【作者】 翁嘉文；

【导师】 钟金钢；

【作者基本信息】 暨南大学 ， 光学， 2004， 硕士

【摘要】 三维轮廓术在高速在线检测、质量监控、机器视觉以及医疗诊断等领域的应用日益广泛。具有非接触性的光学投影式测量方法由于其高分辨率、无破损、数据获取速度快等优点而被公认为最有前途的三维轮廓测量方法。本文以傅里叶变换轮廓术所存在的缺陷为出发点，提出了一种新的测量方法——小波变换轮廓术，并从理论，以及计算机模拟和实验各方面进行了深入的研究。 首先在傅里叶变换的基础上引入高斯窗函数提出了窗口傅里叶变换条纹分析法，进而在高斯窗函数中引入伸缩变换提出伸缩窗口傅里叶变换分析。并从理论和实验中分析了这两种方法的局限性。 再而提出了小波变换轮廓术，并通过理论分析和实际测量证明了该技术的有效性。另外，还对小波变换的关键技术问题，如母小波函数的选择、小波尺度函数的构造以及小波变换脊的确定进行了详细的研究与分析。 最后，为了解决非连续物体的包裹相位解调的问题，本论文发展了钟金钢老师提出的双频条纹相位查表法，结合小波变换轮廓术，提出了双频光栅+小波变换+查表相位解包技术，实现在一幅变形双频光栅图像中进行小波分析得到两个频率所对应的确定的相位分布。该方法可以用于由具有台阶、陡峭表面和噪声等复杂表面形成的非平稳光栅信号的分析。更多还原

【Abstract】 The application of 3-D shape measurement is more and more important in the domain of industrial inspection, quality controlling, machine vision, and medical science, etc. And because of its high precision, nondestructive feature san also fastness of data acquisition, the method of non-contact optical measurement becomes very popular. Take the limitation of Fourier transform profilometry as the beginning, wavelet transform profilometry is brought forward as a new measurement method. The theoretical analysis, simulation and experimental results are presented.Firstly, the Gauss window is introduced to Fourier transform, i.e. Gabor transform, and applied to the fringe analysis. By introducing dilating transformation to the Gauss window function on the space scale, dilating Gabor transform is got. The theoretical analysis, simulation and experimental results are presented that demonstrate the limitation of them.Furthermore, wavelet transform(WT) is applied to analyze the spatial carrier-fringes, that is, wavelet transform profilometry. The theoretical analysis, simulation and experimental results presented demonstrate the validity of the principle. And the key technique of WT, such as the selection of the mother wavelet, the scale function, and the ridge of the wavelet transform are studied.Finally, the spatial bi-frequency grating pattern, the ratio of the two frequencies of that is an irrational number, is introduced. By using the wavelet transform profilometry, the wrapped modulated phase distributions corresponding to the two frequencies respectively are got in one bi-frequency grating pattern. And then applying the phase unwrapping by a lookup table method for unwrapping, the determinate phases corresponding to the two frequencies are got. Such technique can be applied to the analysis of the nonstationary and transient signals.更多还原