QR Code as a High-Speed, Omni-Directional Recognizable 2D Barcode

In this paper, we discuss the applications of QR codes and their potential across various industries. As a high-speed, omni-directionally recognizable 2D barcode, QR codes have gained widespread adoption. However, several challenges may arise during QR code image recognition, including image noise interference, partial inclusion of QR codes within captured images, image tilt, and geometric distortion. To address these issues, we propose an enhanced median filtering method for noise removal, which implements an adaptive window size algorithm to better preserve edges while eliminating salt-and-pepper noise. We leverage QR code symbol characteristics—specifically the position detection patterns and timing patterns—for accurate localization and tilt correction through coordinate transformation and rotation algorithms. For images with mild distortion, we employ control point transformation combined with bilinear interpolation methods for geometric correction, ensuring pixel value continuity during image warping. Experimental verification confirms that our approach is straightforward yet effective, substantially improving the correct recognition rate of barcodes through optimized image preprocessing techniques.