Zhu Zhenmin, You Duoduo, Zhou Fuqiang, Wang Sheng, Xie Yulin
Opt Express. 2021 Jan 18;29(2):2162-2171. doi: 10.1364/OE.416179.
Measurement of high dynamic range objects is an obstacle in structured light 3D measurement. They entail both over-exposed and low-exposed pixels in a single exposure. This paper proposed a polarization-enhanced fringe pattern (PEFP) method that a high dynamic range image can be obtained within a single exposure time. The degree of linear polarization (DOLP) is calculated using the polarization properties of reflected light and a linear polarizer in fixed azimuth in this method. The DOLP is efficiently estimated by the projected polarization-state-encode (PSE) pattern, and it does not need to change the state of the polarizer. The DOLP depends on light intensity rather than the reflectivity of the object surfaces indicated in experimental results. The contrast of fringe patterns was enhanced, and the quality of fringe patterns was improved by the proposed method. More sufficient 3D point clouds and high-quality shape can be recovered using this method.
高动态范围物体的测量是结构光三维测量中的一个障碍。在单次曝光中，它们会同时出现过曝光和低曝光像素。本文提出了一种偏振增强条纹图案（PEFP）方法，该方法可在单次曝光时间内获得高动态范围图像。在该方法中，利用反射光的偏振特性和固定方位的线性偏振器计算线性偏振度（DOLP）。通过投影偏振态编码（PSE）图案有效地估计DOLP，且无需改变偏振器的状态。实验结果表明，DOLP取决于光强而非物体表面的反射率。该方法增强了条纹图案的对比度，提高了条纹图案的质量。使用该方法可以恢复更充足的三维点云和高质量的形状。
