A lighting characterisation by a reliable method. Application to defect detection by artificial vision in industrial field

This paper presents a reliable method which allows comparison of several lighting systems with respect to their capabilities of bringing out defects. This study has been led on textured industrial parts on which four types of defect have to be detected: smooth surfaces, bumps, lack of material and hollows knocked surfaces. The aim is to determine the best lighting among various experimental sets. This method has two stages: the first one is a definition of a pertinent attribute vector for which components are defect sensitive; in the second, discrimination power of this vector is computed and compared under various illumination. This method ensures a well-suited illumination in numerous applications in defects detection