A low-cost inspection system for online defects assessment in satin glass

In this paper, the problem of detecting and measuring the defects of satin glass is investigated, and an in-line PC-based visual inspection system is proposed; this system is able to analyze the glass surface under inspection, to discover and classify its defects, and to assess the product quality. A working prototype of this system has been designed, built and tested to validate the proposed approach and to reproduce the real issues of an in-line quality control system. The developed prototype includes three subsystems: an array of several CMOS cameras, a controllable roller conveyor, and a PC-based image processing system that is also responsible for the control of the other subsystems. The detection of the defects is performed by means of Canny edge detection, with thresholds chosen according to some statistics of the images being processed. Currently, the prototype is under further development in cooperation with a specialized electronic industry.