基于可控旋转的像机高精度标定技术

High-Accurate Camera Calibration Technique Based on Controllable Rotation

提出了一种基于可控旋转的主动视觉标定方法,通过控制像机围绕光心(或光心附近)做旋转运动,能够将等效焦距与其他参数分离开来,求解精确的等效焦距。该方法需要控制像机绕其坐标轴进行两次旋转以标定横纵等效焦距。当采用横纵等效焦距相等并且图像主点取为图像中心的简化成像模型时,只需要一次旋转运动即可标定像机线性参数。在此基础上提出了传统标定方法和基于可控旋转方法相结合的像机标定技术,控制摄像机拍摄空间坐标已知的标定块并做一定的旋转运动,从而高精度标定包含像差系数的像机内外参数。实验表明,使用基于可控旋转运动标定方法得到的像机参数进行位姿测量时达到了很高的精度。

A camera calibration technique based on controllable rotation for active vision system is proposed.The camera is controlled to rotate a known angle around（or around nearby） the optical center to calculate the accurate equivalent focus length departed from other parameters.This method needs two rotations to get the equivalent focus lengths along two axes.Using the simplified imaging model,that two equivalent focus lengths are set to equal and the principal point is on image center,only one rotation is required to get the linear camera parameters.And then a camera calibration method combined by controllable rotation and traditional two steps calibration is put forward to get all parameters including the distortion coefficients.Experiments show that the use of camera parameters obtained by calibration method based on the controlled rotation has a high accuracy for pose measurement.