3D shape measurement in fast high dynamic range based on projection intensity

Fringe projection profilometry is widely used in many fields due to its advantages of high speed, high accuracy, and robustness to ambient lighting and surface textures. However, it is susceptible to high dynamic range (HDR) objects. Therefore, a method to quickly calculate the optimal projected brightness was proposed. By solving the response relationship between camera and projector, and combined with a proposed simple method of projection brightness determination, the required projection brightness could be obtained. Then, based on the proposed image fusion algorithm, the obtained original images under each brightness were fused to obtain high-quality fused images and achieve high-precision three-dimensional reconstruction of HDR objects. Compared with the traditional methods, there was no need to blindly project and take a large number of pictures or calculate complex homography matrices. It only needed to project a uniform white light to the measured object, and the response function between the camera and the projector could be quickly solved, so as to obtain the required projection brightness, which greatly improved the measurement speed.