基于法线引导的激光中心线提取方法  

Laser center-line extraction method based on normal guidance

作　　者：刘天赐 刘桂华[1] 胡莉[1] 黄会明[1] LIU Tianci;LIU Guihua;HU Li;HUANG Huiming(School of Information Engineering,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学信息工程学院,四川绵阳621010

出　　处：《应用光学》2023年第1期211-218,共8页Journal of Applied Optics

基　　金：四川省科技厅重点研发项目(2021YFG0380);四川省卫生和计划生育科研课题(17PJ207)。

摘　　要：在线结构光三维测量系统中,高精度激光条纹中心线提取是提高测量精度的关键。针对现有激光中心线存在提取精度不高、保留细节差等问题,提出了一种基于法线引导的激光中心线提取算法。该算法具体实现步骤为:首先,对图像进行预处理,结合边缘检测和几何中心法对激光线初步提取;然后,用主成分分析法(principal component analysis,PCA)求取其法线,在激光中心点处划分角度八邻域,通过法线角度引导搜寻有效点集;最后,利用灰度重心法对点集进行亚像素提取。实验结果表明:该算法均方根误差与灰度重心法相比提高了0.233 9像素,比Steger算法、方向模板法更好地保留了光条细节,可以更精确地提取光条中心,达到亚像素级的精度。In the line structured light three-dimensional measurement system, the high-precision laser stripe center-line extraction is the key to improve the measurement accuracy. Aiming at the existing laser center-line problems such as low extraction accuracy and poor retention of details, a laser center-line extraction algorithm based on normal guidance was proposed. The specific implementation steps of the algorithm were as follows:Firstly, the image was pre-processed, and the laser line was preliminarily extracted by combining edge detection and geometric center method. Then, the principal component analysis(PCA) was used to obtain its normal line, divided the angle eight neighborhood at the laser center point, and searched for the effective point set through the normal angle guidance. Finally, the gray centroid method was used to extract the sub-pixels from the point set. The experimental results show that the root mean square error of the algorithm is improved by 0.233 9 pixel compared with that of the gray centroid method, which can retain the light strip details better than the Steger algorithm and the directional template method, and can extract the light strip center more accurately and achieve the sub-pixel level accuracy.

关 键 词：线结构光 法线引导 几何中心 主成分分析 八邻域 灰度重心 

分 类 号：TN209[电子电信—物理电子学] TP391[自动化与计算机技术—计算机应用技术]