为了实现结构光三维成像系统参数的简易、快速标定,提出一种利用单应矩阵获取大量标定数据的方法,步骤如下:获取立体标靶上左右两侧矩形框角点的图像坐标和对应的世界坐标,分别计算左右两侧靶面从图像坐标变换到世界坐标的单应矩阵;将图像中立体标靶矩形框内所有的像素点应用到计算出的单应矩阵中,得到与之对应的世界坐标;利用图像中立体标靶的靶面上几乎所有像素点的图像坐标和对应世界坐标来执行三维成像系统的标定。设计了一种与该标定方法相对应的立体标靶,基于该立体标靶对结构光三维成像系统进行标定,并利用标定后的系统进行实验。实验结果表明,该标定方法具有较高的标定精度,重建的三维点云图具有很好的视觉效果。该标定方法过程简单,可降低标定成本,具有实际应用价值。

To achieve a simple and fast calibration of parameters for three-dimensional imaging system with structured light, a method of obtaining a large number of calibration data using a homography matrix is presented. First, the image coordinates and the corresponding world coordinates of the rectangular corner points on the left and right sides of a stereo target are obtained, and the homography matrices of the left and right sides of the target surface from the image coordinates to the world coordinates are then calculated respectively. Next, all the pixels in the rectangular frame of the stereo target in the image are applied to the calculated homography matrix to obtain the corresponding world coordinates. Finally, we calibrate the three-dimensional imaging system using the image coordinates of nearly all the pixels on the target surface of the stereo target in the image and the corresponding world coordinates. A stereo target corresponding to the proposed calibration method is designed. Based on the stereo target, the three-dimensional imaging system with structured light is calibrated and experiments are carried out using the calibrated system. The experimental results show that the calibration method has high calibration accuracy, the reconstructed three-dimensional point cloud image has a good visual effect, and the calibration process is simple, which reduces the cost of calibration and is valuable for practical applications.