opencv十二点标定

OpenCV的十二点标定法是在九点标定法的基础上增加了三个点，以提高标定精度。这三个点分别位于棋盘格的左上角、右上角和右下角。与九点标定法类似，十二点标定法也需要使用多组不同角度的图片进行标定。下面是使用C++实现OpenCV的十二点标定法的代码：

#include <opencv2/opencv.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main()
{
    // 定义棋盘格的行数和列数
    int board_w = 11;
    int board_h = 8;

    // 定义棋盘格中每个方格的大小
    float square_size = 20;

    // 定义棋盘格的三维坐标
    vector<Point3f> obj;
    for (int i = 0; i < board_h; i++)
    {
        for (int j = 0; j < board_w; j++)
        {
            obj.push_back(Point3f(j * square_size, i * square_size, 0));
        }
    }

    // 定义图像中棋盘格的二维坐标
    vector<vector<Point2f>> image_points;
    vector<Point2f> corners;

    // 读取多张图片进行标定
    for (int i = 1; i <= 20; i++)
    {
        // 读取图片
        Mat image = imread("image_" + to_string(i) + ".jpg");

        // 寻找棋盘格角点
        bool found = findChessboardCorners(image, Size(board_w, board_h), corners);

        // 如果找到了角点，则进行亚像素级角点检测
        if (found)
        {
            Mat gray;
            cvtColor(image, gray, COLOR_BGR2GRAY);
            cornerSubPix(gray, corners, Size(11, 11), Size(-1, -1), TermCriteria(TermCriteria::EPS + TermCriteria::COUNT, 30, 0.1));

            // 将角点添加到图像坐标中
            image_points.push_back(corners);

            // 在图像中绘制角点
            drawChessboardCorners(image, Size(board_w, board_h), corners, found);
            imshow("image", image);
            waitKey(0);
        }
    }

    // 进行标定
    Mat camera_matrix, dist_coeffs;
    vector<Mat> rvecs, tvecs;
    calibrateCamera(objectPoints, image_points, Size(image.cols, image.rows), camera_matrix, dist_coeffs, rvecs, tvecs);

    // 输出标定结果
    cout << "camera_matrix:" << endl << camera_matrix << endl;
    cout << "dist_coeffs:" << endl << dist_coeffs << endl;

    return 0;
}