Coding principle and implementation of two-dimensional PDF417 bar code

PDF417 is a two-dimensional stacked bar code symbology capable of encoding over a kilobyte of data per label. Each symbol character is 17-module wide which always consists 4 bars and 4 spaces. This paper studies the coding principle of two-dimensional PDF417 bar code and completes the implementation of two-dimensional PDF417 bar code through the Microsoft Visual C++ 6.0 development environment. Not only introduces one of PDF417 primary features which is error detection and error correction, designs the process to achieve the value of the strike a sequence of characters, as well as the generation of bar code, such as the theoretical principles of each module, but also given the module in Visual C++ 6.0 in the achievement of specific procedures. The paper gives the result of simulation through c++ procedures.