Details
| Original language | English |
|---|---|
| Title of host publication | Automated Visual Inspection and Machine Vision IV |
| Editors | Jurgen Beyerer, Michael Heizmann |
| Publisher | SPIE |
| Number of pages | 11 |
| ISBN (electronic) | 9781510644083 |
| Publication status | Published - 20 Jun 2021 |
| Event | SPIE Optical Metrology - Online Duration: 21 Jun 2021 → 25 Jun 2021 https://spie.org/conferences-and-exhibitions/optical-metrology?SSO=1 |
Publication series
| Name | Proceedings of SPIE - The International Society for Optical Engineering |
|---|---|
| Volume | 11787 |
| ISSN (Print) | 0277-786X |
| ISSN (electronic) | 1996-756X |
Abstract
For the automated optical inspection of manufactured components with complex geometries or highly reflective surfaces, a suitable selection of measurement poses and the associated planning of the measurement trajectory is crucial. This is especially important for active triangulation measurement methods like fringe projection. Due to complex measurement object geometries or poor alignment of the measuring system the influence of multiple reflections can potentially lead to incorrect or incomplete 3-D reconstruction of the specimen surface. This paper introduces a simulative GPU-based inverse ray tracing approach to identify low-reflection measurement poses for active optical measurement systems. Starting from the virtual camera origin, rays are emitted from each camera pixel and the reflection at the measurement objects surface is calculated using the TorrenceSparrow BRDF. With an additional approach based on Whitted raytracing, the influence of multiple reflections and the reflection depth on the rendered camera image is taken into account. By calculating the summed reflection depth of each rendered measurement sequence, a height map of the reflection frequency distribution is created. By sampling a predefined surface point on the path of a limited sphere, the comparability of possible measurement poses is achieved. Thus, local minima can be identified and the poses with the lowest reflection influence can be selected to perform a suitable trajectory planning. This a priori knowledge can also be transferred into application and used for the estimation of image areas, which captured multiple reflections. Thus for these areas specific masks are generated and can be applied in real measurements to reconstruct multiple reflection free surfaces.
Keywords
- Inverse ray tracing, Multiple reflections, Optical measurement, Ray tracing, Reflection prediction
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
- Computer Science(all)
- Computer Science Applications
- Mathematics(all)
- Applied Mathematics
- Engineering(all)
- Electrical and Electronic Engineering
Cite this
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- Apa
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- BibTeX
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Automated Visual Inspection and Machine Vision IV. ed. / Jurgen Beyerer; Michael Heizmann. SPIE, 2021. 117870B (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 11787).
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research
, 21 Jun 2021. https://doi.org/10.1117/12.2592565
}
TY - GEN
T1 - A GPU-based ray tracing approach for the prediction of multireflections on measurement objects and the a priori estimation of low-reflection measurement poses
AU - Middendorf, Philipp
AU - Kern, Pascal
AU - Melchert, Nils Frederik
AU - Kästner, Markus
AU - Reithmeier, Eduard
PY - 2021/6/20
Y1 - 2021/6/20
N2 - For the automated optical inspection of manufactured components with complex geometries or highly reflective surfaces, a suitable selection of measurement poses and the associated planning of the measurement trajectory is crucial. This is especially important for active triangulation measurement methods like fringe projection. Due to complex measurement object geometries or poor alignment of the measuring system the influence of multiple reflections can potentially lead to incorrect or incomplete 3-D reconstruction of the specimen surface. This paper introduces a simulative GPU-based inverse ray tracing approach to identify low-reflection measurement poses for active optical measurement systems. Starting from the virtual camera origin, rays are emitted from each camera pixel and the reflection at the measurement objects surface is calculated using the TorrenceSparrow BRDF. With an additional approach based on Whitted raytracing, the influence of multiple reflections and the reflection depth on the rendered camera image is taken into account. By calculating the summed reflection depth of each rendered measurement sequence, a height map of the reflection frequency distribution is created. By sampling a predefined surface point on the path of a limited sphere, the comparability of possible measurement poses is achieved. Thus, local minima can be identified and the poses with the lowest reflection influence can be selected to perform a suitable trajectory planning. This a priori knowledge can also be transferred into application and used for the estimation of image areas, which captured multiple reflections. Thus for these areas specific masks are generated and can be applied in real measurements to reconstruct multiple reflection free surfaces.
AB - For the automated optical inspection of manufactured components with complex geometries or highly reflective surfaces, a suitable selection of measurement poses and the associated planning of the measurement trajectory is crucial. This is especially important for active triangulation measurement methods like fringe projection. Due to complex measurement object geometries or poor alignment of the measuring system the influence of multiple reflections can potentially lead to incorrect or incomplete 3-D reconstruction of the specimen surface. This paper introduces a simulative GPU-based inverse ray tracing approach to identify low-reflection measurement poses for active optical measurement systems. Starting from the virtual camera origin, rays are emitted from each camera pixel and the reflection at the measurement objects surface is calculated using the TorrenceSparrow BRDF. With an additional approach based on Whitted raytracing, the influence of multiple reflections and the reflection depth on the rendered camera image is taken into account. By calculating the summed reflection depth of each rendered measurement sequence, a height map of the reflection frequency distribution is created. By sampling a predefined surface point on the path of a limited sphere, the comparability of possible measurement poses is achieved. Thus, local minima can be identified and the poses with the lowest reflection influence can be selected to perform a suitable trajectory planning. This a priori knowledge can also be transferred into application and used for the estimation of image areas, which captured multiple reflections. Thus for these areas specific masks are generated and can be applied in real measurements to reconstruct multiple reflection free surfaces.
KW - Inverse ray tracing
KW - Multiple reflections
KW - Optical measurement
KW - Ray tracing
KW - Reflection prediction
UR - http://www.scopus.com/inward/record.url?scp=85109209609&partnerID=8YFLogxK
U2 - 10.1117/12.2592565
DO - 10.1117/12.2592565
M3 - Conference contribution
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Automated Visual Inspection and Machine Vision IV
A2 - Beyerer, Jurgen
A2 - Heizmann, Michael
PB - SPIE
T2 - SPIE Optical Metrology<br/>
Y2 - 21 June 2021 through 25 June 2021
ER -