Faculty of Applied Engineering, University of Antwerp, 2020 Antwerp, Belgium.
Department of Mechanical Engineering, Pleinlaan 2, Vrije Universiteit Brussel, 1050 Brussel, Belgium.
Sensors (Basel). 2021 Apr 7;21(8):2574. doi: 10.3390/s21082574.
Shape from focus is an accurate, but relatively time-consuming, 3D profilometry technique (compared to e.g., laser triangulation or fringe projection). This is the case because a large amount of data that needs to be captured and processed to obtain 3D measurements. In this paper, we propose a two-step shape-from-focus measurement approach that can improve the speed with 40%. By using a faster profilometry technique to create a coarse measurement of an unknown target, this coarse measurement can be used to limit the data capture to only the required frames. This method can significantly improve the measurement and processing speed. The method was tested on a 40 mm by 40 mm custom target and resulted in an overall 46% reduction of measurement time. The accuracy of the proposed method was compared against the conventional shape from focus method by comparing both methods with a more accurate reference.
聚焦法是一种精确但相对耗时的三维轮廓测量技术（与激光三角测量或条纹投影相比）。这是因为需要捕获和处理大量数据才能获得 3D 测量结果。在本文中，我们提出了一种两步聚焦法测量方法，可以将速度提高 40%。通过使用更快的轮廓测量技术来创建未知目标的粗略测量，可以使用该粗略测量来限制仅捕获所需的帧数。这种方法可以显著提高测量和处理速度。该方法在一个 40mm×40mm 的定制目标上进行了测试，测量时间总体减少了 46%。通过与更准确的参考方法比较，对所提出的方法的准确性与传统的聚焦法进行了比较。
