利用OpenCV求取圖像多輪廓質心，並在輸出圖像上顯示質心座標

1、源代碼

#include "stdafx.h"
#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv/cv.hpp>
#include <opencv2/highgui/highgui.hpp>

using namespace cv; 
using namespace std; 
Mat src; 
Mat src_gray; 
int thresh = 30; 
int max_thresh = 255; 

int main()
{ 	
	src = imread( "C:\\Users\\Lijunliang\\Desktop\\opencvpic\\2\\22.png" ,CV_LOAD_IMAGE_COLOR ); 	//注意路徑得換成自己的
	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) ); //濾波 	
	namedWindow( "image", CV_WINDOW_AUTOSIZE ); 	
	imshow( "image", src ); 	
	moveWindow("image",20,20); 	
	//定義Canny邊緣檢測圖像 	
	Mat canny_output; 	
	vector<vector<Point> > contours; 	
	vector<Vec4i> hierarchy; 	
	//利用canny算法檢測邊緣 	
	Canny( src_gray, canny_output, thresh, thresh*3, 3 ); 	
	namedWindow( "canny", CV_WINDOW_AUTOSIZE ); 	
	imshow( "canny", canny_output ); 	
	moveWindow("canny",550,20); 	
	//查找輪廓 	
	findContours( canny_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) ); 	
	//計算輪廓矩 	
	vector<Moments> mu(contours.size() ); 	
	for( int i = 0; i < contours.size(); i++ ) 	
	{ 
		mu[i] = moments( contours[i], false ); 
	} 	
	//計算輪廓的質心 	
	vector<Point2f> 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 ); 
	}  	
	//畫輪廓及其質心並顯示 	
	Mat drawing = Mat::zeros( canny_output.size(), CV_8UC3 ); 		
	for( 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; 
}

2、獲取實驗結果