opencv | 计算轮廓的质心

#include   
#include   
#include   
#include   
  
using namespace cv;   
using namespace std;   
Mat src;   
Mat src_gray;   
int thresh = 30;   
int max_thresh = 255;   
  
int main()  
{     
    src = imread( "2.jpg" ,CV_LOAD_IMAGE_COLOR );  
    cvtColor( src, src_gray, CV_BGR2GRAY );//灰度化      
    GaussianBlur( src, src, Size(3,3), 0.1, 0, BORDER_DEFAULT );      
    blur( src_gray, src_gray, Size(3,3) ); //滤波       
    namedWindow( "image", CV_WINDOW_AUTOSIZE );       
    imshow( "image", src );       
    moveWindow("image",20,20);    
    //定义Canny边缘检测图像       
    Mat canny_output;     
    vector > contours;      
    vector hierarchy;    
    //利用canny算法检测边缘       
    Canny( src_gray, canny_output, thresh, thresh*3, 3 );     
    namedWindow( "canny", CV_WINDOW_AUTOSIZE );       
    imshow( "canny", canny_output );      
    moveWindow("canny",550,20);       
    //查找轮廓    
    findContours( canny_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );     
    //计算轮廓矩       
    vector mu(contours.size() );       
    for( int i = 0; i < contours.size(); i++ )     
    {   
        mu[i] = moments( contours[i], false );   
    }     
    //计算轮廓的质心     
    vector mc( contours.size() );      
    for( int i = 0; i < contours.size(); i++ )     
    {   
        mc[i] = Point2d( mu[i].m10/mu[i].m00 , mu[i].m01/mu[i].m00 );   
    }     
    //画轮廓及其质心并显示      
    Mat drawing = Mat::zeros( canny_output.size(), CV_8UC3 );         
    for( unsigned int i = 0; i< contours.size(); i++ )      
    {         
        Scalar color = Scalar( 255, 0, 0);        
        drawContours( drawing, contours, i, color, 2, 8, hierarchy, 0, Point() );         
        circle( drawing, mc[i], 5, Scalar( 0, 0, 255), -1, 8, 0 );                
        rectangle(drawing, boundingRect(contours.at(i)), cvScalar(0,255,0));              
        char tam[100];   
        sprintf(tam, "(%0.0f,%0.0f)",mc[i].x,mc[i].y);   
        putText(drawing, tam, Point(mc[i].x, mc[i].y), FONT_HERSHEY_SIMPLEX, 0.4, cvScalar(255,0,255),1);     
    }     
    namedWindow( "Contours", CV_WINDOW_AUTOSIZE );    
    imshow( "Contours", drawing );    
    moveWindow("Contours",1100,20);       
    waitKey(0);       
    src.release();    
    src_gray.release();       
    return 0;
}