Algorithms Research For Online Banknote’s Quality Inspection

With the rapid increase of paper production, the traditional ways to inspect thequality of the paper by people’s eyes can no longer meet the needs of the market, so akind of online banknote‘s quality inspection system based on machine vision comes intobeing. In modern banknote making enterprises, they try every effort to achieve thepromotion both in quality and production efficiency. And the three importantfoundations to achieve these goals are production automation, intelligent inspection andManagement Information-Based. This system will combine these three parts, comparingwith the traditional inspection by people’s eyes, it presents the technical advantages indealing with the image processing. It can be automatically inspect and analyze thequality of the products and then manage the information data.Online banknote‘s quality inspection system is very complicated large machinevision inspection equipment which integrated with optical, mechanical and electricalelements. It involves many technical areas such as image processing, machine vision,mathematical model, industrial test, optical imaging, and dynamic mechanical andelectrical control. The emerge of this kind of system can largely save the labor resources,it can also save the inspection cost and promote the production quality，at the sametime，it can improve the production speed and efficiency. Therefore， more and moreenterprises have faith in it and choose it. However, with the increase of the papermaking speed and its width, this kind of system will be endowed with higherexpectation. The operation of online inspection system encounters with somedifficulties，so it still need to be further studied and improved.This paper will be based on the project background and introduce the operation ofonline banknote‘s quality inspection system based on machine vision. It first introducessome related background and basic knowledge of the project, including the basic theory,general system design and imaging system design. Then it introduces the criticalalgorithm design of the online banknote’s quality inspection system in detail.Thecritical algorithm includes：image preprocessing algorithm, The paper district residuedetection algorithm design,the weak contrast of paper area wrinkle inspection, the basic principles of the watermark, the vague of watermark inspection algorithm and thewatermark contour extraction algorithm design, the edge of the sub-pixel searchpositioning of the safety line, safety line determination of the standard and the zebraDistrict residual point detection algorithm design. Finally, give analysis andimplementation on the critical online inspection algorithm and test the system.