter, Christoph Neukirchen, Georg Rose and Matthias Bertram,
Optimal Pre-Filtering for Linear Interpolation in Computed Tomography,
Proc. of the 2nd Workshop on High-Performance Image Reconstruction, Beijing, China, September 6, pp. 29–32, 2009.
Paper
Colas Schretter,
Online PET Reconstruction From List-Mode Data,
Proc. of the 10th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, Beijing, China, September 5-10, pp. 195–198, 2009.
Paper, Poster
Colas Schretter, Christoph Neukirchen, Georg Rose and Matthias Bertram,
Image-Based Iterative Compensation of Motion Artifacts in Computed Tomography,
SPIE Medical Imaging, Lake Buena Vista, USA, February 7-12, vol. 7258, pp. 1W–8, 2009.
Link
Colas Schretter, Christoph Neukirchen, Georg Rose and Matthias Bertram,
Local Correction of Non-Periodic Motion in Computed Tomography,
SPIE Medical Imaging, Lake Buena Vista, USA, February 7-12, vol. 7258, pp. 2M–12, 2009.
Link, Poster
Colas Schretter, Christoph Neukirchen, Matthias Bertram and Georg Rose,
Correction of Some Time-Dependent Deformations in Parallel-Beam Computed Tomography,
Proc. of the 5th IEEE International Symposium on Biomedical Imaging, Paris, France, May 14-17, pp. 764–767, 2008.
Link
Ralph Brinks, Colas Schretter and Carsten Meyer,
Comparison of Maximum-Likelihood List-Mode Reconstruction Algorithms in PET,
Proc. of the IEEE Nuclear Science Symposium and Medical Imaging Conference, San Diego, USA, October 29 - November 4, vol. M11-389, pp. 2801–2803, 2006.
Link
Invited Lectures
Colas Schretter,
Séquences et ensembles quasi-aléatoires,
Brussels Summer School of Mathematics (BSSM), Brussels, Belgium, August 1-7, invited instructor, 2013.
Colas Schretter,
Hierarchical B-Spline Mixture Models for TOF-PET Image Reconstruction,
M+Vision Open-House, Madrid, Spain, July 19-20, 2012.
Colas Schretter and Leif Kobbelt,
Golden Ratio Sequences for Low-Discrepancy Sampling,
HiGraphics, Hirschegg, Austria, March 27-31, 2011.
Poster Presentations
Colas Schretter, Jason N. Hill and Martha L. Gray,
Wake-Up to Bruxism: Sleep Monitoring and Personalized Audio Feedback on your Smartphone,
MIT Future of Health and Wellness Conference, Cambridge, February 6-7, 2013.
MIT Sloan BioInnovations Conference, Cambridge, February 22, 2013.
Poster
Alfonso A. Isola, Colas Schretter, Michael Grass, Matthias Bertram, Georg Rose and Wiro J. Niessen,
Compensation of Periodic Cardiac Motion and Non-Periodic Abdominal Motion in Cone-Beam CT,
Marie Curie Monitoring Mission, Alexander von Humboldt Foundation, Bonn, Germany, January 29-30, 2009.
Poster
Colas Schretter,
Improving Image Quality in Computed Tomography by Motion Estimation and Compensation,
8th IEEE EMBS International Summer School on Biomedical Imaging, Berder, France, June 20-28, 2008.
Colas Schretter, Laurent Gatto and Michel C. Milinkovitch,
OligoFaktory: A Web Portal for Interactive Oligonucleotide Design,
First BENELUX Bioinformatics Conference, Ghent, Belgium, April 14-15, 2005.
Poster
Technical notes
Laurent Gatto and Colas Schretter,
Designing Primer Pairs and Oligos with OligoFaktorySE,
EMBnet news, vol. 15, no. 3, pp. 22–24, 2009.
Link
Colas Schretter,
Computing Random Points on Sphere,
Boost C++ Ticket 1059, June, 2007.
Link
Colas Schretter,
Discover OligoFaktory Standalone Edition,
EMBnet news, vol. 11, no. 4, pp. 24–25, 2005.
Link
Colas Schretter and Laurent Gatto,
A Tiny Queuing System for Blast Servers,
December, 2005.
Link
Colas Schretter and Michel C. Milinkovitch,
Automated Long Oligo Design on Consensus Regions of Similar Genomes,
Technical Report UEG, IBMM, ULB, 2005.
Colas Schretter and Michel C. Milinkovitch,
Oligonucleotide Design by Multilevel Optimization,
Technical Report UEG, IBMM, ULB, 2005.
Dissertations
Colas Schretter,
Correction of Non-Periodic Motion in Computed Tomography,
Doctoral thesis, Otto-von-Guericke University, Magdeburg, Germany, April, 2010.
Link
Colas Schretter,
New Algorithms for Image Reconstruction From Emission Tomography List-Mode Data,
DEA thesis, Université libre de Bruxelles, Brussels, Belgium, September, 2006.
Colas Schretter,
Efficient N-Body Algorithms for Astrophysical Simulations,
Master thesis, Université libre de Bruxelles, Brussels, Belgium, June, 2003.
Patents
Colas Schretter, Matthias Bertram and Christoph Neukirchen,
Method and Apparatus For Large Field of View Imaging and Detection and Compensation of Motion Artifacts,
US 30961/04024, January, 2009.
Link
Peter Forthmann, Thomas Koehler, Udo Van Stevendaal, Matthias Bertram, Steffen Hohmann and Colas Schretter,
Method and Apparatus to Improve CT Image Acquisition Using Displaced Geometry,
US 30961/04021, September, 2008.
Link