Et profilbilde

Professor
Engan, Kjersti { "honorific-suffix": "Professor", "fn": "Engan, Kjersti", "tel": "Telephone: +47 5183 2008", "email": "kjersti.engan@uis.no" }

Faculty Faculty of Science and Technology
Department Department of Electrical and Computer Engineering
Room KE E-423E

Courses taught

Research areas

My research interests are in signal and image processing, and especially:

- Dictionary learning for sparse signal and image representations.  These dictionaries can be used for different applications such as compression, denoising and texture classification etc.

- Biomedical image processing.  We have ongoing research collaboration with several groups at Stavanger University Hospital (SUS) on analysis and classification of magnetic resonance (MR) images of heart on infarct patients and MR images of brain on patients with dementia.

Selected publications

Journal Publications:

  1. K. Engan, S. O. Aase, and J. H. Husøy, ``Multi-frame compression: Theory and design,'' Signal Processing, vol. 80, pp. 2121--2140, Oct. 2000.
  2. S. O. Aase, J. H. Husøy, K. Skretting, and K. Engan, ``Optimised signal expansions for sparse representation,?? IEEE Trans. Signal Processing, vol. 49, pp. 1087--1096, May 2001.
  3. K. Kreutz-Delgado, J. F. Murray, B. D. Rao, K. Engan, T.W. Lee, and T. Sejnowski  ``Dictionary Learning Algorithms for Sparse Representation,?? Neural Computation, no 15, pp. 349?396, 2003.
  4. B. D. Rao, K. Engan, S. Cotter, J. Palmer, K. Kreutz-Delgado ``Subset Selection in Noise Based on Diversity Measure  Minimization,''IEEE Trans. on Signal Processing, vol. 51, no. 3, pp. 760--770, March 2003.
  5. S. Cotter, B. D. Rao, K. Engan, K. Kreutz-Delgado ``Sparse Solutions to Linear Inverse Problems with Multiple Measurement Vectors,?  IEEE Trans. on Signal Processing 2005, vol. 53, no. 7, pp. 2477-2488, July 2005.
  6. K.Engan, T.O.Gulsrud, ?VarMet ? a method for detection of image singularities with applications to mammography?, WSEAS Transactions on Signal Processing, Issue 9, Volume 2, pp. 1222-1229, sept 2006.
  7. K.Engan, K. Skretting, J.H. Husøy ?A Family of Iterative LS-Based Dictionary Learning Algorithms, ILS-DLA, for Sparse Signal Representation?, Digital Signal Processing, Volume 17, Issue 1, pp 32-49, Jan 2007, http://dx.doi.org/10.1016/j.dsp.2006.02.002
  8. K.Engan, K.Skretting, J. Herredsvela, T.O. Gulsrud, ?Frame Texture Classification Method (FTCM) Applied on Mammograms for Detection of Abnormalities?,  WASET International Journal of Signal Processing (IJSP), Volume 4, No 2, ISSN 1304-4478, 2007, http://www.waset.org/ijsp/v4/v4-2-16.pdf
  9. K.Engan, T.O.Gulsrud, K.F. Fretheim, B. Furebotten Iversen, L. Eriksen ?A Computer Aided Detection (CAD) System for Microcalcifications in Mammograms ? MammoScan ?CaD?, WASET, International Journal of Bimodeical Sciences (IJBS), Volume 2, No 3, pp 168-179, ISSN 1306-1216, 2007,  http://www.waset.org/ijbs/v2/v2-3-24.pdf
  10. K.Skretting, K.Engan  ?Recursive least squares dictionary learning algorithm?, IEEE Trans. Signal Processing, vol. 58, no. 4, pp. 2121-2130, 2010.

Conference publications:

  1. K. Engan, S. O. Aase, and J. H. Husøy,  ``Transform based   ECG signal compression using nonorthogonal vectors,'' in Proc. NORSIG '97 , Tromsø, Norway, May 1997, pp. 140--145.
  2. K. Engan, S. O. Aase, and J. H. Husøy, ``Designing frames for matching pursuit algorithms,'' in Proc. ICASSP ?98, Seattle, USA, May 1998, pp. 1817--1820.
  3. K. Engan, J. H. Husøy, and S. O. Aase, ``Optimized frame design for a matching pursuit based compression scheme,'' in Proc. EUSIPCO ?98, Rhodes, Greece, Sept. 1998, pp. 153--156.
  4. K. Engan, J. H. Husøy, and S. O. Aase, ?Optimized frames of variable size for use in a matching pursuit based compression scheme,? in   Proc. NORSIG ?98, Vigsø, Denmark, June 1998, pp. 277--280.
  5. K. Engan, S. O. Aase, J. H. Husøy, ?Method of Optimal Directions for Frame Design,? in   Proc. ICASSP?99, Phoenix, USA, pp. 2443--2446, March, 1999.
  6. K. Kreutz-Delgado, B. D. Rao, K. Engan, T.-W. Lee, and T. Sejnowski, ``Convex/schur-convex ( CSC ) log-priors and sparse coding,'' in   Proc. 6th joint symp. on Neural Comp. , Pasadena, USA, May 1999, vol. 9, pp. 65--71.
  7. K. Kreutz-Delgado, B. D. Rao, K. Engan, T. W. Lee, and T. Sejnowski, ``Learning overcomplete dictionaries: Convex/schur-convex (CSC) log-priors, factorial codes, and independent/dependent component analysis (I/DCA),'' in   Proc. 6th joint symp. on Neural Comp. , Pasadena, USA, May 1999, vol. 9, pp. 72--78.
  8. K. Engan, S. O. Aase, and J. H. Husøy, ``Frame based signal compression using method of optimal directions  (MOD),'' in   Proc. ISCAS?99, Orlando, USA, June 1999, pp. IV--1--IV--4.
  9. J. H. Husøy, S. O. Aase, K. Skretting, and K. Engan, ``Design of general block oriented expansions for efficient signal representation,'' in   Proc. ISCAS?99, Orlando, USA, June 1999, pp. III--9--III--12.
  10. K. Engan, B. Rao, and K. Kreutz-Delgado, ``Frame design using FOCUSS with method of optimized directions (MOD),'' in Proc. NORSIG ?99, Oslo, Norway, Sept. 1999, pp. 65--69.
  11. K. Kreutz-Delgado, B. D. Rao, and K. Engan, ``Novel algorithms for learning overcomplete dictionaries,'' in   Proc. of the 33 Asilomar Conference on Signals, Systems and Computers, Monterey, California, 1999.
  12. K. Engan, B. Rao, and K. Kreutz-Delgado, ``Regularized FOCUSS for subset selection in noise,'' in Proc. of NORSIG 2000, Sweden, June 2000, pp. 247--250.
  13. S. O. Aase, K. Skretting, J. H. Husøy, and K. Engan, ``Design of signal expansions for sparse representation,'' in   Proc. ICASSP'00, Istanbul, Turkey, June 2000.
  14. K. Skretting, K. Engan, J. H. Husøy, and S. O. Aase, ``Sparse representation of images using overlapping frames,'' in   Proc. SCIA'01, Bergen, Norway, June 2001.
  15. J. E. Odegard, K. Engan, T. O. Gulsrud, and A. Rettedal, ``Redesign of introductory course in electrical and computer engineering at Stavanger university college,'' in   Proc. ICEE?01, Oslo, Norway, Aug. 2001.
  16. K. Engan, J. H. Husøy, and S. O. Aase, ``Frame based representation and compression of still images,''  in   Proc. ICIP'01 , Thesaloniki, Greece, Oct. 2001.
  17. K. Engan and J. R. Akselsen, ``Comparison of frame based coding (FBC) with multi stage vector quantization (MSVQ),'' in   Proc. NORSIG ?01, Trondheim, Norway, Oct. 2001, pp. 123--128.
  18. K. Engan, K. Skretting, ``A Novel Image Denoising Technique Using Overlapping Frames,'' in   Proc. of 2nd. IASTED Int. Conf. on Visualization, Imaging, and Image Processing, Malaga, Spain, pp. 265--270, September, 2002.
  19. K. Engan, T. O. Gulsrud, and K. R. Josefsen, ``Watermarking of Digital Mammograms Without Interfering with Automatic Detection of Microcalcifications,'' in   Proc. of ICIP 2003, Barcelona, Spain, September 2003.
  20. K. F. Fretheim, and K. Engan, ?Comparison of Four Wavelet-Based Methods for Compression of ECG Signals,? in   Proc. NORISG 2003, Bergen, Norway, Oct. 2003.
  21. K. Engan, and K. F. Fretheim, and T. O. Gulsrud, ``Compression of Digital Mammograms without Interfering with a System for Automatic Detection of Microcalcifications - MammoScan mCaD '' in   Proc. NOBIM 2004, Stavanger, Norway, May. 2004.
  22. B. Rao, and K. Engan, and S. Cotter, ?Diversity Measure Minimization Based Method for Computing Sparse Solutions to Linear Inverse Problems with Multiple Measurement Vectors,'' in   Proc. ICASSP 2004, Montreal, Canada, May. 2004.
  23. K. Engan, M. Lillo, T.O. Gulsrud ?Compression of Digital Mammograms with Region-of-interest Coding Evaluated on a CAD System?, in Proc. Medical Imaging 2005, SPIE conference, Feb. 2005, San Diego, USA, pp. 1018--1027.
  24. T.O. Gulsrud, K. Engan, J. Herredsvela ?Feature Extraction in Digital Mammograms Based on Optimal and Morphological Filtering?, in Proc. Medical Imaging 2005, SPIE conference, Feb. 2005, San Diego, USA, pp. 1093--1103.
  25. J. Herredsvela, T.O. Gulsrud, K. Engan, ?Detection of Masses in Mammograms Using Morphological Segmentation?, in Proc. Medical Imaging 2005, SPIE conference, Feb. 2005, San Diego, USA, pp. 902--913.
  26. K. Engan, K. Skretting, J.H. Husøy ?Denoising of Images Using Signal Dependent Frames and Matching Pursuit?,  in Proc. ICASSP 2005, Philadelphia, USA, march 2005.
  27. K. Skretting, K. Engan, J.H. Husøy ?ECG Compression Using Signal Dependent Frames and Matching Pursuit?, in Proc. ICASSP 2005, Philadelphia, USA, march 2005.
  28. T.O. Gulsrud, K. Engan and T. Hanstveit ? Watershed segmentation of detected masses in digital mammograms? in Proc. EMBC 2005, september 2005, Shanghai, China.
  29. E. Kristoffersen, I.Austvoll. K.Engan ? Dense Motion Field Estimation Using Spatial Filtering and Quasi Eigenfunction Approximations?, in Proc. ICIP 2005,  September 2005, Genova, Italia
  30. J.Tjøtta, K.Engan, T.O. Gulsrud, I. Skaland, E.A.M. Janssen , and J.P.A. Baak, ?Automatic Counting and Classifying of Cell-Nuclei in a Tissue Section?, Proc. of  NORISG 2005, Stavanger, Norway, sept. 2005.
  31. J. Herredsvela, K. Engan, T.O. Gulsrud, K. Skretting, ?Detection of  Masses in Mammograms by Watershed Segmentation and Sparse Representasions Using Learned Dictionaries?, Proc. of NORISG 2005, Stavanger, Norway, sept. 2005.
  32. J.Herredsvela, K.Engan, T.O.Gulsrud, K.Skretting, ? Detection of lesions in mammograms using learned dictionaries and sparse representations?, Proc. of EMBEC?05, Prague
    Czech Republic , Nov. 2005.
  33. J.Herredsvela, K.Engan, T.O.Gulsrud, K.Skretting,  ?Texture classification using sparse representations by learned compound dictionaries?, Proc. of SPARS?05, Rennes, France, nov 2005.
  34. T.O.Gulsrud, K.Engan, J.Herredsvela, ?VarMet- A Novel Method for Detection of Image Singularities?,  Proc. of WSEAS int.conf. on Signal, Speech and Image Proc. 2006 (SSIP?06), Lisbon Portugal, sept 2006.
  35.  K.Engan, T.Eftestøl, S.Ørn, J.T. Kvaløy, L.Woie, ? Exploratory Data Analysis of Image Texture and Statistical Features on Myocardium and Infarction Areas in Cardiac Magnetic Resonance Images? Proc. of EMBC 2010, september 2010, Buenos Aires, Argentina.

Current research

Work experience

2008 ? present:  Professor, dept. of Electrical Eng. and Comp. Science, University of Stavanger, Norway

2000 ? aug 2008:  Associate professor, dept. of Electrical Eng. and Comp. Science, University of Stavanger, Norway

Feb 2008 ? april 2009:  Maternity leave
Jan 2006 ? jan 2007:  Maternity leave

2003 ? 2005:  Researcher at MammoScan AS ,