openCV学习笔记（十九） —— XML和YAML文件的写入和读取

拼搏现实的明天。 2021-09-27 07:26 357阅读 0赞

以下程序来源于《opencv3入门经典》

# XML和YAML文件的写入 #

#include<opencv2/opencv.hpp>
    #include <vector>
    #include <time.h>
    
    using namespace std;
    using namespace cv;
    
    int main()
    {
    	//初始化
    	FileStorage fs("test.yaml", FileStorage::WRITE);
    
    	//开始文件写入
    	fs << "frameCount" << 5;
    
    	time_t rawtime;
    	time(&rawtime);
    	fs << "calibrationDate" << asctime(localtime(&rawtime));
    
    	Mat cameraMatrix = (Mat_<double>(3, 3) << 1000, 0, 320, 0, 1000, 240, 0, 0, 1);
    	Mat distCoeffs = (Mat_<double>(5, 1) << 0.1, 0.01, -0.001, 0, 0);
    
    	fs << "cameraMatrix" << cameraMatrix << "distCoeffs" << distCoeffs;
    	fs << "features" << "[";
    	for (int i = 0; i < 3; ++i)
    	{
    		int x = rand() % 640;
    		int y = rand() % 480;
    		uchar lbp = rand() % 256;
    
    		fs << "{:" << "x" << x << "y" << y << "lbp" << "[:";
    		for (int j = 0; j < 8; ++j)
    		{
    			fs << ((lbp >> j) & 1);
    		}
    		fs << "]" << "}";
    	}
    
    	fs << "]";
    	
    	fs.release();
    
    	printf("文件读写完毕，请在工程目录下查看生成的文件~\n");
    
    	waitKey(0);
    
    	return 0;
    }

# 运行结果  #

![70][]

如果我们修改上面代码的 FileStorage fs(“text.yaml”, FileStorage::WRITE)这一句代码，将其中的“test.yaml”的后缀换为xml、yml、TXT、甚至doc，都是可以得到运行结果的，大家不妨试一下。

# XML和YAML文件的读取  #

#include<opencv2/opencv.hpp>
    #include <vector>
    #include <time.h>
    
    using namespace std;
    using namespace cv;
    
    int main()
    {
    	//改变console字体颜色
    	system("color 6F");
    
    	//初始化
    	FileStorage fs2("test.yaml", FileStorage::READ);
    
    	//第一种方法，对FileNode操作
    	int frameCount = (int)fs2["frameCount"];
    
    	std::string date;
    	//第二种方法，使用FileNode运算符>>
    	fs2["calibrationDate"] >> date;
    
    	Mat cameraMatrix, distCoeffs2;
    	fs2["cameraMatrix"] >> cameraMatrix;
    	fs2["distCoeffs"] >> distCoeffs2;
    
    	cout << "frameCount: " << frameCount << endl
    	<< "calibration date: " << date << endl
    	<< "camera matrix:\n" << cameraMatrix << endl
    	<< "distortion coeffs:\n" << distCoeffs2 << endl;
    
    	FileNode features = fs2["features"];
    	FileNodeIterator it = features.begin(), it_end = features.end();
    
    	int idx = 0;
    	std::vector<uchar> lbpval;
    
    	//使用FileNodeIterator遍历序列
    	for (; it != it_end; ++it, ++idx)
    	{
    		cout << "feature #" << idx << ":";
    		cout << "x=" << (int)(*it)["x"] << ", y = " << (int)(*it)["*y"] << ", lbp: (";
    		//我们也可以使用FileNode >> std::vector操作符来很容易地读数值阵列
    		(*it)["lbp"] >> lbpval;
    		for (int i = 0; i < (int)lbpval.size(); ++i)
    		{
    			cout << " " << (int)lbpval[i];
    		}
    		cout << ")" << endl;
    	}
    
    	fs2.release();
    
    	//程序结束，输出一些帮助文件
    	printf("\n文件读取完毕，请输入任意键结束程序~\n");
    	getchar();
    	
    	return 0;
    }

# 运行结果  #

![70 1][]

# 常见问题： #

出现 error C4996: 'asctime': This function or variable may be unsafe. Consider using asctime\_s instead这个问题

**解决措施：**

右击工程-->属性-->配置属性 --> C/C++ --> 命令行-->输入"/D \_CRT\_SECURE\_NO\_WARNINGS"-->"确定"，这样问题就可以解决了

[70]: /images/20210923/a56c464404f84062b7847a6d68450c54.png
[70 1]: /images/20210923/0aa1ce1149ee43ae97baf29e5028edf2.png