1. 写入文件

1.1 代码

#include <opencv2/opencv.hpp>
#include <time.h>
#include <iostream>
 
int main(int argc, char** argv)
{
  //write a yaml file
  cv::FileStorage fs_write("./test.yaml", cv::FileStorage::WRITE);
 
  time_t rawtime;
  time(&rawtime);
  fs_write << "Time" << asctime(localtime(&rawtime));
  
  std::vector<int> image_size = {1280, 800};
  fs_write << "imageSize" << image_size; 
 
  cv::Mat camera_matrix = (cv::Mat_<double>(3, 3) << 190, 0, 640, 
                                                     0, 190, 400, 
                                                     0, 0, 1);
  cv::Mat distort_coefficient = (cv::Mat_<double>(5, 1) << 0.1, 0.01, -0.001, 0, 0);
  fs_write << "cameraMatrix" << camera_matrix << "distCoeffs" << distort_coefficient;
    
  fs_write.release();
 
  return 0;
}

1.2 说明

• 使用cv::FileStorage创建文件对象，打开文件
• 使用<<符号向文件中写入信息
• release()关闭文件

1.3 输出文件结果

%YAML:1.0
---
Time: "Thu Nov 28 14:02:31 2019\n"
imageSize: [ 1280, 800 ]
cameraMatrix: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 190., 0., 640., 0., 190., 400., 0., 0., 1. ]
distCoeffs: !!opencv-matrix
   rows: 5
   cols: 1
   dt: d
   data: [ 1.0000000000000001e-01, 1.0000000000000000e-02,
       -1.0000000000000000e-03, 0., 0. ]

2. 读取文件

2.1 代码

#include <opencv2/opencv.hpp>
#include <iostream>
#include <vector>
 
int main(int argc, char **argv)
{
    //read a yaml file
    cv::FileStorage fs_read("./test.yaml", cv::FileStorage::READ);
 
    std::string time;
    //second method:use FileNode::operator >>
    fs_read["Time"] >> time;
 
    std::vector<int> image_size;
    fs_read["imageSize"] >> image_size;
 
    cv::Mat camera_matrix, distort_coefficient;
    fs_read["cameraMatrix"] >> camera_matrix;
    fs_read["distCoeffs"] >> distort_coefficient;
 
    std::cout << "Time: " << time << std::endl
              << "cameraMatrix: " << camera_matrix << std::endl
              << "distCoeffs: " << distort_coefficient << std::endl;
 
    fs_read.release();
 
    return 0;
}

REF：https://blog.csdn.net/feiyang_luo/article/details/103291475