Research On The Modeling And Calibration Technique Of3D Measurement System Based On Structured Light

According to careful analysis of the exiting3D measurement and reconstruction techniques, the mathematical model of3D measurement structured light system and linear/non-linear calibration model of camera is proposed in this paper, and the new calibration method of projector is proposed, too.This paper establishes the new mathematical model of3D measurement structured light system based on the models of the camera and the projector, which introduce how to obtain3D information of the object.This paper improves the exiting linear calibration method of the camera and the proposed method by Zhang. Z. Y, and proposes the improved non-linear calibration method of the camera (the improved Newton-Raphson algorithm). With this improved method and algorithm, this paper got the good accurate calibration result.This paper proposed the new calibration method of projector. The key of this method is to enable the projector to "capture" images like that of a camera. This method used the40%gray level reference checkerboard image which is illuminated by computer. First, the reference checkerboard is projected onto the calibration board plane of camera. Second, using camera, capture images of the reference checkerboard projected on the board plane. Using the camera calibration results, calculate the3D position of the X-points on the reference checkerboard. With the3D coordinates of these X-points, using camera calibration method, complete the calibration of the projector. Using this projector calibration method, this paper completes the calibration of the structured light3D measurement system. This calibration method is fast, accurate, and very easy to implement.In the last part, using the proposed calibration method and fast three-step phase-shifting algorithm, this paper provides3D reconstruction experimental results.