Omidi Parsa, Najiminaini Mohamadreza, Diop Mamadou, Carson Jeffrey J L
Imaging Program, Lawson Health Research Institute, St. Joseph's Health Care, London, ON, N6A 4V2, Canada.
School of Biomedical Engineering, Western University, London, ON, N6A 3K7, Canada.
Sci Rep. 2021 May 14;11(1):10367. doi: 10.1038/s41598-021-88136-4.
Spatial resolution in three-dimensional fringe projection profilometry is determined in large part by the number and spacing of fringes projected onto an object. Due to the intensity-based nature of fringe projection profilometry, fringe patterns must be generated in succession, which is time-consuming. As a result, the surface features of highly dynamic objects are difficult to measure. Here, we introduce multispectral fringe projection profilometry, a novel method that utilizes multispectral illumination to project a multispectral fringe pattern onto an object combined with a multispectral camera to detect the deformation of the fringe patterns due to the object. The multispectral camera enables the detection of 8 unique monochrome fringe patterns representing 4 distinct directions in a single snapshot. Furthermore, for each direction, the camera detects two π-phase shifted fringe patterns. Each pair of fringe patterns can be differenced to generate a differential fringe pattern that corrects for illumination offsets and mitigates the effects of glare from highly reflective surfaces. The new multispectral method solves many practical problems related to conventional fringe projection profilometry and doubles the effective spatial resolution. The method is suitable for high-quality fast 3D profilometry at video frame rates.
三维条纹投影轮廓术中的空间分辨率在很大程度上取决于投射到物体上的条纹数量和间距。由于条纹投影轮廓术基于强度的特性，条纹图案必须相继生成，这很耗时。因此，高动态物体的表面特征很难测量。在此，我们介绍多光谱条纹投影轮廓术，这是一种新颖的方法，它利用多光谱照明将多光谱条纹图案投射到物体上，并结合多光谱相机来检测由于物体导致的条纹图案变形。多光谱相机能够在单次快照中检测代表4个不同方向的8个独特单色条纹图案。此外，对于每个方向，相机检测两个π相移条纹图案。每对条纹图案可以相减以生成差分条纹图案，该图案可校正照明偏移并减轻高反射表面眩光的影响。这种新的多光谱方法解决了许多与传统条纹投影轮廓术相关的实际问题，并使有效空间分辨率提高了一倍。该方法适用于以视频帧率进行高质量快速三维轮廓测量。
