In this paper, the effect of checker size and checkerboard angle on the accurate calibration for a structured light system is presented. Relations between calibration error and checker size, fitting plane error and checkerboard angle are also studied. | Journal of Science & Technology 127 (2018) 016-021 Improving the Accuracy of the Calibration Method for Structured Light System Nguyen Thi Kim Cuc* , Nguyen Van Vinh, Nguyen Thanh Hung, Nguyen Viet Kien Hanoi University of Science and Technology, No. 1, Dai Co Viet, Hai Ba Trung, Hanoi, Viet Nam Received: August 10, 2017; Accepted: May 25, 2018 Abstract In a structured light system, calibration is an important step for estimating the intrinsic and extrinsic parameters of the camera and projector. System calibration errors directly affect the measurement errors. Therefore, the accurate calibration is the main prerequisite for a successful and accurate surface reconstruction. In this paper, the effect of checker size and checkerboard angle on the accurate calibration for a structured light system is presented. Relations between calibration error and checker size, fitting plane error and checkerboard angle are also studied. The purpose of the research is to achieve high accuracy when calibrating the system, by selecting the optimum checker size and determining the limited checkerboard angle ∆ in the whole volume of measurement 200(H)×250(W)×100(D)mm3 Keywords: Structured light system, 3D Surface Measurement, Calibration. 1. Introduction relation between the checker corners found on a camera coordinate system and a world coordinate system attached to the checkerboard plane. In [9], the optimal checker size for accurate calibration system, however, it lacks of accuracy in checkerboad position and orientation checkerboard, and the correlation between calibration error and checker size have not been studied. Structured light measurement system (SLMS), has been widely used in the fields of artworks preservation, entertainment, security and medicine. Featuring high speed, ease of use, accuracy and flexibility than most of its competitors at a lower cost, this technique is only impeded by its cumbersome calibration process. [1] In our research, the calibration .