Translator Disclaimer
4 April 2001 Dynamic lighting system for specular surface inspection
Author Affiliations +
Proceedings Volume 4301, Machine Vision Applications in Industrial Inspection IX; (2001)
Event: Photonics West 2001 - Electronic Imaging, 2001, San Jose, CA, United States
Specular surfaces inspection is a problem met frequently within the automatic control of metallic products. A tried technique to reveal the aspect defects is the imaging of the reflection of a structured lighting as Dark Field Illumination through the surface. In order to inspect the whole surface, an element of the lighting structure has to scan every part of the surface. In the case of important surface curvature gradients, entire scanning is not ensured if the object is moving in front of the static lighting. To overcome this limitation, an inverse process is proposed: the lighting structure is dynamic while the object is static. The scanning of the surface by the various lighting configurations enables the aspect control. A modeling of the surface to be inspected and defects to be detected is made. Inverse ray tracing is used to analyze the reflection of the lighting through the surface. This modeling enables to ensure the revealing of defects by respecting the chosen criteria of detection. A relation binding the physical size of defects and its size on the image is established. A metrological approach of the problem is then performed.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ralph Seulin, Fred Merienne, and Patrick Gorria "Dynamic lighting system for specular surface inspection", Proc. SPIE 4301, Machine Vision Applications in Industrial Inspection IX, (4 April 2001);

Back to Top