Structured light systems for dent recognition: Lessons learned

This paper describes the results from a feasibility analysis performed on two diierent structured light system designs and the image processing algorithms they require for dent detection and localization. The impact of each structured light system is analyzed in terms of their mechanical realization and the complexity of the image processing algorithms required for robust dent detection. The two design alternatives considered consist of projecting vertical or horizontal laser stripes on the drum surface. The rst alternative produces straight lines in the image plane and requires scanning the drum surface horizontally, whereas the second alternative produces conic curves on the camera plane and requires scanning the drum surface vertically. That is, the rst alternative favors image processing against mechanical realization while the second alternative favors mechanical realization against image processing. The results from simulated and real structured light systems are presented and their major advantages and disadvantages for dent detection are presented. The paper concludes with the lessons learned from experiments with real and simulated structured light system prototypes.