基于调制度分析的有效测量区域自动分割算法  

Automatic segmentation algorithm for effective measurementregion based on modulation analysis

作　　者：吴昊 沈建新[1] 戴家隆[1,2] 殷飞 刘文良 WU Hao;SHEN Jianxin;DAI Jialong;YING Fei;LIU Wenliang(College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;AERO-APEX Intelligent Technologies Co Ltd,Nanjing 211100,China;Hanzhong Aircraft Branch of AVIC Aircraft Co Ltd,Hanzhong 723213,China)

机构地区：[1]南京航空航天大学机电学院,江苏南京210016 [2]江苏航鼎智能装备有限公司,江苏南京211100 [3]中航飞机股份有限公司汉中飞机分公司,陕西汉中723213

出　　处：《传感器与微系统》2022年第3期117-121,125,共6页Transducer and Microsystem Technologies

基　　金：国防重大项目培育基金资助项目(NP20200420);江苏省研究生科研与实践创新项目(KYCX180317);南京航空航天大学研究生创新计划项目(XCXJH20210510)。

摘　　要：在面结构光投影三维测量系统中,物体的背景和阴影是不可避免的,必须进行识别和去除。不合理的调制阈值将导致无效测量区域的误匹配以及局部点云空洞等问题,影响单视角重建的精度和效率。与现有的调制度分割方法不同,利用调制度直方图代替灰度直方图进行分析。同时,将Otsu算法和Sauvola算法引入调制度阈值计算中,并提出了一种结合频率矩阵的最大熵自动分割算法。针对反光背景下,单一调制度阈值无法进行分割的情况,提出了一种基于改进的Canny算法实现有效区域自动分割。实验结果表明:改进的自动分割算法在准确率、可靠性方面均优于传统方法,有效地避免调制度阈值选择的不合理导致点云边缘缺失和局部空洞等问题,实现了有效测量区域的自动分割。In fringe projection profilometry,background and shadow are inevitable in the image of an object,and must be identified and removed.Unreasonable modulation threshold will lead to mismatching of invalid measurement areas and local point cloud holes,which will affect the precision and efficiency of single view reconstruction.Otsu algorithm and Sauvola algorithm are introduced into the calculation of modulation threshold.Different from the existing modulation segmentation methods,the modulation-level histogram,instead of the Gray-level histogram,of the image is employed to determine the threshold and a maximum entropy automatic segmentation algorithm combined with frequency matrix is proposed.Moreover,an improved Canny algorithm is proposed to complete the automatic segmentation of the effective measuring area in reflective background.The experimental results show that the improved automatic segmentation algorithm is better than the traditional methods in accuracy and reliability,effectively avoids the problems of point cloud edge loss and local cavity caused by the unreasonable selection of modulation threshold,and realizes the automatic segmentation of effective measurement area.

关 键 词：多频外差 三维测量 结构光 调制度分割 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]