This paper reports a straightforward technique for three-dimensional (3D) visualization of a flow profile by a hybrid algorithm combining Fourier transform orthogonal fringe projection and laser speckle imaging techniques. The use of orthogonal projection aims to suppress the zero order allowing surface reconstruction with high spatial resolution and accuracy while analyzing the intensity fluctuations of diffuse backscattered laser light providing 2D flow information. Once both are achieved, 3D flow visualization can be displayed. The method is experimentally validated first with a plastic tube filled with scattering liquid (milk) running at various controlled flow rates and then with the tube embedded under scattering layers (chicken breast) of varying thickness. The system includes a single, common camera, a commercial projector (profilometry channel), a laser light source (flow channel), and a computer station. In addition, orthogonal projection processing was combined with Hilbert transform, increasing the visualization and resolution of the measured flow profile.

中文翻译：

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结合正交投影傅里叶变换轮廓测量和激光散斑成像的混合方法，用于流动轮廓的 3D 可视化

本文报告了一种通过结合傅立叶变换正交条纹投影和激光散斑成像技术的混合算法对流动剖面进行三维 (3D) 可视化的简单技术。正交投影的使用旨在抑制零级，从而在分析提供 2D 流动信息的漫背散射激光的强度波动的同时，以高空间分辨率和精度进行表面重建。一旦两者都实现，就可以显示 3D 流可视化。该方法首先通过一个装有散射液体（牛奶）的塑料管以各种受控流速运行，然后将管嵌入不同厚度的散射层（鸡胸肉）下进行实验验证。该系统包括一个单一的、通用的摄像头，一台商用投影仪（轮廓测量通道）、一个激光光源（流动通道）和一个计算机站。此外，正交投影处理与希尔伯特变换相结合，增加了测量流剖面的可视化和分辨率。