Real-time line-structured light measurement system based on Scheimpflug principle

A measurement system based on the Scheimpflug principle is designed in this paper to solve the problem of difficulty in clear imaging due to excessively small depth of field in line-structured light close-range photogrammetry. A conversion model from the image coordinate system to the measured object coordinate system is established through the spatial projection relationship. The calibration method of the measurement system under Scheimpflug conditions is investigated and the calibration of the measurement system is completed through nonlinear iterative optimization, and the calibration re-projection error is less than 0.3 pixels. GPU (graphic processing unit) acceleration processing is performed on the center extraction of line-structured light stripe to achieve real-time output at a high frame rate. The processing time for a single 1024 × 1280 image is only 2.14 ms after acceleration. Experimental results showed that the measurement system can realize the three-dimensional measurement of complex shapes and high-reflectivity surfaces with high detection accuracy and output frame rate.