Real-time 3D measurement system based on infrared light projection

Optical three-dimensional(3D) shape measurement technology has been widely used in industrial manufacturing, defect detection, reverse engineering, human modeling, pattern recognition and other fields. As industrial standards continue to advance, we are demanding more and more functionality and performance from our imaging systems. At present, although a real-time imaging system based on visible light from fringe projection can image well and achieve real-time imaging speed, it is still not applicable to face scanning, shaded object imaging, etc. However, most of the 3D imaging based on the infrared projector cannot achieve the effect of real-time imaging due to the slow scanning speed. In this paper, we combine the near-infrared structured light illumination system with the stereo phase unwrapping method with multi-camera calibration to realize high-precision real-time 3D imaging. The MEMS near-infrared fringe projection device is used as a structured light illumination source, which can reduce the damage of visible structured light to human eyes and animals. Experiments are carried out on static and dynamic scenes, and it is verified that the designed system can achieve high-speed and high precision 3D reconstruction at the speed of 100 frames per second, and the measurement accuracy is about 100µm.