一种正六边形检测方法的研究

提出了一种基于几何特征的正六边形检测方法。在简述Hough变换原理和正六边形特点的基础上，把正六边形的检测分解成直线和圆的检测，以及线段长度和直线夹角的计算。利用检测到的直线，在图像平面内建立直线方程，依据直线方程，计算相邻两条直线的夹角和交点，求出每条边的长度，同时检测6个交点是否均匀分布在同一圆周上。在螺栓头部正六边形检测实验中，角度测量误差为0.38%，边长测量误差为0.85%。结果表明，该方法是有效的，能准确地检测出图像中的正六边形。

Visual detection of regular hexagon

A vision detection method based on geometric characteristics to detect regular hexagon is proposed. Hough transform and the regular hexagon characteristics are briefly introduced, and the detection of regular hexagon is decomposed into the line detection，the circle detection, the calculation of the lengths of line segments and the angles between adjacent lines. Based on the detected line segments, the line equations are constructed in the image plane. The intersection points of adjacent lines and the angles between two adjacent lines are calculated by the constructed line equations. The length of every side of regular hexagon is obtained by computing the distance between the two adjacent intersection points. The circle detection method based on Hough transform is employed to inspect whether all intersection points locate at the same circumference. The detection experiment of hexagon bolt is carried out to illustrate the performance of the presented method. The measurement errors of angles and side lengths of regular hexagon are 0.38% and 0.85% respectively. The result shows that the method is valid and can detect regular hexagon in the image precisely.