openCV学习笔记（十九） —— XML和YAML文件的写入和读取

以下程序来源于《opencv3入门经典》

XML和YAML文件的写入

#include
#include 
#include 

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_(3, 3) << 1000, 0, 320, 0, 1000, 240, 0, 0, 1);
	Mat distCoeffs = (Mat_(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 

 

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
#include 
#include 

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 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 

 

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