通过一张图片基于张正友标定的2D视觉标定，其结果为一个单应性矩阵，基于Opencv的角点提取，标定的计算是自己编写，内有注释和原理，已在工程实践中得到应用。-Zhang Zhengyou based 2D calibration for camera calibration by a picture, the result is a homography, extraction based on corner Opencv, the calibration is calculated to wr