Research And Implementation Of PDF417 Barcode Encoding And Decoding Algorithm

One-dimensional barcode is widely used in modern packaging field, but it can no longer meet the packaging needs in several aspects such as transportation, capacity and expressing information, because of a good many of its limitations. The appearance of two-dimensional barcode solves these problems. it expresses information in both transverse and longitudinal two bearing at the same time, not only being able to express a great deal information within very minor area, which make it a absolute information carrier independence on data-base, but also expressing the Chinese character and image information. At the same time, the two-dimensional barcode adopts the advanced RS error correction code, which improves the read capability of barcode. It is a trend in packaging industry that widely applying two-dimensional barcode into the packing of products for the future. In the near years the two-dimensional barcode has carried out tentative applications in some fields in our country. However the research encounters greatly restricting, because the software platform which the applications based on is owned by several abroad companies. This research is about PDF417 barcode which is a representative stacked barcode among the two-dimensional barcode, designing the generative system of barcode with the correlative algorithm, and fulfilling decoding system, based on the VC++ 6.0 design platform.Firstly, the research studies the coding rule of the PDF417 barcode and designs related computer code algorithm, with making it programmed, and completes the coding part of the system software. Next, the coding and decoding principle of Reed-Solomon error-correcting code (RS code) is briefly introduced. According to thecoding and decoding principle in galois field GF(929), to analyze and study its practical application with emphasis in this topic. Then, the PDF417 barcode decoding process is analyzed and studied detailed according to the barcode coding principle, with the corresponding realization method designed, improving the design in theory aspect by using material example, at the same time programming the design method to complete the decoding part of the system. Finally, validated the system program in the practical application of image information aspect, by using the nonrepeatability and the randomicity characteristic of Julia mark shape artwork.