High Reflection based on Phase Measurement Deflection (PMD) Research on Mirror 3D Reconstruction Method

王乐

宋展;孙红雨

硕士

山东科技大学

三维成像;;相位测量偏折术;;相位展开;;局部模糊;;积分重建

本文利用相位测量偏折术(Phase measuring deflectometry,PMD)检测速度快,灵敏度高,非接触以及成本低等优点实现对高反射镜面物体的三维重建,为了解决测量系统捕获形变条纹模糊的问题,提出了一种空间变化离焦去模糊的分析方法。首先对硬件系统进行标定,确定了相机的内部参数以及相机与参考平面、LCD显示屏的对应关系;接着利用多频外差时间解相位算法对相位展开,并对形变条纹进行预处理,建立空间变化的离焦模糊模型;最后通过三维块匹配算法(Block Matching 3D,BM3D)实现了模糊条纹聚焦的目的,并通过对圆形以及矩形标准平面镜进行实验,实验结果证明本文的方法能有效改善形变条纹的模糊量,提高解相位以及镜面重建的精度。本文的研究内容及结构框架主要有以下几个方面:1.相位测量偏折术的原理首先由计算机生成标准正弦条纹同时由LCD显示生成的条纹同步投射到研究对象上产生形变,对检测系统的相机、LCD现水平以及参考平面采用张正友标定法进行标定,同时选取测量系统的参数进行后续实验。2.相位测量包裹以及解包裹相位的技术作为本文的研究重点,首先通过理论分析选取标准四步相移求解包裹相位,对比传统时间相位和空间解相位算法的代表方法:傅里叶变化法和多频外差法对单幅条纹图和多幅条纹图进行解相位研究。针对形变条纹的预处理模块,首先分析了测量系统工业相机的有限景深导致局部模糊分析的情况,进而建立对应形变条纹空间变化的局部模糊图,结合反卷积算法得到高精度的解相位结果;3.结合测量系统的横向、纵向分辨率以及相位和梯度的关系,通过分析傅里叶变换全局积分法和基于Southwell模型区域波前重构算法的特点分别建立梯度和高度的数学模型,通过标准矩形平面镜和圆面镜三维重建,相继恢复三维面型,并分析了重建的误差:矩形平面镜的误差约为,圆形平面镜的误差约为,凹面镜的误差约为,最终的实验验证了本文提出的方法在高反射镜面物体三维重建过程中的有效性和精确性。

In this paper,the advantages of phase measuring deflectometry(PMD)detection speed,high sensitivity,non-contact and low cost are used to realize the three-dimensional reconstruction of highly reflective mirror objects.In order to solve the problem of blurring of deformation fringes captured by the measurement system,it is proposed An analysis method for defocusing and defocusing of spatial variation is presented.First,the hardware system is calibrated,and the internal parameters of the camera and the correspondence between the camera and the reference plane and the LCD display are determined.Then,the phase is expanded using a multi-frequency heterodyne time solution phase.algorithm,and the deformation fringes are preprocessed to establish a space.Variable defocus blur model;finally,the purpose of blur stripe focusing is achieved through three-dimensional block matching algorithm(Block Matching 3D,BM3D),and experiments on circular and rectangular standard plane mirrors are carried out.The experimental results prove that the method in this paper can effectively improve deformation The amount of fringe fringes improves the accuracy of dephasing and mirror reconstruction.The research content and structural framework of this article mainly include the following aspects:1.The principle of phase measurement deflection is that the standard sinusoidal fringe is first generated by the computer and the fringe generated by the LCD display is simultaneously projected onto the research object to produce deformation.The detection system is calibrated using the Zhang Zhengyou calibration method,including camera calibration and LCD display calibration.As well as the calibration of the reference plane,the parameters of the measurement system are selected for subsequent experiments.2.The techniques of phase measurement wrapping and unwrapping phase are the research focus of this paper.First,the standard four-step phase shift is used to solve the wrapped phase through theoretical analysis,and the representative methods of the traditional time phase and spatial phase unwrapping algorithms are compared:Fourier change method and Multi-frequency heterodyne method is used to study the phase of single and multiple fringe patterns.For the preprocessing module of deformed fringes,the situation of local blur analysis caused by the limited depth of field of the industrial camera of the measuring system is first analyzed,and then the local fuzzy map corresponding to the spatial change of the deformed fringes is established,and the deconvolution algorithm is combined to obtain high-precision dephasing results;3.Combining the horizontal and vertical resolutions of the measurement system and the relationship between phase and gradient,through the analysis of the characteristics of the Fourier transform global integration method and the wavefront reconstruction algorithm based on the Southwell model area,the mathematical models of gradient and height are established respectively.The three-dimensional reconstruction of the rectangular plane mirror and the round mirror successively restores the three-dimensional shape,and analyzes the reconstruction errors:the error of the rectangular plane mirror is about,the error of the round plane mirror is about,and the error of the concave mirror is about.The final experiment verified this article The effectiveness and accuracy of the proposed method in the three-dimensional reconstruction of highly reflective mirror objects.