Research On Encoding And Decoding Technology Of Two-Dimensional Character Barcode

With the development of 3G technology, two dimensional barcode has widely been used on mobile terminals, and has played a significant role in real-time and economic consumption. On one hand, material resource waste is reduced. On the other hand, e-ticket ensures real-time and convenience. However, given the current wireless network bandwidth, multimedia receive rate of mobile terminal and image display requirements of the terminal adapter, etc, these constraints make the study of the two dimensional character barcode possible , and we promote core codec technology oriented short message.Based on the traditional encoding and decoding standards of two-dimensional white and black barcode, the encoding and decoding rules of two-dimensional character barcode is designed and implemented. The error correcting code is added to the character code, using Reed-Solomon algorithm. After adding error correcting codewords to the data codewords, we end up encoding with the symbolic procedure, and generate characters matrix. The character code has changed the format of the traditional two-dimensional barcode and replaced the character matrix code with graphic code.For the design of encoding schemes, we mainly researched the schemes of Data Matrix code and QR code, and analyzed the coding character sets and encoding rules of various schemes. Based on that, the two-dimensional character code, short for character code has designed 5 encoding schemes, and has implemented. In addition, there has intersect for different coding schemes, so we should consider the overall length of the whole data information, especially to the characters of intersects. Based on that, we have adopted the branch and bound algorithm for scheme selection to optimize the overall data encoding rather than some of the character encoding best. The codec of the error correcting code also used Reed-Solomon algorithm, which is used in Data Matrix code and QR code. In this paper, we made a detailed introduction to the principle and implementation of the error correcting code and designed two error correcting code encoding of different fields in encoding procedure of two-dimensional character barcode. The first one is in GF (28) field and it is encoding for data codeword to help checking character identification error which is generated by symbolic identification. The second one is in GF(23) field, which is to the version number and data scale id, and the error correcting code is to prevent low error rate of the version number and data scale id of the character code occurred in character identification step and not result in restore failure.The symbolic procedure of the character code includes the transmission of the codeword flow and binary flow, the conversion of the binary bit-stream and symbol characters, the error correcting code of the version number and data scale id and conversion of its codeword flow and the symbol characters. Meanwhile, the designing of symbol structure is the basis of symbolic procedure, and we have detailed described in this article.About the decoding of the character code, we firstly identify the character matrix and stored the result string. Secondly, we followed the decoding process of the character code to make the string conversion and error correcting decoding work. In this paper, we assumed some identification errors, and then followed the algorithm process to find errors and correct them, finally output decoding result figure.Experiments show that character code is a breakthrough to application of two-dimensional barcode combined with mobile terminal, which makes the character matrix replace with graphic barcode. And the research has played a significant role in diversification of two-dimensional barcode.