c++ - openCV 存储文件错误 :

Question

我正在尝试从 .yaml 文件加载矩阵，但 opencv 给我以下错误:

OpenCV Error: Parsing Error (myFile.yaml(1): valid xml should start with ') OpenCV Error: Parsing Error (myFile.yaml(1): Tag should start with '<'> in unknown function)

这是我的写入存储文件，工作正常:

cv::FileStorage fs("myFile.yaml", cv::FileStorage::APPEND);   
while(counter<_imgPtrVector.size()){    
    unsigned char* _pointer=(unsigned char*)_imgPtrVector.at(counter);
    cv::Mat _matrixImage(cv::Size( width,height), CV_8UC1,_pointer , cv::Mat::AUTO_STEP);       
    fs <<"Matrix"<<_matrixImage;
    counter++;
}

但是当我想从同一个文件加载数据时，我遇到了这些错误；这是从存储文件中读取的代码:

cv::FileStorage f("myFile.yaml", cv::FileStorage::READ );
cv::Mat mat(cv::Size( width,height), CV_8UC1);  
if(f.isOpened()){
    cv::FileNode n = f["Matrix"];
    if (n.type() != cv::FileNode::SEQ){
     std::cout << "error!";
    }
    f["Matrix"] >>  mat; 
}

Answer 1

问题可能是您总是附加到现有文件。因此，您可能必须将代码更改为:

FileStorage fs("test.yml", FileStorage::WRITE);

这将在每次程序运行时重新创建文件。

OpenCV 文档在 how to write 上有一个示例非常清楚的 XML/YAML 持久性:

#include "opencv2/opencv.hpp"
#include <time.h>

using namespace cv;

int main(int, char** argv)
{
    FileStorage fs("test.yml", FileStorage::WRITE);

    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();
    return 0;
}

还有另一个例子显示how to read .