The Print Quality Inspection System Research And Development

With the continuous improvement of people's life, more and more print occupies the market, which meets the needs of customers with high quality and diversity. Production automatization has been come true in many influential print enterprises now. Then a problem comes out in the print field: That is how to detect the print defects more quickly and precisely. Traditional methods which detect print defects with human eyes can't achieve detection work well owing to the subjective aspects. With the development of computer technology, an automatic print quality detection using machine vision and digital image processing technology becomes feasible.Based on computer image processing technology and on the base of analysing and summarizing various print quality detection methods, the main techniques on print quality detection are presented in this thesis in detail. The thesis mainly consists of three parts. First, The constitution of print quality detection system and the holistic frame of system software and hardware is briefly presented. Then application of CCD camera and image collection grabber is systemicly analyzed. Third, on the base of introducing some basic theory about digital image processing and some programming design about image processing based on the VC++6.0 platform, various image processing algorithms of real-time and precise detection performance used in print quality detection system are presented in the thesis. The algorithms (or methods) are image preprocessing method, building method of template image, image match method, bug detection method and so on. They are the key part of the detection system. The results of theory analysis and experiments show that the methods brought out in the thesis are feasible and effective.