Two-dimension bar code and its coding and decoding method

Abstract

The present invention discloses a method for coding and decoding two-dimensional bar codes. The coding method comprises a data code word generating step, an error-correcting code word generating step, a main code pattern frame generating step and a code pattern image forming step through code word filling. The decoding method is that: a gray scale image of a code pattern is acquired through a digital photography mode; the gray value distribution of different pixels in the gray scale image is counted; a threshold value is determined; the gray scale image is converted into a binary image and an edge image is acquired; the four-corner coordinate of each macro block in the code pattern and the center coordinate of each unit module inside the macro blocks are calculated; the bit value stored by each unit module is determined so as to acquire a data code word matrix corresponding to the decoded code pattern; the data code word is read according to a correct center macro block and the code pattern direction; RS error-correcting algorithm is used to correct the errors in the code word according to a preset error-correcting grade; the data code word is output and recovered as a binary number.

Description

technical field [0001] The invention relates to a coding and decoding method of a two-dimensional barcode. Background technique [0002] A matrix QR code generally consists of three parts: a feature pattern area, a format information area, and a data code word area. Among them, the feature mode area guides the image recognition algorithm to identify the positioning code map, the format information area stores parameters describing the format of the code map and data error correction, and the data code word area stores data encoded by the error correction coding algorithm. If the characteristic mode area and the format information area are damaged to a certain extent, the code map cannot be recognized, so these two areas become the fatal area (vulnerable area) in the code map, reducing the reliability of the two-dimensional code . [0003] As shown in Figure 1, it is a schematic diagram of the PDF417 code structure. The vertical lines with different widths at the left and r...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is: to overcome the shortcomings of the existing two-dimensional barcode encoding method that the barcode obtained by the existing two-dimensional barcode encoding method is easily damaged, resulting in the inability to recognize the code map and the reliability, efficiency and accuracy of the decoding method are not high, and to provide an improved two-dimensional barcode Dimensional barcode and its encoding and decoding method

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