基于标志点匹配的散斑图像变形初值估计法  

Initial Displacement Estimation Method for Speckle Image Based on Marker Matching

作　　者：张红颖[1] 于之靖[1] 

机构地区：[1]中国民航大学电子信息与自动化学院,天津300300

出　　处：《光学学报》2017年第3期131-137,共7页Acta Optica Sinica

基　　金：国家自然科学基金民航联合基金(U1333105);中央高校基本科研业务费(3122015C016)

摘　　要：在数字散斑相关测量方法中,可靠的变形初值估计是获得亚像素精度的关键。利用标志点匹配技术,提出了一种新的变形参数初值估计法。该方法在散斑上粘贴反射系数极高的圆形标志点,为消除散斑背景对标志点提取的影响,提出一种改进的尺度不变特征转换算法,将极值点检测约束在显著的边缘区域,从而大大减少冗余特征点的提取,最后通过单应性变换得到全场变形,进而使得感兴趣区域中各像素点快速完成初值估计。制作散斑板子进行实验验证,结果表明,该方法得到的变形初值,只需要3~4次迭代就能够使亚像素迭代收敛,并获得准确、可靠的测量结果。For digital speckle correlation methods,the reliable initial displacement estimation is particularly important to achieve sub-pixel accuracy.Utilizing marker matching technology,a new initial value estimation method is proposed.This method sticks circular markers with high reflection coefficient on the speckles.In order to eliminate the effects of speckles on extracting points,an improved scale invariant feature transform algorithm detecting extreme points within significant edge region is presented,so the redundant feature points are greatly reduced in this way.At last,the homography transformation is executed to complete full field deformation,and the initial value of each pixel in the region of interest is estimated rapidly.Experiments are performed through making speckle plate and the results show that the initial values obtained by the proposed method can reach a fast convergence within 3-4iterations and consequently get accurate and reliable measurement results.

关 键 词：相干光学 光学测量 亚像素精度 初值估计 标志点匹配 尺度不变特征转换算法 

分 类 号：TN247[电子电信—物理电子学]