Han Min, Xing Yibo, Wang Xiaohao, Li Xinghui
Opt Lett. 2024 Aug 1;49(15):4473-4476. doi: 10.1364/OL.531846.
Fringe projection profilometry based on MEMS micro-vibration mirrors is very promising due to its rapid projection, large depth of field, compact size, and low cost. Although high-frequency fringes can achieve accurate reconstruction, the projector must offer sufficient pixel resolution. In this paper, we proposed a high-resolution projection technique called the delay superposition method. During a single exposure time of the camera, the projector projects a group of low-resolution fringe patterns, which are delayed according to the movement characteristics of the vibration mirror. Then, the camera exposure superimposes these low-resolution images to form a high-resolution image. These two steps effectively subdivide the angle intervals, thereby achieving a pixel interpolation. Finally, experimental results show that the proposed method can significantly improve the projector's pixel resolution and reconstruction accuracy. The proposed method allows the MEMS projector's pixel resolution (along one direction) to far exceed that of common DLP projectors. It holds great application potential for high-frequency fringe projection.
基于MEMS微振动镜的条纹投影轮廓术因其投影速度快、景深大、尺寸紧凑和成本低而极具前景。尽管高频条纹可以实现精确重建，但投影仪必须具备足够的像素分辨率。在本文中，我们提出了一种称为延迟叠加法的高分辨率投影技术。在相机的单次曝光时间内，投影仪投射一组低分辨率条纹图案，这些图案根据振动镜的运动特性进行延迟。然后，相机曝光将这些低分辨率图像叠加以形成高分辨率图像。这两个步骤有效地细分了角度间隔，从而实现了像素插值。最后，实验结果表明，所提出的方法可以显著提高投影仪的像素分辨率和重建精度。所提出的方法使MEMS投影仪的像素分辨率（沿一个方向）远远超过普通DLP投影仪。它在高频条纹投影方面具有巨大的应用潜力。
