Dr. Alexander Ladikos CTO at ImFusion GmbH

Real-time 3D reconstruction with RecFusion

RecFusion is a real-time 3D reconstruction software for RGB-D sensors! There is also a C++ SDK available for integrating real-time 3D reconstruction into your own applications. For more information visit the RecFusion homepage.

Research Interests

My research interests include 3D reconstruction from multiple views and optical tracking.

Projects

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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.

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.

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.

Workflow Analysis Using 4D Reconstruction Data This project targets the worklow analysis of an interventional room equipped with 16 cameras fixed on the ceiling. It uses real-time 3D reconstruction data and information from other available sensors to recognize objects, persons and actions. This provides complementary information to specific procedure analysis for the development of intelligent and context-aware support systems in surgical environments.

Diploma Thesis

Towards Robust Markerless Tracking: Combining Feature-based and Intensity-based Approaches

Publications

2018
	R. Prevost, M. Salehi, S. Jagoda, S. Kumar, J. Sprung, A. Ladikos, R. Bauer, O. Zettinig, W. Wein 3D Freehand Ultrasound without External Tracking using Deep Learning Medical Image Analysis, Volume 48, August 2018, Pages 187-202 (MICCAI Special Issue) (bib)
2017
	R. Prevost, M. Salehi, J. Sprung, A. Ladikos, R. Bauer, W. Wein Deep Learning for Sensorless 3D Freehand Ultrasound Imaging International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2017, Quebec City (bib)
2015
	W. Wein, A. Ladikos Method and tomography apparatus for reconstruction of a 3D volume US Grant US9135729B2 (bib)
2013
	W. Wein, A. Ladikos, B. Fuerst, A. Shah, K. Sharma, N. Navab Global Registration of Ultrasound to MRI using the LC2 Metric for Enabling Neurosurgical Guidance Proceedings of the 16th International Conference on Medical Image Computing and Computer Assisted Interventions (MICCAI), Nagoya, Japan, September 2013 (bib)
	W. Wein, A. Ladikos Towards General Motion Recovery in Cone-Beam Computed Tomography 12th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, June 16-21 2013, Lake Tahoe, CA USA (bib)
2012
	A. Ladikos, W. Wein Geometric calibration using bundle adjustment for cone-beam computed tomography devices SPIE Medical Imaging, February 2012, San Diego, USA. (bib)
	A. Aichert, W. Wein, A. Ladikos, T. Reichl, N. Navab Image-based tracking of the teeth for orthodontic augmented reality Proceedings of the 15th International Conference on Medical Image Computing and Computer Assisted Interventions (MICCAI), Nice, France, October 2012 (bib)
2011
	W. Wein, A. Ladikos Detecting Patient Motion in Projection Space for Cone-beam Computed Tomography Medical Image Computing and Computer-Assisted Intervention (MICCAI 2011), Toronto, Canada, September 2011 (bib)
	W. Wein, A. Ladikos, A. Baumgartner Self-calibration of geometric and radiometric parameters for cone-beam computed tomography 11th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, July 11-15 2011, Potsdam, Germany. (bib)
2010
	A. Ladikos, E. Boyer, N. Navab, S. Ilic Region Graphs for Organizing Image Collections ECCV Workshop on Reconstruction and Modeling of Large-Scale 3D Virtual Environments Workshop, September 2010 , Crete, Greece. (bib)
	A. Ladikos, C. Cagniart, R. Gothbi, M. Reiser, N. Navab Estimating Radiation Exposure in Interventional Environments Medical Image Computing and Computer-Assisted Intervention (MICCAI), September 2010 , Beijing, China. (bib)
2009
	A. Ladikos, N. Navab Real-Time 3D Reconstruction for Occlusion-aware Interactions in Mixed Reality 5th International Symposium on Visual Computing (ISVC), Las Vegs, Nevada, USA, Nov 30-Dec 2 2009. (bib)
	A. Ladikos, S. Ilic, N. Navab Spectral Camera Clustering ICCV Workshop on Emergent Issues in Large Amounts of Visual Data, Kyoto, Japan, Oct 4 2009. (bib)
	A. Bigdelou, A. Ladikos, N. Navab Incremental Visual Hull Reconstruction British Machine Vision Conference (BMVC), London (UK), September 7-10, 2009 (bib)
2008
	A. Ladikos, S. Benhimane, N. Navab High Performance Model-Based Object Detection and Tracking Computer Vision and Computer Graphics. Theory and Applications, Communications in Computer and Information Science, Vol. 21, Springer, 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)
	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)
	A. Bigdelou, A. Ladikos, N. Navab Shape from Silhouette in Dynamic Scenes Technical Report at Technical University of Munich (TUM), Munich (DE), August 15, 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)
	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)
2007
	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)
	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
	G. Panin, A. Ladikos, A. Knoll An Efficient and Robust Real-Time Contour Tracking System IEEE International Conference on Computer Vision Systems, New York, USA, January 2006. (bib)

Teaching

Summer Term 2010

Summer Term 2008

Summer Term 2007

• Praktikum 3D Computer Vision for Special Effects

Student Projects

Finished

• Image Segmentation for Occupancy Map Reconstruction , Master Thesis by Nuno Barreiro (2007/10/07)
• Camera Calibration for a Multi-Camera Environment, IDP by Martin Dummer (18.10.2007)