基于正三角形平面模板的摄像机标定与重建

Camera calibration and reconstruction using a planar pattern spliced by equilateral triangle

提出一种采用正三角形平面模板标定摄像机内参数并进行重建的方法。模板包含一个正三角形和其重心至3个顶点的连线。用摄像机拍摄3幅以上不同位姿的模板图像,并提取每幅图像上角点的亚像素级坐标,然后计算消失点并拟合消失线,再由两组正交直线的消失点求得圆环点的图像坐标,最后线性求解出摄像机内参数。给出了两种弱化条件的模板,并介绍了恢复欧氏尺寸和摄像机部分外参数的方法。该方法降低了对标定模板的要求,模拟实验和真实实验的结果证明了其具有较高的标定精度。

A practical approach of camera calibration and reconstruction based on an equilateral triangle planar pattern is presented. The pattern contains three sides of an equilateral triangle and three connection lines which connect its center of gravity to its three vertices respectively. More than three pattern images are captured from different poses,and sub-pixel coordinates of corners are extracted from each pattern image. Three vanishing points are calculated out which are used to fit the vanishing line.The image coordinates of circular points are deduced according the vanishing points of two groups of orthogonal lines. Finally,all the five intrinsic parameters of camera are determined linearly according the coordinates of circular points. Two further weakened condition patterns are given,as well as methods to recover Euclidean dimensions and part of the extrinsic parameters of the camera. Experiments with simulated data and real images show that the approach is robust and accurate.