关键词: 边缘线, 条形码, 条形码定位, 阈值, 大津法, 直线检测

Abstract: Concerning the problems of recognizing bar code using image processing method, an effective and rapid algorithm was proposed to localize bar code through extracting edge lines. In this algorithm, a threshold value was obtained firstly by Otsu binary method from the original gray-level image. Pixels with gray values smaller than the threshold value were considered. The edge lines were extracted by sequential interlaced scanning in both row and column directions. Then the whole image was divided into strips of the same size. A starting strip was determined according to the position of the center point and the number of edge points distributed in strips. In starting strip, lines were detected by using edge points in the bottom of small ladder of a digital line, and angles of these lines were computed. Simulation compared the effect and running time of Sobel edge detector, Hough transformation, and the proposed algorithm. And the results prove the validity, rapidity and reliability of the proposed algorithm.

Key words: edge line, bar code, bar code localization, threshold, Otsu method, line detection