Parallel-based calibration method for line-structured light vision sensor

Determining the relative ubiety between the camera and the structured light plane projector is a classical problem in the measurement of line-structured light vision sensors. A geometrical calibration method based on the theory of vanishing points and vanishing lines is proposed. In this method, a planar target with several parallel lines is used. By moving the target to at least two different positions randomly, we can obtain the normal vector of the structured light plane under the camera coordinate system; as the distance of each two adjacent parallel lines has been known exactly, the parameter D of the structured light plane is determined; therefore, the function of the structured light plane can be confirmed. Experimental results show that the accuracy of the proposed calibration method can reach 0.09 mm within the view field of about 200 x 200 mm. Moreover, the target used in our calibration method can be easily produced precisely, and the calibration method is efficient and convenient as its simple calculation and easy operation, especially for onsite calibration. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)