A simple calibration procedure for structured light system

The structured light system with a camera and a projector is widely used in various fields. However, the accurate calibration, which is crucial for a structured light system, is usually complicate and time-consuming, especially in the projector calibration stage. In addition, the calibration error of a projector is relatively bigger than a camera. Hence, a structured light system without the projector calibration can greatly reduce the system calibration error and simplify the calibration process. In this paper, a calibration method without projector calibration is proposed, in which the projector's line-of-sights serves as spatially vectors invariant to the environment. By introducing four reference planes and building look-up-tables for the camera-projector pixel correspondence, the 3D reconstruction of the system can be obtained without any projector's information. A series of experiments were performed to evaluate the proposed method, and it turned out that its accuracy is about 0.0925mm. •We proposed a simple calibration method for the structured light system.•The projector calibration is completely avoided.•There is no error-coupling in the proposed method.•The calibration procedure is easy to operate.•The error is found to be about 0. 0925mm.