Research activities of Christian Wöhler
Short scientific CV
Overview of research activities in the Image Analysis Group at TU Dortmund (since April 2010)
(examples also include previous research work at Daimler AG, Group Research
and Advanced Engineering)
- Image-based 3D reconstruction methods for industrial inspection and metrology
3D reconstruction of a raw forged iron surface using a combination
of shape from shading and fringe projection based active range scanning (lateral
resolution is 0.042 mm per pixel) (from Herbort et al., ICIP 2011).
3D reconstruction of a raw forged iron surface based on a
combined analysis of stereo, intensity, and polarisation features (top)
and relying on monocular photopolarimetric features alone (bottom, a pixel
corresponds to 0.30 mm) (from Wöhler and d'Angelo (2009),
International Journal of Computer Vision 81;
d'Angelo and Wöhler (2008), ISPRS Journal of Photogrammetry and Remote
Sensing 63).
3D pose estimation of industrial parts (from von Bank et
al., DAGM 2003).
- Methods for 3D object recognition, trajectory classification, and action recognition for robotics and advanced driver assistance systems
Recognition of working actions based on a non-stationary
HMM framework. Top: Spatio-temporal 3D pose estimation of the hand-forearm
limb with the Shape Flow algorithm. Bottom: Results of action recognition.
Blue: transfer motion; red: screw_1; black: screw_2; green: clean; ochre:
plug; white: unknown action; GT: ground truth (from Hahn et al., HCRS 2009).
Recognition of working actions and long-term motion
prediction by classification of trajectories for human-robot
interaction (from Hahn et al., ICVS 2008).
Spatio-temporal 3D pose estimation of the hand-forearm
limb for human-robot interaction with the Shape Flow algorithm (from Hahn
et al., ICPR 2008).
Spatio-temporal 3D pose estimation of the hand-forearm limb
for human-robot interaction (from Barrois and Wöhler, ICVS 2008).
3D tracking of the hand-forearm limb and the head-shoulder
contour for human-robot interaction (from Hahn et al., 3DIM
2007, Oldenburger 3D-Tage 2009).
Motion prediction system based on a low-dimensional manifold
constructed in a high-dimensional feature space representing the vehicle
trajectories using unsupervised kernel regression (Hermes et al., Dortmunder
Auto-Tag 2011).
Recognition and prediction of a situation involving two vehicles
turning left at a road intersection. The true future trajectories are denoted by
dashed lines, while the solid lines correspond to the motion hypotheses of the
vehicles (from Käfer et al., ICRA 2010).
Long-term trajectory prediction of vehicles based on
multiple hypotheses (from Hermes et al., Oldenburger 3D-Tage
2009, IV 2009).
Segmentation and 3D pose estimation of vehicles based
on stereo image analysis and optical flow estimation (from Barrois et al., IV 2009).
- Pattern recognition methods
Detection of US traffic signs using resource optimised
cascaded perceptron classifiers (from Staudenmaier et al., CI 2010).
Real-world (left) and synthetically generated (right)
training samples for traffic sign recognition
(from Hoessler et al., ICVS 2007).
- Methods for image-based 3D reconstruction and analysis of multispectral data for remote sensing applications
Shaded DEM of high lateral resolution of the eastern part of the lunar
crater Alphonsus (left) and of the lunar crater Menelaus (right), obtained based on a
photometric approach using Chandrayaan-1 M3 imagery in combination with LOLA data
(from Herbort et al., ICIP 2011 and Grumpe and Wöhler, ISPA 2011,
respectively).
Result of automatic lunar crater detection using a DEM of high
lateral resolution obtained based on a photometric approach using Chandrayaan-1 M3
imagery in combination with LOLA data. Green: previous LU60645GT catalogue; yellow:
additionally detected craters (from Salamunićcar et al., ISPA 2011).
Global lunar petrographic map, displaying the relative abundance
of the three most important lunar mineral types. Red channel: mare basalt; green
channel: Mg-rich rock; blue channel: ferrous anorthosite (from Wöhler et al. (2011),
Planetary and Space Science 59).
Left: DEM of the lunar volcanic dome Cauchy ω
(from Wöhler et al. (2006), Icarus 183). Right: DEM of the northern half of
the lunar crater Kepler, obtained based on a combined structure from motion and
shape from shading analysis of a sequence of the Smart-1 AMIE camera
(from d'Angelo and Wöhler (2008), ISPRS Journal of Photogrammetry
and Remote Sensing 63).
For detailed information see list of publications.
Download of image sequences and ground
truth data
A result of technology transfer: SafetyEYE
A research project for which my former colleague Dr. Lars Krüger and I were
responsible at Daimler AG, Group Research and Advanced Engineering, has led to the
development of the vision-based SafetyEYE system for three-dimensional surveillance
of working areas in industrial production. This system has been created
in cooperation between Daimler and the company Pilz GmbH & Co. KG,
a specialist for safe automation.
SafetyEYE's trinocular camera sensor
General information about the functionality of SafetyEYE (cf. published press material):
The SafetyEYE system consists of three calibrated cameras which monitor
the protection area around a machine, e. g. an industrial robot, and two
high-performance industrial PCs. The implemented stereoscopic algorithms
determine the three-dimensional structure of the scene being surveyed.
As soon as a potentially hazardous situation is about to occur, the system
initiates the protective measures necessary to prevent an accident, either
by slowing down or by stopping the machine. An important advantage of the
SafetyEYE system is the fact that it can be installed quickly and efficiently.
While setting up a traditional safety system consisting of several components
such as metal fences, light barriers, and laser scanners may take as long as
one day, only a few hours are needed to configure SafetyEYE's three-dimensional
protection areas. For the future, it is intended to increase the system
capabilities towards a distinction between persons and objects. This will
be a step towards collaborative working environments in which persons and
machines are able to work simultaneously on the same workpiece.
SafetyEYE has received the Automation Award 2006 as the
most outstanding product presented on the SPS Drives technology fair in
Nürnberg 2006 along with further awards (GIT Sicherheit Award 2007,
ISA Award 2007, Electrical Industry Awards 2007, ETOP Innovation Award).
It is is among the five products nominated for the Hermes Award 2007 and has
been nominated for the Deutscher Arbeitsschutzpreis.
Further details about the SafetyEYE system are given in the DaimlerChrysler Hightech
Report 2/2006 and at eMercedesBenz). For further information, see the
SafetyEYE product website featuring an
illustrative
video, and the website of the system supplier
Pilz GmbH & Co. KG.
Further activities
- Member of the editorial board of the Springer journal 3D Research,
editor of the topical
issue "3D Computer Vision" (September 2010)
- Reviewer for the journals Pattern Recognition Letters,
Image and Vision Computing, Earth and Planetary Science Letters, and Planetary and Space Science
- Co-organiser of the special session "Image Processing and Analysis
in Lunar and Planetary Science" of the 7th
International Symposium on Image and Signal Processing and Analysis (ISPA 2011),
Dubrovnik, Croatia, September 4-6, 2011
- Member of the programme committee of the
International Conference on Computer
Vision Theory and Applications (VISAPP) 2011 and 2012
- Co-organiser of the symposium Oldenburger 3D-Tage 2009
- Member of the programme committee of the 2nd Workshop
Robot
Vision 2008, Auckland, New Zealand, February 18-20, 2008
- Member of the programme committee of the
International Conference on Computer Vision
Systems (ICVS) 2008, Santorini, Greece, May 12-14, 2008
- Member of the programme committee, exhibition and industrial
relations chair of the International
Conference on Computer Vision Systems (ICVS) 2007, Bielefeld, Germany,
March 21-24, 2007
- Organisation of the workshop "Camera Calibration Methods for
Computer Vision Systems (CCMVS 2007)" in conjunction with ICVS 2007
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