Opencv 检测棋盘标定点 例程

 

在相机标定中通常首先需要检测出棋盘标定板上黑白格内角点的位置：

网上的一段cvFindChessboardCorners函数调用代码：

#include <iostream>
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/legacy/legacy.hpp"
using namespace std;
 
 
//by Huang, Haiqiao 25 Jun. 2011, fzyhhq@bift.edu.cn
//http://www.opencv.org.cn/forum/viewtopic.php?f=1&t=14214
 
int main( )
{
    cout<<"Draw Chess OpenCV!"<<endl;  
    char* filename="e:/src2/chess2.bmp";
    IplImage* imgRGB = cvLoadImage(filename,1); 
    IplImage* imgGrey = cvLoadImage(filename,CV_LOAD_IMAGE_GRAYSCALE); 
 
    if (imgGrey==NULL){//image validation
        cout<< "No valid image input."<<endl; 
        char c=getchar();
        return 1;
    } 
 
    //-------find chessboard corners--------------
    int corner_row=12;//沿着行的内角点数//interior number of row corners.(this can be countered by fingers.)
    int corner_col=10;//沿着列的内角点数//interior number of column corners.
    int corner_n=corner_row*corner_col;
    
    CvSize pattern_size=cvSize(corner_row,corner_col);
    CvPoint2D32f* corners=new CvPoint2D32f[corner_n];
    int corner_count;
 
    int found=cvFindChessboardCorners(//returning non-zero means sucess.
        imgGrey,// 8-bit single channel greyscale image.
        pattern_size,//how many INTERIOR corners in each row and column of the chessboard.
        corners,//a pointer to an array where the corner locations can be recorded.
        &corner_count,// optional, if non-NULL, its a point to an integer where the nuber of corners found can be recorded.
        CV_CALIB_CB_ADAPTIVE_THRESH|CV_CALIB_CB_FILTER_QUADS// check page 382-383.
 
        );
     cout<<"corner_count = "<<corner_count;
    //-------Draw the corner pattern-------
    cvDrawChessboardCorners(
        imgRGB,
        pattern_size,
        corners,
        corner_count,
        found
        );
 
    //to summary a bit of findings.
    cout<<endl;
    cout<<"found="<<found<<endl;    
    
    //显示角点的坐标
    //for (int c = 0; c<corner_col; c++)
    //{
    //    cout<<endl;
    //    for (int r = 0; r<corner_row; r++)
    //    {
    //        cout<<"[x="<<corners[c*corner_row+r].x;
    //        cout<<" y="<<corners[c*corner_row+r].y<<"] ";
    //    }
    //}
 
    //cvNamedWindow("Find and Draw ChessBoard", 0 );//窗口大小可调节
    cvShowImage( "Find and Draw ChessBoard", imgRGB );
 
    cvWaitKey(0); 
 
    cvReleaseImage(&imgGrey);
    cvReleaseImage(&imgRGB);
    //cvDestroyWindow("Find and Draw ChessBoard"); 
 
    return 0;
}

 

执行结果图：

 

检测结果存储在corner中，沿着连线的方向，从红色的起始。