Two-dimensional Bar Code (Data Matrix) Image Processing And Recognition

Two-dimensional (2D) Barcode solves the One-dimensional Barcode over-reliance on storage devices, its higher capacity, higher density, more powerful error-correction ability, higher security ability, so it plays an important role in the information automation field. Based on digital image processing and combined coding theory, two-dimensional matrix bar code is a symbol system processed automatically using image recognition technology. The Recognition Technology of 2D was more complex than that of one-dimensional barcode. For example, In the vertical direction, one-dimensional barcode is not store the information, and its height is used for easy recognition and partially offsetting printing defects or damage. Two-dimensional barcode stores the information. So, it was an important research field to recognize 2D fleetly and effectively.We will face the problem that comes from missing ink and ray uneven, and it difficult to identify the barcode. In this paper, we use the gray histogram processing to solve this problem.How to get the image value is an important part in image processing, By contrast Programming the maximum entropy image threshold segmentation and overlap threshold method. This paper use the flexibility of stronger, more efficient algorithms the overlap threshold method.To locate the barcode, getting the edge of barcode and locate the L, we use the Gauss Laplace operator. This method first smoothing the noise and then getting the edge, and we can get more accurate Border information.According to Hough transform, this paper gives the slope to a central point of computing to transform and computes the rotation angle, and the result is more efficient, more accurate calculation.The hardware of the system is composed of scanner, printer and computer. The software is using VC++ under contrasting a variety of image processing and recognition algorithm process.