Research And Implementation Of Barcode Identification System Facing Mobile Terminals

Barcode technology which was first invented in 1950 s, is incresingly used in business, medical industry, machinery manufacturing, financial business, logistics industry, warehousing etc in a worldwide range. Barcode technology is developing rapidly in recent years, especially the wide use of QR code, that makes barcode technology part of people’s life. At present, mature barcode identification equipment is available on the market, however with a drawback of single function.With the development of embedded hardware and software technology, intelligent mobile terminals began to develop rapidly, of which the smartphone is the fastest growing category. Barcode technology can provide data support for intelligent terminal easily. By different kinds of applications in intelligent terminals, the same device can be applied to a number of different scenarios.To combine barcode technology with the current rapid developing Internet applications, the subject of this thesis is based on barcode recognition system for mobile intelligent terminal. This thesis mainly studies one/two dimensional barcode decoding method, through image processing in the barcode location, to improve the effect of decoding the fuzzy, low resolution image. Based on intelligent mobile terminal technology, this thesis designs and implements a barcode identification system. This system is based on embedded Linux and open source operating system Android; with realized decoding library, a variety of decoding application can be ran to apply them in all variety of daily work. The main research is divided into four parts.The first part comes up with the barcode identification system. The framework of the system is divided into 3 layer: the application layer, the decoding middleware layer and the hardware layer. Application layer will differ according to different application scenarios and implement the business logic. Decoding middleware is the most important part which implements the hardware drivers, provides a common interface to the application layer, and does the operation in application layer shielding concrete hardware.Finally according to the needs of barcode recognition, hardware devices including a camera module, lights, lights, buzzer, buttons, etc are selected.The second part is the design and implementation of the driver. According to the different control interface of the hardware connection, analyseis are made in Linux GPIO, I2 C, PWM, V4L2 and SPI driver framework, and the corresponding hardware device drivers are implemented; An abstract access layer is implemented to provide the hardware operation-interface for the application layer.The third part is the research of decoding algorithm. The decoding algorithm is divided into two parts. One is to use image processing methods to improve the quality of barcode image, from the design of the barcode location, deblurring, lowering resolution, image rotation.Secondly, according to each type of barcode coding standards, the algorithm completes the design in image content character content vonvertion through the barcode image recognition.The fourth part is the test of bar code recognition system performance.Through tests of a variety of different angles, the performance of barcode recognition system realized in our work is determined and compared with the current mature barcode recognition devices on the market.