Barcode is constitute by plurality of black bars and blank, the width of black bars are different, and these bars arranged in encoding rules for expression a group of information, graphics and identifier. It usually appear in our lives asbarcode labels.

May be barcode labels seems very simple just like many black lines printed on a paper, but the recognition principle of barcode is not simple. The barcode need to be complied according to certain rules so that can be change into meaningful information. In order to get the information, it is need two steeps, scanning and decoding.

The barcode labels are having a high reliability. The accuracy of reading a barcode is far more than manual records, 15000 characters just appear one error. Barcode has greater flexibility, the identification device and the relative position of the labels’ strip has the degree of freedom is much greater than the OCR( Optical Character Recognition). A barcode usually expression the information only by one-dimensional, on the same barcode, the information represented is continuous and the same, so even if the label has some shortcomings, you can still enter the correct information from the normal part.

Barcode labelsare data carrier. It plays an important role in the information transmission. If the barcode has a problem, the item’s information communication will be interrupted, so it is necessary to control the barcode’s quality effectively, make sure the bar code symbol in the supply chain can be properly read. Barcode detection is an effective tool to achieve this goal. Bar code detection target is to check whether the bar code symbol is able to play its due role.

The barcode inspection not only overcome the defects of traditional detection methods, but also has been developed to using the integrated bar code quality grading which called reflectivity curve analysis. Comprehensive grading method is based on scanning reflectivity curve.