基于灰度插值的条纹图像位移亚像素检测算法  

Algorithm for Sub-Pixel Detection of Fringe Image Displacement Based on Gray-Level Interpolation

作　　者：李舒航 高旭[1] 刘兆武[2] 胡文浩 Li Shuhang;Gao Xu;Liu Zhaowu;Hu Wenhao(School of Opto-Electronic Engineering,Changchun University of Science and Technology,Changchun,Jilin 130022,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun,Jilin 130033,China)

机构地区：[1]长春理工大学光电工程学院,吉林长春130022 [2]中国科学院长春光学精密机械与物理研究所,吉林长春130033

出　　处：《光学学报》2021年第10期125-133,共9页Acta Optica Sinica

基　　金：国家自然科学基金(51505078);中国博士后科学基金(2018M641778);吉林省科技厅优秀青年人才基金(20180520187JH);吉林省教育厅“十三五”科学技术基金(JJKH20190544KJ)。

摘　　要：基于光栅干涉条纹的位移测量系统,提出了一种基于灰度插值的条纹图像位移检测算法即灰度极值法。首先,对光学位移测量系统进行了介绍;其次,阐述了灰度极值算法的原理。为了验证算法,对光学系统条纹图像进行了软件仿真,并对其进行了亚像素级定位算法仿真,对比分析了传统图像相关法与光流法,得到了相对误差曲线,所提算法的精度为1.797 pixel。最后,搭建了光栅干涉式位移测量光学系统,采集移动条纹数据并利用灰度极值算法进行了解调,实现了亚像素级位移解调,大量程下实验精度达到1.093 pixel。实验结果表明:灰度极值算法在大量程下的测量精度最高,可对位移量进行亚像素级定位,且算法具有计算时间短、受噪声影响小、鲁棒性强的特点。所提方法也可适用于自相干莫尔条纹系统、光电轴角编码器等其他位移测量系统的图像式位移信号解调。Based on the displacement measurement system of grating interference fringes,this paper proposed a fringe image displacement detection algorithm based on gray interpolation,i.e.grayscale extreme value algorithm.First,the optical displacement measurement system is introduced.Then,the principle of grayscale extreme value algorithm is explained.In order to verify this algorithm,the fringe image of the optical system was simulated and the algorithm simulation was used to locate the image at sub-pixel level.The traditional image correlation method and the optical flow method were compared and analyzed,and the relative error curve was obtained.The proposed algorithm accuracy is 1.797 pixel.Finally,a grating interferometric optical system was built,and the moving stripe data were collected and demodulated using the grayscale extreme value algorithm to realize sub-pixel level displacement demodulation with an experimental accuracy of 1.093 pixel under a large range.The experimental results show that the grayscale extreme value algorithm possesses a high measurement accuracy in a large range and can be used to realize sub-pixel level positioning.Moreover,it possesses the characteristics of short calculation time,little influence of noise,and strong robustness.The proposed method is also suitable for image-based displacement signal demodulation of other systems,such as self-coherent moire fringe system and photoelectric shaft encoder.

关 键 词：测量 灰度插值 条纹图像 位移 精密测量 

分 类 号：TP23[自动化与计算机技术—检测技术与自动化装置]