基于单帧四灰阶条纹投影的实时相位测量轮廓术  

Real-Time Phase Measuring Profilometry Based on Single-Shot Four-Grayscale Fringe Projection

作　　者：杨超智 曹益平[1] Yang Chaozhi;Cao Yiping(College of Electronics and Information Engineering,Sichuan University,Chengdu,Sichuan 610065,China)

机构地区：[1]四川大学电子信息学院,四川成都610065

出　　处：《光学学报》2021年第18期128-136,共9页Acta Optica Sinica

基　　金：国家科技重大专项(2009ZX02204-008)。

摘　　要：提出了一种基于单帧四灰阶条纹投影实时测量物体三维面形的新方法。该方法将四灰阶中非零三阶的不同灰度依次等宽循环排列以编码成一帧三灰阶条纹,将该三灰阶条纹投影到待测物体上,利用图像采集相机采集相应的四灰阶变形条纹,其中第四灰阶对应变形条纹图中的阴影区域。采用图像分割方法分别提取该四灰阶变形条纹中的三阶非零条纹,并通过二值化方法解调出三帧占空比为1/3且条纹相对错位1/3周期的二值化变形条纹。对上述二值化变形条纹进行基频提取后,通过傅里叶逆变换处理,可获得三帧相移量为2π/3的正弦条纹,最后利用相位测量轮廓术对物体三维面形进行恢复。实验验证了所提方法的可行性,所提方法刷新率快,且对投影仪伽马效应不敏感,在实时三维测量中具有广阔的应用前景。A new real-time three-dimensional(3 D)measuring method is proposed based on single-shot four-grayscale fringe projection,in which different non-zero three-scale grays in the four gray levels are cyclically arranged in equal width to encode a frame of three-grayscale fringe pattern.When the three-grayscale fringe pattern is projected onto the measured object,the corresponding four-grayscale deformed pattern is captured by the imaging camera,and the fourth grayscale corresponds to the shadow area in the deformed pattern.By the image segmentation method,non-zero three-grayscale fringes in the four-grayscale deformed pattern can be extracted respectively.After binarization,three frames of binary deformed patterns with 1/3 duty cycle and relative displacement of 1/3 period can be demodulated.So three frames of sinusoidal fringes with a 2π/3 shifted phase can be extracted by the inverse Fourier transform after filtering the corresponding fundamental frequency of the three frames of binary deformed patterns,and the 3 D shape of the object can be reconstructed by phase measuring profilometry(PMP).The experimental results confirm the feasibility of the proposed method.Because of the fast refreshing rate and the insensitivity to the gamma effect of the projector,the proposed method has a potential application prospect in real-time 3 D measurement.

关 键 词：测量 三维测量 相位测量 四灰阶条纹 二元光栅 单帧条纹 实时测量 

分 类 号：O436[机械工程—光学工程]