PDF417作为一种广泛应用的二维条码，其检测定位成为条码识别过程中的关键，而复杂背景下条码的定位技术目前还不够完善。本文针对这一问题进行了研究，提出了一种基于数学形态学运算和Canny边缘检测的定位算法，并在此基础上作区域精确化处理，实现了条码的准确定位。实验结果表明，该方法能够有效提取出各种低对比度、边缘模糊、倾斜、商标干扰等复杂背景下的条码图像。

PDF417 is one of the widely used twodimensional barcodes, and the detection and location of its barcode area becomes a critical issue in the recognition process. While the location technique under the complicated background is far more than perfect now.We study this problem in this paper. Based on this, an algorithm based on mathematical morphology operations and the Canny marginal detection is proposed, afterwards, some local precise work is done to achieve the accurate location of the barcode area. The experimental results show that the method can effectively recognize the PDF417 barcode under various complex backgrounds, such as low contradistinction, blurred edges, incline and logo interference.