一. 实验描述

用OpenCV来进行XML和YAML文件的写入和读取。

二. 实验代码

//XML和YAML文件的写入
class Task11 {
public:
    void deal() {
        FileStorage fs("test.xml",FileStorage::WRITE);
        // FileStorage fs("test.yaml",FileStorage::WRITE);

        fs << "frame_count" << 5;

        time_t rawtime;
        time(&rawtime);
        fs << "time" << asctime(localtime(&rawtime));

        Mat camera_mat = (Mat_<double>(3,3) << 1000,0,320,1000,240,1);
        Mat dist_coeffs = (Mat_<double>(5,1) << 0.1,0.01,-0.001,0);
        fs << "camera_mat" << camera_mat << "dist_coeffs" << dist_coeffs;

        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("生成文件完毕\n");
    }
};

//XML和YAML文件的读取
class Task12 {
public:
    void deal() {
        FileStorage fs("test.xml",FileStorage::READ);
        // FileStorage fs("test.yaml",FileStorage::READ);

        int frame_count = fs["frame_count"]; //bug
        cout << "frame_count: " << frame_count << endl;

        string time;
        fs["time"] >> time;
        cout << "time:" << time << endl;

        Mat camera_mat;
        fs["camera_mat"] >> camera_mat;
        cout << "camera_mat:" << camera_mat << endl;

        Mat dist_coeffs;
        fs["dist_coeffs"] >> dist_coeffs;
        cout << "dist_coeffs:" << dist_coeffs << endl;

        FileNode features = fs["features"];
        FileNodeIterator it = features.begin(),it_end = features.end();

        int idx = 0;
        vector<uchar> ibpval;

        for (; it != it_end; ++it,++idx) {
            cout << "features #" << idx << ":";
            cout << "x=" << (int)(*it)["x"] << ",y=" << (int)(*it)["y"] << ",lbp:(";
            (*it)["lbp"] >> ibpval;

            for (int i = 0; i < ibpval.size(); ++i) {
                cout << " " << (int)ibpval[i];
            }
            cout << ")" << endl;
        }
        fs.release();
    }
};

三. 实验结果

生成的“test.xml”文件

<?xml version="1.0"?>
<opencv_storage>
<frame_count>5</frame_count>
<time>"Sat Aug 27 22:04:44 2016&#x0a;"</time>
<camera_mat type_id="opencv-matrix">
  <rows>3</rows>
  <cols>3</cols>
  <dt>d</dt>
  <data>
    1000. 0. 320. 0. 1000. 240. 0. 0. 1.</data></camera_mat>
<dist_coeffs type_id="opencv-matrix">
  <rows>5</rows>
  <cols>1</cols>
  <dt>d</dt>
  <data>
    1.0000000000000001e-001 1.0000000000000000e-002
    -1.0000000000000000e-003 0. 0.</data></dist_coeffs>
<features>
  <_><x>41</x>
    <y>227</y>
    <lbp>
      0 1 1 1 1 1 0 1</lbp></_>
  <_><x>260</x>
    <y>449</y>
    <lbp>
      0 0 1 1 0 1 1 0</lbp></_>
  <_><x>598</x>
    <y>78</y>
    <lbp>
      0 1 0 0 1 0 1 0</lbp></_></features>
</opencv_storage>

生成的“test.yaml”文件

%YAML:1.0
frame_count: 5
time: "Sat Aug 27 22:03:38 2016\n"
camera_mat: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 1000.,0.,320.,1000.,240.,1. ]
dist_coeffs: !!opencv-matrix
   rows: 5
   cols: 1
   dt: d
   data: [ 1.0000000000000001e-001,1.0000000000000000e-002,-1.0000000000000000e-003,0.,0. ] features:
   - { x:41,y:227,lbp:[ 0,1,1 ] }    - { x:260,y:449,0 ] }    - { x:598,y:78,0 ] }

读取文件效果