Abstract: In order to improve the flexibility and rapidity of 3D laser projection system,a calibration method of 3D laser projection system based on object spatial sampling is proposed.A point on the object to be projected is directly mapped to the pixel plane of the monocular camera through perspective transformation,and then the homography matrix between the camera pixel plane and the digital quantity plane of the galvanometer is used to obtain the corresponding digital quantity control signal of the point.The whole 3D laser projection system can be calibrated by taking two images.The experimental results show that the calibration time of the projection system calibrated by this method is less than 5 min,and the projection positioning error is less than ±0.4 mm in the range of 3 m,which meets the application requirements of industrial scenarios.Meanwhile,the method is meaningful for the cooperative work of multiple galvanometers in large objects to be projected.

Key words: Machine vision, Perspective transformation, Planar homography transformation, Image processing, Pose estimation