Dimensional control of metallic objects by artificial vision: contributionto lighting condition studies

We present an original method that enables real time automatic dimensional control of defects on metallic objects. The method is based on the theoreti cal and experimental study of light reflection mechanisms that can be seen as a function of the surface roughness and of the light source size. We sho w that it is possible to reconstruct the profile of an object from a single gray level image. An industrial application enables us to validate our res ults. Finally, an error computation fixes the limits of our method and enab les us to better understand illumination problems, (C) 1999 Society of Phot o-Optical Instrumentation Engineers.