Selim Benhimane, Dr. Eng. Boltzmannstr. 3 85748 Garching b. München Germany How to get there tel: +49 (0)89 289-17081 fax: +49 (0)89 289-17059 room: MI 03.13.043

Background

Since 2005	Research Associate at the CAMPAR team Technische Universität München, with Prof. Dr. Nassir NAVAB In charge of the Computer Vision Group
2002-2005	Ph.D. from École Nationale Supérieure des Mines de Paris and prepared at the ICARE team INRIA Sophia Antipolis. Supervised by Dr. Ezio MALIS Toward a unified approach to real-time visual tracking and servoing. Jury: Prof. Yves Rouchaleau, Dr. Francois Chaumette, Dr. Michel Dhome, Prof. Nassir Navab, Dr. Ezio Malis, Dr. Patrick Rives. Degree: Docteur en Sciences. Specialization: Real-time systems, Control and Robotics. Passed with the highest distinction (mention Très Honorable et les Félicitations du Jury). Prize of Best French Ph.D. of the two years 2005 & 2006 in Applied and Innovative Research by ASTI
2001-2002	Postgraduate advanced diploma (DEA): "Photonics, Imaging et Cybernetics'' in the Control and Vision specialization, Louis Pasteur University , Strasbourg, France. Passed with the highest distinction (mention Très Bien). Ranked 1st over all the specializations.
1999-2002	Engineering degree from the E.N.S.P.S. National School of Higher Education in Physics of Strasbourg, France. 3rd year specialization: Engineering systems, Automation and Vision.
1997-1999	Classes préparatoires scientifiques: two-year post-'A'-level preparatory courses for entrance exams to French engineering schools
1997	Baccalaureat in Mathematics (Equivalent to A-levels). Passed with the highest distinction (mention Très Bien).

General Research Topics

• Computer Vision
• Augmented Reality
• Robotics and Vision-based control
• Intrinsics-free visual servoing
• Model measure-free visual servoing
• Image matching and Tracking initialization
• Camera self-calibration
• Real-time image-based tracking

Current Research Projects

Vision Targeted CAD Models This project investigates vision features and their intelligent application on known CAD models for pose estimation. The advantage of combining CAD models and vision features lies in the known 3D geometry of the CAD model. Exemplary vision features are e.g. SIFT features, Randomized Trees, SURF features and other well known methods. The main goal is to use such an extended CAD model for pose estimation and for tracking initialization.

Camera Augmented Mobile C-arm The problem of positioning mobile C-arms, e.g. for down the beam techniques, as well as repositioning during surgical procedures currently requires time, skill and additional radiation. The Camera-Augmented Mobile C-arm (CAMC) is able to speed up the procedure, simplify its execution and reduce the necessary radiation. The C-arm is extended by a CCD camera. The CCD camera is attached to the C-arm such that it is virtually at the same location than the x-ray source. This is done by a double mirror construction. A two step calibration routine has be done only once at the moment the camera is attached. Extensions for a lightwight, but complete navigation system for pedile screw placement or implant positioning is currently under investigation.

Discrepancy Check Using Augmented Reality Construction companies employ CAD software during the planning phase but what is finally built often does not match the original plan. The procedure of validating the model is called 'discrepancy check'. The system proposed here allows the user to easily obtain an augmentation in order to find differences between the planned 3D model and the built items. The main difference to previous body of work in this field is the emphasis on usability and acceptance of the solution. While standard image-based solutions use markers or rely on a 'perfect' 3D model to find the pose of the camera; our software uses Anchor-Plates. Anchor-Plates are rectangular structures installed on walls and ceiling in the majority of industrial edifices. We are using them as landmarks because they are the most reliable components often used as reference coordinates by constructors. Furthermore; for real industrial applications; they are the most suitable solutions in terms of general applicability. For this project we try to bring a innovative solution to the discrepancy check procedure by applying Augmented Reality.

Hybrid Tracking In this project a complete real-time model-based tracking system for piecewise-planar objects which combines template-based and feature-based approaches is being developed. The main contributions are an extension to the ESM algorithm used for template-based tracking and the formulation of a feature-based tracking approach, which is specifically tailored for use in a real-time setting. In order to cope with highly dynamic scenarios, such as illumination changes, partial occlusions and fast object movement, the system adaptively switches between template-based tracking, feature-based tracking and a global initialization phase. The tracking system achieves real-time performance by applying a coarse-to-fine optimization approach and includes means to detect a loss of track.

Real-Time 3D Reconstruction We are working on a real-time 3D reconstruction system aimed at recovering the 3D shape of objects inside a working area using only camera images. The working area is observed by 16 cameras mounted on the ceiling. Using these images we reconstruct an occupancy map and extract individual objects. The long-term goal of the project is to use this occupancy map to detect possible collisions between a robot placed in the working area and other objects in its path.

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Intensity-based Tracking? In this project, we are interested in the fundamental problem of simultaneously tracking a piecewise-planar scene and accurately estimating the 3D displacement of the camera. The objective is to have an algorithm with a higher convergence frequency and a higher convergence rate than standard optimization methods while having an equivalent computational complexity. Since the tracking is aimed to be used in industrial real-time augmented reality applications, in addition to the robustness and the speed performance, the algorithm should be very precise. For some applications, we are investigating alternatives where an off-line learning step improves the efficiency and the convergence properties of the tracking algorithm.

Deformable Shape Matching This project aims a real-time detection of two dimensional deformable patterns for industrial inspection. The fast, robust and accurate localization of a given 2D object template in images has been a research topic since many decades. The results of this research efforts has enabled numerous different industrial applications, as the detection of the objects pose is the natural prerequisite for any senseful operation like counting, defect detection or pick and place operations. In case that the object to be localized is rigid or articulated, different successful approaches have been proposed and are applied in everyday industrial practice. Various applications domains, which necessitate the detection of deformable objects, like medical, packaging, textile or paper industry, can still not be comprehensively solved. The goal of current research is the development of a method which is fast, robust to illumination changes, occlusion and clutter plus allows the objects shape to deform.

Main Publications

2009
	L. Wang, J. Traub, S.M. Heining, S. Benhimane, R. Graumann, E. Euler, N. Navab Long Bone X-ray Image Stitching using C-arm Motion Estimation Proceedings of Bildverarbeitung fuer die Medizin (BVM 2009), Heidelberg, Germany, March 2009 (to be published) (bib)
2008
	P. Georgel, P. Schroeder, S. Benhimane, M. Appel, N. Navab How to Augment the Second Image? Recovery of the Translation Scale in Image to Image Registration The 7th IEEE and ACM International Symposium on Mixed and Augmented Reality, Cambridge, UK, Sept. 15 - 18, 2008. (bib)
	S. Hinterstoisser, S. Benhimane, V. Lepetit, P. Fua, N. Navab Simultaneous Recognition and Homography Extraction of Local Patches with a Simple Linear Classifier British Machine Vision Conference (BMVC), Leeds (UK), September 1-4, 2008 (bib)
	A. Ladikos, S. Benhimane, N. Navab Multi-View Reconstruction using Narrow-Band Graph-Cuts and Surface Normal Optimization British Machine Vision Conference (BMVC), Leeds (UK), September 1-4, 2008 (bib)
	P. Georgel, S. Benhimane, N. Navab A Unified Approach Combining Photometric and Geometric Information for Pose Estimation British Machine Vision Conference (BMVC), Leeds (UK), September 1-4, 2008 (bib)
	L. Wang, J. Traub, S.M. Heining, S. Benhimane, R. Graumann, E. Euler, N. Navab Long Bone X-ray Image Stitching Using Camera Augmented Mobile C-arm Medical Image Computing and Computer-Assisted Intervention, MICCAI, 2008, New York, USA, September 6-10 2008 (bib)
	A. Ladikos, S. Benhimane, N. Navab Real-time 3D Reconstruction for Collision Avoidance in Interventional Environments Medical Image Computing and Computer-Assisted Intervention, MICCAI, 2008, New York, USA, September 6-10 2008 (bib)
	S. Atasoy, D. Noonan, S. Benhimane, N. Navab, G. Z. Yang A Global Approach for Automatic Fibroscopic Video Mosaicing in Minimally Invasive Diagnosis Medical Image Computing and Computer-Assisted Intervention, MICCAI, 2008, New York, USA, September 6-10 2008 (bib)
	A. Ladikos, S. Benhimane, N. Navab Efficient Visual Hull Computation for Real-Time 3D Reconstruction using CUDA IEEE Computer Society Conference on Computer Vision and Pattern Recognition, Anchorage, Alaska (USA), June 2008. Workshop on Visual Computer Vision on GPUs (CVGPU) (bib)
	S. Hinterstoisser, S. Benhimane, N. Navab, P. Fua, V. Lepetit Online Learning of Patch Perspective Rectification for Efficient Object Detection IEEE Computer Society Conference on Computer Vision and Pattern Recognition, Anchorage, Alaska (USA), June 2008. (bib)
	R. Lasowski, S. Benhimane, J. Vogel, T. F. Jakobs, C. J. Zech, C. Trumm, M. Brokate, N. Navab Adaptive visualization using the annealing M-estimator Workshop Bildverarbeitung für die Medizin, Berlin, Germany, April 6-8, 2008 (bib)
	R. Lasowski, S. Benhimane, J. Vogel, T. F. Jakobs, C. J. Zech, C. Trumm, Ch. Clason, N. Navab Adaptive visualization for needle guidance in RF Liver Ablation: taking organ deformation into account SPIE Medical Imaging, San Diego, California, USA, February 16-21, 2008 (bib)
	A. Ladikos, S. Benhimane, M. Appel, N. Navab Model-Free Markerless Tracking for Remote Support in Unknown Environments International Conference on Computer Vision Theory and Applications, Funchal, Portugal, January 2008. (bib)
	S. Benhimane, H. Najafi, M. Grundmann , E. Malis, Y. Genc, N. Navab Real-time object detection and tracking for industrial applications International Conference on Computer Vision Theory and Applications, Funchal, Portugal, January 2008. (bib)
2007
	P. Georgel, P. Schroeder, S. Benhimane, S. Hinterstoisser, M. Appel, N. Navab An Industrial Augmented Reality Solution For Discrepancy Check Proceedings of the 6th International Symposium on Mixed and Augmented Reality (ISMAR), Nara, Japan, Nov. 2007 (bib)
	S. Hinterstoisser, S. Benhimane, N. Navab N3M: Natural 3D Markers for Real-Time Object Detection and Pose Estimation IEEE International Conference on Computer Vision, Rio de Janeiro, Brazil, October 14-20, 2007 (bib)
	S. Benhimane, E. Malis Homography-based 2D Visual Tracking and Servoing Special Joint Issue IJCV/IJRR on Robot and Vision. Published in The International Journal of Robotics Research, Volume 26, No. 7, 661-676, July 2007. (bib)
	S. Benhimane, A. Ladikos, V. Lepetit, N. Navab Linear and Quadratic Subsets for Template-Based Tracking IEEE Computer Society Conference on Computer Vision and Pattern Recognition, Minneapolis, Minnesota, June 2007 (bib)
	T. Klein, S. Benhimane, J. Traub, S.M. Heining, E. Euler, N. Navab Interactive Guidance System for C-arm Repositioning without Radiation Proceedings of Bildverarbeitung fuer die Medizin (BVM 2007), Munich, Germany, March 2007, pp. 21-25 (bib)
	A. Ladikos, S. Benhimane, N. Navab A Real-Time Tracking System Combining Template-Based and Feature-Based Approaches International Conference on Computer Vision Theory and Applications, Barcelona, Spain, March 2007. (bib)
2006
	S. Benhimane Vers une approche unifiee pour le suivi temps-reel et l’asservissement visuel PhD Thesis - These de doctorat a l'Ecole Nationale Superieure des Mines de Paris, December 2006 (bib)
	S. Benhimane, E. Malis Integration of Euclidean constraints in template-based visual tracking of piecewise-planar scenes IEEE/RSJ International Conference on Intelligent Robots Systems, Beijing, China, October 2006. (bib)
	C. Mei, S. Benhimane, E. Malis, P. Rives Homography-based Tracking for Central Catadioptric Cameras IEEE/RSJ International Conference on Intelligent Robots Systems, Beijing, China, October 2006. (bib)
	N. Navab, S. Wiesner, S. Benhimane, E. Euler, S.M. Heining Visual Servoing for Intraoperative Positioning and Repositioning of Mobile C-arms Proceedings of Medical Image Computing and Computer-Assisted Intervention (MICCAI 2006), Copenhagen, Denmark, October 2006 (bib)
	C. Mei, S. Benhimane, E. Malis, P. Rives Constrained Multiple Planar Template Tracking for Central Catadioptric Cameras British Machine Vision Conference, Edinburgh, UK, September 2006. (bib)
	S. Benhimane, E. Malis A new approach to vision-based robot control with omni-directional cameras IEEE International Conference on Robotics and Automation, Orlando, USA, May 2006. (bib)
	S. Benhimane, E. Malis Homography-based 2D Visual Servoing IEEE International Conference on Robotics and Automation, Orlando, USA, May 2006. (bib)
	S. Benhimane, E. Malis Une approche directe pour l'asservissement visuel 2D 15eme Congres Francophone AFRIF-AFIA de Reconnaissance des Formes et Intelligence Artificielle, Tours, France, January 2006. (bib)
2005
	E. Malis, S. Benhimane A unified approach to visual tracking and servoing. Robotics and Autonomous Systems, Volume 52, Issue 1, Pages 39-52, 31 July 2005. (bib)
	S. Benhimane, E. Malis, P. Rives, J. R. Azinheira Vision-based Control for Car Platooning using Homography Decomposition IEEE International Conference on Robotics and Automation, pp. 2173-2178, Barcelona, Spain, April 2005. (bib)
2004
	E. Malis, S. Benhimane A unified framework for real-time visual tracking and servoing IEEE/RSJ International Conference on Intelligent Robots and Systems, Sendai, Japan, October 2004. Workshop WWF4 Advances in Robot Vision - From Domestic Environments to Medical Applications. (bib)
	S. Benhimane, E. Malis Self-calibration of the distortion of a zooming camera by matching points at different resolutions IEEE/RSJ International Conference on Intelligent Robots and Systems, vol. 2, pp. 2307-2312, Sendai, Japan, October 2004. (bib)
	S. Benhimane, E. Malis Real-time image-based tracking of planes using Efficient Second-order Minimization IEEE/RSJ International Conference on Intelligent Robots and Systems, vol. 1, pp. 943-948, Sendai, Japan, October 2004. (bib)
	S. Benhimane, E. Malis Mise en correspondance d'images a differentes resolutions a l'aide d'invariants aux parametres intrinseques 14eme Congres Francophone AFRIF-AFIA de Reconnaissance des Formes et Intelligence Artificielle, Toulouse, France, January 2004. (bib)
2003
	S. Benhimane, E. Malis Vision-based control with respect to planar and non-planar objects using a zooming camera IEEE International Conference on Advanced Robotics, vol. 2, pp. 991-996, Coimbra, Portugal, July 2003. (bib)

Journals Scientific Reviews

• IEEE Transactions on Pattern Analysis and Machine Intelligence
• IEEE Transactions on Control Systems Technology
• Pattern Recognition Letters - Elsevier Science

Teaching Assistance

Summer Term 2006

• Hauptseminar Applications of Computer Vision for Industrial Augmented Reality
• Praktikum 3D Computer Vision

Winter Term 2006/2007

• Lecture Basic Mathematical Tools for Imaging and Visualization
• Lecture 3D Computer Vision

Summer Term 2007

• Lecture 3D Computer Vision II
• Praktikum 3D Computer Vision for Special Effects

Winter Term 2007/2008

• Lecture Basic Mathematical Tools for Imaging and Visualization
• Lecture 3D Computer Vision

Summer Term 2008

• Lecture 3D Computer Vision II
• Praktikum 3D Computer Vision for Special Effects

Student Projects (SEPs, IDPs, Bachelor/Master/Diploma Theses)

Running

• Image Segmentation for Occupancy Map Reconstruction , Master Thesis by Nuno Barreiro (16.10.07)
• Implementation of an AR application for robust marker detection, SEP by Ivan Borisov (15.12.2006)

Finished

• Visual Servoing for Camera Augmented Mobile C-arm, IDP by Thomas Weich (2008/03/15)
• Contributions for building specific CAD models for vision-based application, Diploma Thesis by Stefan Hinterstoisser (2007/01/15)
• Towards Robust Markerless Tracking: Combining Feature-based and Intensity-based Approaches, Diploma Thesis by Alexander Ladikos (2006/11/15)