RETR_EXTERNAL 

#include "opencv/cv.h" 
#include "opencv/highgui.h" 
using namespace std; 
using namespace cv; 
 
int main() 
{ 
 
Mat srcimg=imread("./22.jpg"); 
Mat dst; 
cvtColor(srcimg,dst,CV_BGR2GRAY); 
threshold(dst,dst,120,255,1); 
vector<vector<Point> > edgepoint; 
vector<Vec4i> lclass; 
 
findContours(dst,edgepoint,lclass,RETR_EXTERNAL,CHAIN_APPROX_NONE,Point()); 
Mat mat[edgepoint.size()]; 
 
for(int i=0;i<edgepoint.size();i++) 
{ 
  
 Rect rec=boundingRect(Mat(edgepoint[i])); 
 mat[i]=dst(rec);  
rectangle(dst,rec,Scalar(100,80,90),1,1,0);  
 drawContours(dst,edgepoint,i,Scalar(200),1,8,lclass); 
 string str=to_string(i); 
 imshow(str,mat[i]); 
 
} 
imshow("tt",dst); 
cout<<edgepoint.size()<<endl; 
waitKey(0); 
 
}