Gavriil Tsechpenakis, Ph.D.

Gavriil Tsechpenakis, Ph.D.

Associate Professor, Computer & Information Science

Office:
UH 5015
Phone:
(317) 274-9727
Email:
gtsechpe@iu.edu
Research Areas:
Imaging & Visualization Research Group

Research

Biomedical vision, computational biology, computer vision, and pattern recognition are the domains of Dr. Tsechpenakis' research. He works with image segmentation with deformable models and learning-based classification approaches, object recognition, feature tracking, 3D shape estimation and tracking of articulated and deformable structures, 3D shape recovery from 2D data, high throughput spatio-temporal analysis, content-based image retrieval, human motion analysis, temporal change-point detection, and semantic knowledge extraction.

Education

  • Diploma Electrical & Computer Engineering, National Technical University of Athens Greece, 1999
  • Ph.D. National Technical University of Athens Greece, 2003

Publications & Professional Activity

2016

  • S. Gulyanon, N. Sharifai, M.D. Kim, A. Chiba, and G. Tsechpenakis, "CRF formulation of active contour population for efficient three-dimensional neurite tracing," Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Prague, Czech Republic, 2016.
  • S. Farhand, S. Gulyanon, N. Sharifai, M.D. Kim, A. Chiba, and G. Tsechpenakis, "Temporal neurite registration using hierarchical alignments," Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Prague, Czech Republic, 2016.

2015

  • S. Gulyanon, N. Sharifai, S. Bleykhman, E. Kelly, M.D. Kim, A. Chiba, and G. Tsechpenakis, "Three-dimensional neurite tracing under globally varying contrast," Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Brooklyn, NY, 2015.
  • N. Hammes, L. Racette, B.C. Samuels, and G. Tsechpenakis, "Retinal thickness estimation from SD-OCT Macular scans," Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Brooklyn, NY, 2015.

2014

  • B. Tan, A.D. Graham, G. Tsechpenakis, and M.C. Lin, "A Novel Analytical Method Using OCT to Describe the Corneoscleral Junction," Optometry and Vision Science, 91(6):650-657, 2014.
  • X. Chang, M.D Kim, R. Stephens, T. Qu, A. Chiba, and G. Tsechpenakis, "Part-based motor neuron recognition in the Drosophila ventral nerve cord", Elsevier NeuroImage, 90:33-42, 2014.
  • X. Chang, M.D Kim, R. Stephens, T. Qu, A. Chiba, and G. Tsechpenakis, "Neuron Recognition with Hidden Neural Network Random fields", Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Beijing, China, 2014.
  • [abstract] B.C. Samuels, N.M. Hammes, L. Racette, and G. Tsechpenakis"Analysis of Macular Retinal Thickness in Arcuate Bins for Glaucoma Detection," The Association for Research in Vision and Ophthalmology (ARVO), 2014.
  • [abstract] B. Tan, Y. Zhou, T. Yuen, A.D. Graham, G. Tsechpenakis, and M.C. Lin, "Fluorogram of post-lens tear mixing under soft contact lenses ," The Association for Research in Vision and Ophthalmology (ARVO), 2014.

2013

  • P. Mukherjee, M.D Kim, A. Chiba, and G. Tsechpenakis, "Active Geometric Model: Application to neuron morphology estimation in the Drosophila ventral nerve cord", Int'l Conference on Image Processing (ICIP), Melbourne, Australia, 2013.
  • X. Chang, M.D Kim, A. Chiba, and G. Tsechpenakis, "Motor Neuron Recognition in the Drosophila Ventral Nerve Cord", Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), San Francisco, USA, 2013.
  • S. Farhand, F.M Andreopoulos, and G. Tsechpenakis, "CRF-driven Multi-compartment Geometric Model," Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), San Francisco, USA, 2013.

2012

  • S. Farhand, R.B. Montero, X. Vial, D.T. Nguyen, M. Reardon, S.M. Pham, F.M. Andreopoulos, and G. Tsechpenakis, "Probabilistic Multi-compartment Geometric Model: Application to Cell Segmentation," Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Barcelona, Spain, 2012.
  • X. Chang, M.D. Kim, A. Chiba, and G. Tsechpenakis, "Patterning Motor Neurons in the Drosophila Ventral Nerve Cord using Latent State Conditional Random Fields," Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Barcelona, Spain, 2012.
  • G. Tsechpenakis, P. Mukherjee, M.D. Kim and A. Chiba, "Three-dimensional Motor Neuron Morphology Estimation in the Drosophila Ventral Nerve Cord," IEEE Trans Biomedical Engineering, 59(5), pp. 1253-1263, 2012.
  • R.B. Montero, X. Vial, D.T. Nguyen, S. Farhand, M. Reardon, S.M. Pham, G. Tsechpenakis, and F.M. Andreopoulos, "bFGF-containing electrospun gelatin scaffolds with controlled nano-architectural features for directed angiogenesis," Acta Biomaterialia, 8(5), pp. 1778-1791, 2012.
  • S.P. Chatzis and G. Tsechpenakis, "A Possibilistic Clustering Approach Towards Generative Mixture Models," Pattern Recognition, 45(5), pp. 1819-1825, 2012.
  • [abstract] X. Chang, A. Kale, L. Dodge, J. Brazill, M.D. Kim, and G. Tsechpenakis, "Computer-aided Estimation of the Motor Neuron Morphology Patterns," Drosophila Genetics, Chicago, IL, 2012. [Selected for platform presentation]
  • [abstract] P. Mukherjee, J. Brazill, M.D. Kim, and G. Tsechpenakis, "Description and Visualization of Motor Neuron Morphology in Three Dimensions," Drosophila Genetics, Chicago, IL, 2012.
  • [abstract] B. Tan, A.D. Graham, Y. Zhou, A. Ghanekar, J. Nimi, W. Li, G. Tsechpenakis, and M.C. Lin, "A novel analytical method to quantitatively describe the corneoscleral junction using oprical coherence tomography," The Association for Research in Vision and Ophthalmology (ARVO), 2012.

2011

  • G. Tsechpenakis and S.P. Chatzis, "Deformable Probability Maps: Probabilistic Shape and Appearance-based Object Segmentation," Computer Vision and Image Understanding, 115(8), pp. 1157-1169, 2011.
  • G. Tsechpenakis, R. Egoda Gamage, M.D. Kim and A. Chiba, "Motor Neuron Morphology Estimation for its Classification in the Drosophila Brain," IEEE Engineering in Medicine and Biology Conference, Boston, MA, Sept. 2011.
  • G. Tsechpenakis, "Deformable Model-based Medical Image Segmentation," Chapt. 2 in Multi Modality State-of-the-Art Medical Image Segmentation and Registration Methodologies (Vol. 1), A.S. El-Baz, R.U. Acharya, M. Mirmehdi (eds.), Springer Publishing, 2011.
  • H. Layman, X. Li, E. Nagar, A. Azar, S.M. Pham, G. Tsechpenakis, and F.M. Andreopoulos, "Synergistic angiogenic effect of co-delivering FGF-2 and G-CSF from fibrin scaffolds and bone marrow transplantation in critical limb ischemia," Tissue Engineering, Part A, 17(1-2), pp. 243-254, 2011.
  • [abstract] J. Brazill, X. Chang, G. Tsechpenakis, and M.D. Kim, "Identification of genes that regulate patterning in motor neuron dendrites," Neurobiology of Drosophila, Cold Spring Harbor Laboratory, NY, 2011.
  • [abstract] J.D. Baker, J. Bixby, W. Buchser, M. Blulina, X. Cai, S. Deng, V. Gupta, N. Johnson, T. Kagesawa, D. Kamiyama, M. Kim, V. Lemmon, T. Li, M. Ogihara, H. Samarajeewa, N. Sharifai, R. Smith, G. Tsechpenakis, G. Zhai, A. Chiba, "The isPIN Project," 52nd Annual Drosophila Research Conference, San Diego, CA, March 2011.
  • [abstract] G. Tsechpenakis, H. Samarajeewa, M. Kim, A. Chiba, "Model Neurons of isPIN," 52nd Annual Drosophila Research Conference, San Diego, CA, March 2011.

2010

  • S. Chatzis, and G. Tsechpenakis, "The Infinite Hidden Markov Random Field Model," IEEE Trans on Neural Networks, 21(6), pp. 1004-1014, 2010.
  • A.W. Irvine, S. Chatzis, and G. Tsechpenakis, "Which Brainstem Cells Generate the Respiration Cycles?," Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Rotterdam, Netherlands, April 2010.
  • X. Huang and G. Tsechpenakis, "Medical Image Segmentation," Chapt. 10 in Information Discovery on Electronic Health Records, Chapman & Hall/CRC Data Mining and Knowledge Discovery Series, 2010.

2009

  • R.K. Cowen, C. Guigand, C. Cousin, G. Tsechpenakis, S. Chatzis, A. Greer, "An operational In Situ Ichthyoplankton Imaging System (ISIIS)," OceanObs, Venice, Italy, Sept. 2009.
  • S. Chatzis and G. Tsechpenakis, "The Infinite Hidden Markov Random Field Model," IEEE Int'l Conf. on Computer Vision (ICCV), Kyoto, Japan, Oct. 2009.
  • G. Tsechpenakis and D. Metaxas, "CoCRF Deformable Model: A Geometric Model Driven by Collaborative Conditional Random Fields," IEEE Trans. on Image Processing, 18(10), pp. 2316-2329, Oct. 2009.
  • K. J. Muller, G. Tsechpenakis, R. Homma, J. G. Nicholls , L. B. Cohen, and J. Eugenin, "Optical Analysis of Circuitry for Respiratory Rhythm in Isolated Brainstem of Foetal Mice," Phil. Trans. of the Royal Society B, 364, pp. 2485-2491, 2009.
  • G. Tsechpenakis, J. Eugenin, J.G. Nicholls, and K.J. Muller, "Analysis of the Nerve Activity and Optical Signals from Mouse Brain Stem to Identify Cells Generating Respiratory Rhythms," 6th Int'l Symposium on Biomedical Imaging: from Nano to Macro (ISBI), Boston, MA, June 2009.
  • M. Ruggeri, G. Tsechpenakis, S. Jiao, M.E. Jockovich, C. Cebulla, E. Hernandez, T.G. Murray, and C.A. Puliafito, "Retinal tumor imaging and volume quantification in mouse model using spectral-domain optical coherence tomography," Optics Express, 17(5), pp. 4074-4083, 2009.
  • M. Ruggeri, S. Jiao, J.C. Major, C. Cebulla, P. Rosenfeld, G. Gregori, G. Tsechpenakis, J. Wang, T. Murray, and V. Porciatti, "Ultra High-Resolution Optical Coherence Tomography for Ocular Imaging of Small Animals," 25th Southern Biomedical Engineering Conference, Miami, FL, 2009.

2008

  • G. Tsechpenakis, C. Guigand, and R.K. Cowen, "Machine Vision assisted In Situ Ichthyoplankton Imaging System," Sea Technology, 49(12), pp. 15-20, Dec. 2008.
  • M. Ruggeri, H. Wehbe, G. Tsechpenakis, S. Jiao, M.E. Jockovich, C. Cebulla, E. Hernandez, T.G. Murray, and C.A. Puliafito, "Quantitative Evaluation of Retinal Tumor Volume in Mouse Model of Retinoblastoma by using Ultra High-resolution Optical Coherence Tomography," Journal of Innovation in Optical Health Sciences, 1(1), pp. 17-28, 2008.
  • G. Tsechpenakis, B. Lujan, O. Martinez, G. Gregori, and P.J. Rosenfeld, "Geometric Deformable Model Driven by CoCRFs: Application to Optical Coherence Tomography," 11th Int'l Conf. on Medical Image Computing and Computer Assisted Intervention (MICCAI'08), NYC, NY, Sept. 2008.
  • G. Tsechpenakis, L. Bianchi, D. Metaxas, and M. Driscoll, "A Novel Computational Approach for Simultaneous Tracking and Feature Extraction of C. elegans Populations in Fluid Environments," IEEE Trans. on Biomedical Engineering, 55(5), pp. 1539-1549, May 2008.
  • O. Martinez, and G. Tsechpenakis, "Integration of Active Learning in a Collaborative CRF," IEEE Online Learning for Classification, CVPR 2008, Anchorage, AK, Jun. 2008.
  • G. Tsechpenakis, D. Metaxas, and C. Neidle, "Combining Discrete and Continuous 3D Trackers," Human Motion - Understanding, Modeling, Capture and Animation, Springer, 2008.

2007

  • G. Tsechpenakis, J. Wang, B. Mayer, and D. Metaxas, "Coupling CRFs and Deformable Models for 3D Medical Image Segmentation," IEEE Mathematical Methods in Biomedical Image Analysis, IEEE Int'l Conf. on Computer Vision, Rio de Janeiro, Brazil, Oct. 2007.
  • G. Tsechpenakis, L. Bianchi, M. Driscoll, and D. Metaxas, "Tracking C. elegans Populations in Fluid Environments for the Study of Different Locomotory Behaviors," 2nd Int'l Workshop on Microscopic Image Analysis with Applications in Biology, Piscataway, NJ, Sept. 2007.
  • G. Tsechpenakis, and D. Metaxas, "CRF-driven Implicit Deformable Model," IEEE Conference on Computer Vision and Pattern Recognition (CVPR'07), Minneapolis, MN, June 2007.
  • G. Tsechpenakis, and J. Wang, "CRF-based Segmentation of Human Tear Meniscus Obtained with Optical Coherence Tomography," IEEE International Conference on Image Processing (ICIP'07), San Antonio, TX, September 2007.
  • G. Tsechpenakis, C. Guigand, and R. Cowen, "Image analysis techniques to accompany a new In Situ Ichthyoplankton Imaging System (ISIIS)," IEEE OCEANS 2007, Aberdeen, Scotland, June 2007.

2006

  • D. Metaxas, G. Tsechpenakis, Z. Li, Y. Huang, and A. Kanaujia, "Dynamically Adaptive Tracking of Gestures and Facial Expressions," International Conference on Computational Science, The University of Reading, UK, May 2006.
  • G. Tsechpenakis, D. Metaxas, and C. Neidle, "Learning-based Coupling of Discrete and Continuous Trackers," Computer Vision and Image Understanding, 104(2-3), pp. 140-156, Nov/Dec 2006.
  • D. Metaxas, G. Tsechpenakis, Z. Li, Y. Huang, and A. Kanaujia, "Dynamically Adaptive Tracking of Gestures and Facial Expressions," Lecture Notes in Computer Science, Springer-Verlag, vol. 3993, pp. 554-561, 2006.
  • G. Tsechpenakis, L. Bianchi, L. Kotlyanskaya, D. Metaxas and M. Driscoll, "LocoWorm: A Program for Multiple Worms Tracking and Locomotion Features Extraction," Neuronal Development, Synaptic Function & Behavior, 2nd C. elegans Topic Meeting, Madison, Wisconsin, July 9-12, 2006.
  • G. Tsechpenakis, D. Metaxas, O. Hadjiliadis, and C. Neidle, "Robust Online Change-point Detection in Video Sequences," 2nd IEEE Workshop on Vision for Human Computer Interaction (V4HCI), in conjunction with IEEE Conference on Computer Vision and Pattern Recognition (CVPR'06), New York, NY, June 2006.

2005

  • T. O. Meservy, M. L. Jensen, J. Kruse, D. P. Twitchell, G. Tsechpenakis, J. K. Burgoon, D. N. Metaxas, J. F. Nunamaker Jr., "Deception Detection through Automatic Unobtrusive Analysis of Nonverbal Behavior," IEEE Intelligent Systems, Special Issue on Artificial Intelligence for National and Homeland Security, vol. 20(5), pp. 36-43, Sept/Oct 2005.
  • D. Metaxas and G. Tsechpenakis, "Dynamic Data Driven Coupling of Continuous and Discrete Methods for 3D Tracking," Lecture Notes in Computer Science, Springer-Verlag, vol. 3515, p. 712, April 2005.
  • G. Tsechpenakis, D. Metaxas, and C. Neidle, "Learning-based Dynamic Coupling of Discrete and Continuous Trackers," IEEE International Workshop on modeling People and Human Interaction (PHI'05), in conjunction with ICCV'05, Beijing, China, October 2005.
  • W. He, X. Huang, G. Tsechpenakis, D. Metaxas, and C. Neidle, "Discovery of Informative Unlabeled Data for Improved Learning," IEEE International Workshop on modeling People and Human Interaction (PHI'05), in conjunction with ICCV'05, Beijing, China, October 2005.
  • G. Tsechpenakis, D. Metaxas, M. Adkins, J. Kruse, M. Jensen, T. Meservy, D. Twitchell, A. Deokar and J. Nunamaker, "HMM-based Deception Recognition from Visual Cues," IEEE International Conference on Multimedia & Expo (ICME'05), Amsterdam, The Netherlands, July 2005.
  • G. Tsechpenakis, D. Metaxas and S. Lu, "Analysis and Recognition of Nonverbal Behavior Using 2D Visual Cues and Machine Learning," Project Panel: Machine Learning Technology for Recognition and Analysis of Suspicious Behavior from Human Gestures and Movement, 2nd Conference of the International Society for Gesture Studies (ISGS), Interacting Bodies, Lyon, France, June 2005.
  • D. Metaxas, and G. Tsechpenakis, "Dynamic Data Driven Coupling of Continuous and Discrete Methods for 3D Tracking," International Conference on Computational Science, (ICCS'05), Atlanta, USA, May, 2005.
  • S. Lu, G. Tsechpenakis, D. Metaxas, M. L. Jensen, and J. Kruse, "Blob Analysis of the Head and Hands: A Method for Deception Detection and Emotional State Identification," Hawaii International Conference on System Sciences, Big Island, Hawaii, January 2005.
  • J. Burgoon, M. Adkins, J. Kruse, M. L. Jensen, T. Meservy, S. Lu, G. Tsechpenakis, and D. Metaxas, "An Approach for Intent Identification by Building on Deception Detection," Hawaii International Conference on System Sciences, Big Island, Hawaii, January 2005.

2004

  • G. Tsechpenakis, K. Rapantzikos, N. Tsapatsoulis and S. Kollias, "A Snake Model for Object Tracking in Natural Sequences," Elsevier, Signal Processing: Image Communication, Vol. 19(3), pp. 219-238, March 2004. In the "10 most requested articles".
  • G. Tsechpenakis, K. Rapantzikos, N. Tsapatsoulis, S. Kollias, "Rule-driven Object Tracking in Clutter and Partial Occlusion with Model-based Snakes," EURASIP Journal on Applied Signal Processing, Special Issue on Object-based Semantic Image and Video Analysis, vol. 2004(6), pp. 841-860, June 2004.
  • G. Tsechpenakis, N. Tsapatsoulis and S. Kollias, "Probabilistic Boundary-Based Contour Tracking with Snakes in Natural Cluttered Video Sequences," International Journal of Image and Graphics (IJIG): Special Issue on Deformable Models for Image Analysis and Pattern Recognition, Vol. 4(3), pp. 469-498, 2004.
  • P. Tzouveli, G. Andreou, G. Tsechpenakis, Y. Avrithis and S. Kollias, "Intelligent Visual Descriptor Extraction from Video Sequences," Lecture Notes in Computer Science - Adaptive Multimedia Retrieval, Springer-Verlag, Vol. 3094, pp. 132-146, 2004.

2003

  • V. Tzouvaras, G. Tsechpenakis, G. Stamou and S. Kollias, "Adaptive Rule-based Recognition of Events in Video Sequences," IEEE International Conference on Image Processing (ICIP), Barcelona, Spain, September 2003.
  • P. Tzouveli, G. Andreou, G. Tsechpenakis, Y. Avrithis and S. Kollias, "Intelligent Visual Descriptor Extraction from Visual Sequences," International Workshop on Adaptive Multimedia Retrieval, KI 2003, Hamburg, Germany, September 2003.
  • G. Tsechpenakis, K. Rapatzikos, N. Tsapatsoulis and S. Kollias, "Object Tracking in Clutter and Partial Occlusion through Rule-driven Utilization of Snakes," IEEE International Conference on Multimedia & Expo, Baltimore, USA, July 2003.

2002

  • G. Tsechpenakis, G. Akrivas, G. Andreou, G. Stamou and S. Kollias, "Knowledge - Assisted Video Analysis and Object Detection," EUNITE 2002: European Symposium on Intelligent Technologies, Hybrid Systems and their Implementation on Smart Adaptive Systems, Albufeira, Portugal, September 2002.

2001

  • G. Tsechpenakis, Y. Xirouhakis and A. Delopoulos, "A Multiresolution Approach for Main Mobile Object Localization in Video Sequences," International Workshop on Very Low Bitrate Video Coding (VLBV01), Athens, Greece, October 2001.

2000

  • G. Tsechpenakis, Y. Xirouhakis, and A. Delopoulos, "Main Mobile Object Detection and Localization in Video Sequences," Lecture Notes in Computer Science - Advances in Visual Information Systems, Springer-Verlag, Vol. 1929, pp. 84-95, 2000.

1999

  • Y. Xirouhakis, G. Tsechpenakis and A. Delopoulos, "User Choices for Efficient 3D Motion and Shape Extraction from Orthographic Projections," The Sixth IEEE International Conference on Electronics, Circuits and Systems (ICECS99), Pafos, Cyprus, September 1999.
  • G. Tsechpenakis, Y. Xirouhakis and A. Delopoulos, "2D Motion Estimation in the Extraction of 3D Motion and Structure of Rigid Objects," International Workshop on Synthetic-Natural Hybrid Coding and 3D Imaging (IWSNHC3DI'99), Santorini, Greece, September 1999.
  • G. Tsechpenakis, Y. Avtithis and S. Kollias, "Verification Report of Core Experiment on Fast Block-Matching Motion Estimation using Advanced Diamond Zonal Search with Embedded Radar," International Organization for Standardization, ISO/IEC JTC1/SC29/WG11, MPEG99/M5116, October 1999.

Awards

  • Research Frontiers Trailblazer Award, May 2016
  • School of Science Research Award, May 2014
  • NSF CAREER Award: Modeling the Structure and Dynamics of Neuronal Circuits in the Drosophila larvae using Image Analytics [Jun 2013--May 2018]