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#include "cv.h"
#include "highgui.h"
using namespace cv;
Mat img;
int threshval = 100;
void on_trackbar(int, void*)
{
Mat bw = threshval < 128 ? (img < threshval) : (img > threshval);
vector<vector<Point> > contours;
vector<Vec4i> hierarchy;
findContours( bw, contours, hierarchy, CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE );
Mat dst = Mat::zeros(img.size(), CV_8UC3);
if( contours.size() > 0 )
{
// iterate through all the top-level contours,
// draw each connected component with its own random color
int idx = 0;
for( ; idx >= 0; idx = hierarchy[idx][0] )
{
Scalar color( (rand()&255), (rand()&255), (rand()&255) );
drawContours( dst, contours, idx, color, CV_FILLED, 8, hierarchy );
}
}
imshow( "Connected Components", dst );
}
int main( int argc, char** argv )
{
// the first command line parameter must be file name of binary
// (black-n-white) image
if( !(img=imread(argc == 2 ? argv[1] : "stuff.jpg", 0)).data)
return -1;
namedWindow( "Image", 1 );
imshow( "Image", img );
namedWindow( "Connected Components", 1 );
createTrackbar( "Threshold", "Connected Components", &threshval, 255, on_trackbar );
on_trackbar(threshval, 0);
waitKey(0);
return 0;
}