结构光条纹中心位置的精确检测是影响结构光系统精度的关键问题之一。提出一种多步骤的鲁棒性提取方法, 首先采用自适应阈值法剔除噪声点, 然后采用光条膨胀和细化方法, 得到初始的中心点, 并利用此初始中心点的梯度, 得到光条法线方向。最后, 在法线方向求取灰度重心, 得到光条亚像素中心线。该方法应用在基于线结构光检测原理的隧道轮廓变形监测装置中, 实验结果表明, 能准确提取光条纹中心。

Detecting light stripe center position accurately has critical consequences for the accuracy of the structured light measurement system. A robust method which extracts the light stripe center by multi step is proposed. Firstly, the noise points are moved by adaptive thresholds. Then, the initial centers of light stripes are obtained using expansion and thinning algorithm. After that, those initial centers’ normal direction can be gained with their gradient. At last, the sub-pixel center line of structured light is obtained by computing the gray-gravity along the stripe’s normal direction. The method applied to a tunnel contour deformation detection system which measuring principle is linear structured light. The test results showed that the method can accurately extract the center line.