ARM-based PDF417 Two-dimensional Bar Code Recognition

With development of communication and computer technology, bar code technology came into being, it is one of automated identification technology. According to the binary encoding rule, some bars and spaces compose of the bar code figure. The scanner reads the figure and processes or decodes informations. Since bar code technology came forth, people have paid important attention to it. The bar code technology has abroad applied in transportations, bussiness, medical treatment, manufacturing, storage, postage fields and so on. The bar code technology has improved the speed of data collection and information processing, increased the work efficiency, and having made contribution for administrative scientification, informationization and modernization. Now one-dimensional bar codes are most widespread. But the information which one-dimensional bar codes stores is limited, this is also its most weakenss. It must depend on the external database. Without the database, one-dimensional bar codes can not have meanings. Two-dimensional bar codes overcome this weakness. It is high density and high information amounts bar codes on the one-dimensional bar code foundation. It can encode a large of information in a small area, is a full data file. It is an ideal method, which can store information on card and can be decoded by scanner.The topics adopted the popular embedded technology. S3C44B0X is used as the data collection terminal for the two-dimensional bar code PDF417 identifier. TheμC/OS-Ⅱoperating system embedded in the terminal which can divide the application into multi-task, simplify the application system software design, have the real-time control system, enhance reliability and stability of the system, the scalability of the system and continuation of product development at the same time.The PDF417 two-dimensional bar code image recognition is the issue's main task. First the computer gains the original two-dimensional bars code image by the scanner or the camera, then the image of PDF417 2D barcode is processed by the program on the PC. Then the image is further segmented to locate the single codeword image and it's recognized by the algorithm. The article improvements the barcode image preprocessing algorithm which can effectively remove the interference of noise and get the image positioning. The experimental results show that the performance of the system is good.