基于透视畸变矫正的高精度相机标定方法

Accurate Camera Calibration Method Based on Perspective Distortion Correction

传统基于圆阵列标靶的相机标定方法通常把椭圆中心作为控制点坐标,忽略了透视投影造成的畸变,给相机标定引入了系统性误差。针对此,提出了一种基于透视畸变矫正的高精度相机标定方法。首先,利用椭圆中心进行相机粗标定;其次,用粗标定参数求相机纯旋转对应的射影变换,直接对椭圆参数进行变换,求取真实的圆心投影;最后,用真实的圆心投影进行相机精标定。仿真和实验结果证明,所提方法有效降低了相机标定的重投影误差与参数标准差,能满足工业视觉测量对相机标定的简便、高精度的要求。

Traditional camera calibration methods with a circular array target typically use the center of the ellipse as the control point coordinate,ignoring distortion from projective effects and introducing systematic errors into the calibration process.Therefore,we propose an accurate camera calibration method based on perspective distortion correction.Herein,first,the camera was coarse calibrated using the center of the ellipse.Second,using the coarse calibration parameters,the projective transformation corresponding to the camera’s pure rotation was determined,and the ellipse parameters were directly changed to yield the true projected center of the circle.Finally,we used the obtained center to perform fine camera calibration.According to the simulation and experimental results,the suggested technique significantly reduces the reprojection error and parameter standard deviation of camera calibration;it can meet the simple,high-precision criteria of camera calibration for industrial vision measurement.