Recognition Technology And Application Of PDF417Bar Code

With the promotion of the applications of barcode technology, the demand levelof bar code technology inconstantly improving. Two-dimensional bar codetechnology is an emerging automatic identification technology which developed onthe base of computer technology and information technology that set of coding,printing, identification, data collection and processing, it is widely used because of itshigh density, strong error correction capability, as well as its safety and highconfidentiality. The dissertation regard the PDF417barcode as the research object,in-depth study of the two-dimensional bar code reading technology, design andimplementation of PDF417two-dimensional bar code applications in medicalinsurance card information management systems.Firstly, on the PDF417barcode encoding rules and encoding mode for detailedanalysis and research, summarizes the PDF417barcode generation principle, tointroduce code generation process by way of example, designed and implementedgeneration system of PDF417barcode by using VC++class library foundation.Secondly, this dissertation studied the pre-processing steps of PDF417barcodeimage, including gray-scale image, filtering noise, barcode tilt correction and imagebinarization, for barcode images often encounter uneven illumination backgroundcomplex cases, by analyzing and comparing the merits of traditional binary process,proposed binary process base on wavelet decomposition and OTSU. Using waveletanalysis estimate light distribution to eliminate the effects of uneven illumination,then using OTSU to binarize, a good solution caused by the background complexityor uneven illumination.Then, the dissertation gives picture decoding process of the PDF417barcode indetail, segmented single codeword of barcode, and get the cycle sequence of eachcodeword, then complete the decoding work. Based on the unique structuralcharacteristics of bar code, bar code images are divided rows and columns, usingprojection algorithm and waveform analysis is complete two-dimensional bar codeimage of a single word segmentation, the algorithm up to some extent, in addition tothe effects of noise pollution, improve the accuracy of identification bar code also reduces the computational error. After obtaining the code word, dissertation use RSerror correction code on the bar code information to correct the codeword error, studyencoding and decoding of RS error correction code in detail.Finally, according to applications of PDF417two-dimensional barcode in the medical field, designed the information management system of medicare card. The designed generate systems and recognition algorithms is applied to the management information management system of Medicare card, to achieve effectively manage information of health insurance card cardholder, widening the application field of two-dimensional barcode, laying the groundwork for applying research of the subsequent two-dimensional bar code technology.