Quick recognition method of Data Matrix barcode
一种Data Matrix条码的快速识别方法*

In response to the real-time requirement of barcode identification from industrial assembly line, this paper put forward a quick recognition method of Data Matrix barcode. With shape parameter and circular shape as a rectangular feature,determined the location of Data Matrix barcode primarily. Using the function of distance angle for Data Matrix to mark the border of Data Matrix barcode,made an analysis by transfering the border of 2D barcode of Data Matrix to 1D waveform function. The first derivative was found for obtaining the boundary location as well as rotation angle. Employing boundary angle as the affine transformation angle,rotated the barcode to a standard location, data being extracted by grid method, and then decoded the barcode. After checking 400 pictures whose pixels in size were 640×480 containing Data Matrix barcode on PC, it came out that the time for average single barcode recognition was 12.06 ms, and the recognition rate was 99.22%. The quick recognition method is proved to be fast and accurate, able to meet the real-time and reliable requirement for industrial field.