Mr. Thorsten Bothe Profile

Thorsten Bothe

at Bremer Institut für Angewandte Strahltechnik

SPIE Involvement:

Author

Publications (17)

Proceedings Article | 2 August 2010 Paper

Optical metrology and optical non-destructive testing from the perspective of object characteristics

Ralf Bergmann, T. Bothe, C. Falldorf, P. Huke, M. Kalms, C. von Kopylow

Proceedings Volume 7791, 779102 (2010) https://doi.org/10.1117/12.862266

KEYWORDS: Nondestructive evaluation, Ultrasonography, Shearography, Optical metrology, Reflectometry, Reflection, Pulsed laser operation, Interferometry, Mirrors, Phase measurement

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Proceedings Article | 21 August 2009 Paper

Sub-nanometer resolution for the inspection of reflective surfaces using white light

Werner Jüptner, Thorsten Bothe

Proceedings Volume 7405, 740502 (2009) https://doi.org/10.1117/12.838373

KEYWORDS: Mirrors, Reflection, Cameras, Image processing, Imaging systems, Reflectivity, Interferometers, Silicon, Phase measurement, Phase shifting

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Proceedings Article | 7 March 2006 Paper

High-resolution measurement of extended technical surfaces with scalable topometry

Wolfgang Osten, Daniel Kayser, Thorsten Bothe, Werner Jueptner

Proceedings Volume 4101, (2006) https://doi.org/10.1117/12.498445

KEYWORDS: Fractal analysis, Sensors, Inspection, Image resolution, Feature extraction, Image sensors, Ceramics, Image segmentation, Shape analysis, Tolerancing

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Proceedings Article | 17 November 2005 Paper

Integrated quality assurance for assembly and testing of complex structures

Christoph von Kopylow, Thorsten Bothe, Frank Elandaloussi, Michael Kalms, Werner Jüptner

Proceedings Volume 5999, 59990L (2005) https://doi.org/10.1117/12.630726

KEYWORDS: Cameras, Reflection, Manufacturing, Inspection, Shearography, Distance measurement, Stereoscopic cameras, Imaging systems, Projection systems, Lamps

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SPIE Journal Paper | 1 October 2004

Scaled topometry in a multisensor approach

Daniel Kayser, Thorsten Bothe, Wolfgang Osten

OE, Vol. 43, Issue 10, (October 2004) https://doi.org/10.1117/12.10.1117/1.1788690

KEYWORDS: Fractal analysis, Sensors, Projection systems, Wavelets, Inspection, Cameras, Detection and tracking algorithms, Tolerancing, Optical engineering, Image resolution

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Proceedings Article | 10 September 2004 Paper

Evaluation methods for gradient measurement techniques

Wansong Li, Thorsten Bothe, Christoph von Kopylow, Werner Juptner

Proceedings Volume 5457, (2004) https://doi.org/10.1117/12.546002

KEYWORDS: Shearography, 3D metrology, Fourier transforms, Reflection, Feature extraction, Data integration, Optical metrology, Wavefront sensors, Sensors, Data processing

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Proceedings Article | 10 September 2004 Paper

High-resolution 3D shape measurement on specular surfaces by fringe reflection

Thorsten Bothe, Wansong Li, Christoph von Kopylow, Werner Juptner

Proceedings Volume 5457, (2004) https://doi.org/10.1117/12.545987

KEYWORDS: Reflection, Cameras, 3D metrology, Mirrors, Calibration, Particles, Image resolution, Imaging systems, Inspection, Error analysis

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SPIE Journal Paper | 1 February 2004

Accurate procedure for the calibration of a structured light system

Ricardo Legarda-Sáenz, Thorsten Bothe, Werner Jüptner

OE, Vol. 43, Issue 02, (February 2004) https://doi.org/10.1117/12.10.1117/1.1635373

KEYWORDS: Calibration, Laser sintering, Projection systems, Cameras, 3D modeling, Error analysis, Mathematical modeling, Instrument modeling, 3D acquisition, Structured light

Proceedings Article | 30 May 2003 Paper

Applications of inverse pattern projection

Wansong Li, Thorsten Bothe, Michael Kalms, Christoph von Kopylow, Werner Jueptner

Proceedings Volume 5144, (2003) https://doi.org/10.1117/12.508367

KEYWORDS: Cameras, Modulation, Phase shift keying, Projection systems, Inspection, Augmented reality, 3D metrology, Phase measurement, Image processing, Phase shifting

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Fast and robust 3D quality control as well as fast deformation measurement is of particular importance for industrial inspection. Additionally a direct response about measured properties is desired. Therefore, robust optical techniques are needed which use as few images as possible for measurement and visualize results in an efficient way. One promising technique for this aim is the inverse pattern projection which has the following advantages: The technique codes the information of a preceding measurement into the projected inverse pattern. Thus, it is possible to do differential measurements using only one camera frame for each state. Additionally, the results are optimized straight fringes for sampling which are independent of the object curvature. The hardware needs are low as just a programmable projector and a standard camera are necessary. The basic idea of inverse pattern projection, necessary algorithms and found optimizations are demonstrated, roughly. Evaluation techniques were found to preserve a high quality phase measurement under imperfect conditions. The different application fields can be sorted out by the type of pattern used for inverse projection. We select two main topics for presentation. One is the incremental (one image per state) deformation measurement which is a promising technique for high speed deformation measurements. A video series of a wavering flag with projected inverse pattern was evaluated to show the complete deformation series. The other application is the optical feature marking (augmented reality) that allows to map any measured result directly onto the object under investigation. Any properties can be visualized directly on the object’s surface which makes inspections easier than with use of a separated indicating device. The general ability to straighten any kind of information on 3D surfaces is shown while preserving an exact mapping of camera image and object parts. In many cases this supersedes an additional monitor to view results and allows an operator to investigate results on the object, directly.

Proceedings Article | 30 May 2003 Paper

Three-dimensional camera

Thorsten Bothe, Achim Gesierich, Ricardo Legarda-Saenz, Werner Jueptner

Proceedings Volume 5144, (2003) https://doi.org/10.1117/12.501959

KEYWORDS: Calibration, Stereoscopic cameras, Cameras, 3D metrology, Projection systems, Imaging systems, 3D modeling, Phase measurement, LCDs, Distance measurement

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Industrial- and multimedia applications need cost effective, compact and flexible 3D profiling instruments. In the talk we will show the principle of, applications for and results from a new miniaturized 3-D profiling system for macroscopic scenes. The system uses a compact housing and is usable like a camera with minimum stabilization like a tripod. The system is based on common fringe projection technique. Camera and projector are assembled with parallel optical axes having coplanar projection and imaging plane. Their axes distance is comparable to the human eyes distance altogether giving a complete system of 21x20x11 cm size and allowing to measure high gradient objects like the interior of tubes. The fringe projector uses a LCD which enables fast and flexible pattern projection. Camera and projector have a short focal length and a high system aperture as well as a large depth of focus. Thus, objects can be measured from a shorter distance compared to common systems (e.g. 1 m sized objects in 80 cm distance). Actually, objects with diameters up to 4 m can be profiled because the set-up allows working with completely opened aperture combined with bright lamps giving a big amount of available light and a high Signal to Noise Ratio. Normally a small basis has the disadvantage of reduced sensitivity. We investigated in methods to compensate the reduced sensitivity via setup and enhanced evaluation methods. For measurement we use synthetic wavelengths. The developed algorithms are completely adaptable concerning the users needs of speed and accuracy. The 3D camera is built from low cost components, robust, nearly handheld and delivers insights also into difficult technical objects like tubes and inside volumes. Besides the realized high resolution phase measurement the system calibration is an important task for usability. While calibrating with common photogrammetric models (which are typically used for actual fringe projection systems) problems were found that originate from the short focal length and the extreme opening angle of the system as well as the large depth of focus. The actual calibration method is outlined and current problems are shown. An improved calibration of the system is discussed for improved results in future.

Proceedings Article | 27 May 2003 Paper

Object-adapted inverse pattern projection: generation, evaluation, and applications

Thorsten Bothe, Wansong Li, Christoph von Kopylow, Werner Juptner

Proceedings Volume 4933, (2003) https://doi.org/10.1117/12.516653

KEYWORDS: Cameras, Augmented reality, Inspection, Projection systems, 3D metrology, Phase measurement, Image processing, Visualization, Modulation, Video

Read Abstract +

Fast and robust 3D quality control as well as fast deformation measurement is of particular importance for industrial inspection. Additionally a direct response about measured properties is desired. Therefore, robust optical techniques are needed which use as few images as possible for measurement and visualize results in an efficient way. One promising technique for this aim is the inverse pattern projection which has the following advantages: The technique codes the information of a preceding measurement into the projected inverse pattern. Thus, it is possible to do differential measurements using only one camera frame for each state. Additionally, the results are optimized straight fringes for sampling which are independent of the object curvature. The ability to use any image for inverse projection enables the use for augmented reality, i.e. any properties can be visualized directly on the object's surface which makes inspections easier than with use of a separated indicating device. The hardware needs are low as just a programmable projector and a standard camera are necessary. The basic idea of inverse pattern projection, necessary algorithms ane found optimizations are demonstrated, roughly. Evaluation techniques were found to preserve a high quality phase measurement under imperfect conditions. The different application fields can be sorted out by the type of pattern used for inverse projection. We select two main topics for presentation. One is the incremental (one image per state) deformation measurement which is a promising technique for high speed deformation measurements. A video series of a wavering flag with projected inverse pattern was evaluated to show the complete deformation series. The other application is the optical feature marking (augmented reality) that allows to map any measured result directly onto the object under investigation. The general ability to straighten any kind of information on 3D surfaces is shown while preserving an exact mapping of camera image and object parts. In many cases this supersedes an additional monitor to view results and allows an operator to investigate results on the object, directly.

Proceedings Article | 20 June 2002 Paper

Scaled multisensor inspection of extended surfaces for industrial quality control

Daniel Kayser, Thorsten Bothe, Wolfgang Osten

Proceedings Volume 4777, (2002) https://doi.org/10.1117/12.472225

KEYWORDS: Inspection, Sensors, Tolerancing, Fractal analysis, Wavelets, Data integration, Detection and tracking algorithms, Optical testing, Assembly tolerances, Process control

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Proceedings Article | 19 June 2002 Paper

Reverse engineering by fringe projection

Jan Burke, Thorsten Bothe, Wolfgang Osten, Cecil Hess

Proceedings Volume 4778, (2002) https://doi.org/10.1117/12.473547

KEYWORDS: Fringe analysis, Calibration, Cameras, Phase measurement, Computer aided design, Projection systems, Data modeling, Solid modeling, Reverse modeling, Reverse engineering

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Proceedings Article | 19 June 2002 Paper

Compact 3D camera

Thorsten Bothe, Wolfgang Osten, Achim Gesierich, Werner Jueptner

Proceedings Volume 4778, (2002) https://doi.org/10.1117/12.473573

KEYWORDS: LCDs, Cameras, Projection systems, Stereoscopic cameras, Objectives, Lamps, Polarizers, Phase measurement, Charge-coupled devices, CCD cameras

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Proceedings Article | 23 October 2001 Paper

Projection of structured light in object planes of varying depths for absolute 3D profiling in a triangulation setup

Klaus Koerner, Ulrich Droste, Robert Windecker, Matthias Fleischer, Hans Tiziani, Thorsten Bothe, Wolfgang Osten

Proceedings Volume 4398, (2001) https://doi.org/10.1117/12.445556

KEYWORDS: Signal detection, Modulation, Phase shift keying, LCDs, CCD cameras, Cameras, Imaging systems, Sensors, Calibration, 3D metrology

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Proceedings Article | 13 August 1999 Paper

Fault detection in gray-value images of surfaces on different scales

Daniel Kayser, Thorsten Bothe, Wolfgang Osten

Proceedings Volume 3744, (1999) https://doi.org/10.1117/12.357701

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Proceedings Article | 31 March 1998 Paper

Nondestructive testing and evaluation of historical monuments using thermography and electronic speckle pattern interferometry (ESPI)

Peter Meinlschmidt, Thorsten Bothe, Klaus Hinsch, Lutz Mehlhorn

Proceedings Volume 3396, (1998) https://doi.org/10.1117/12.301533

KEYWORDS: Thermography, Speckle pattern, Nondestructive evaluation, Interferometry, Cameras, Video, Temperature metrology, Reflection, Inspection, Climatology

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Showing 5 of 17 publications

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