Fast detection method of quick response code based on run-length coding

Quick response (QR) code, one of the two-dimensional barcodes, is now being widely used in all fields. The effectiveness of decoding, however, needs to be improved in real-time application. In most cases, the decoding procedure is time consuming, in which the detection of QR code plays an essential part. Therefore, this study proposes a fast detection method of QR code based on run-length coding: firstly, a novel approach is proposed to detect the minimum region containing position detection pattern (PDP) in QR code. Second, coordinates of central PDP in QR code are calculated by using run-length coding. The highlight in this step is the calculation, which utilises modified Knuth-Morris-Pratt algorithm. By this means, the computational complexity can be reduced tremendously. Finally, QR code can be detected successfully with the coordinates. The experimental results show that the proposed method is time saving and suitable for real-time application.