--- /dev/null
+/**
+ * @function hull_demo.cpp
+ * @brief Demo code to find contours in an image
+ * @author OpenCV team
+ */
+
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+#include <iostream>
+#include <stdio.h>
+#include <stdlib.h>
+
+using namespace cv;
+using namespace std;
+
+Mat src; Mat src_gray;
+int thresh = 100;
+int max_thresh = 255;
+RNG rng(12345);
+
+/// Function header
+void thresh_callback(int, void* );
+
+/**
+ * @function main
+ */
+int main( int argc, char** argv )
+{
+ /// Load source image and convert it to gray
+ src = imread( argv[1], 1 );
+
+ /// Convert image to gray and blur it
+ cvtColor( src, src_gray, CV_BGR2GRAY );
+ blur( src_gray, src_gray, Size(3,3) );
+
+ /// Create Window
+ char* source_window = "Source";
+ namedWindow( source_window, CV_WINDOW_AUTOSIZE );
+ imshow( source_window, src );
+
+ createTrackbar( " Threshold:", "Source", &thresh, max_thresh, thresh_callback );
+ thresh_callback( 0, 0 );
+
+ waitKey(0);
+ return(0);
+}
+
+/**
+ * @function thresh_callback
+ */
+void thresh_callback(int, void* )
+{
+ Mat src_copy = src.clone();
+ Mat threshold_output;
+ vector<vector<Point> > contours;
+ vector<Vec4i> hierarchy;
+
+ /// Detect edges using Threshold
+ threshold( src_gray, threshold_output, thresh, 255, THRESH_BINARY );
+
+ /// Find contours
+ findContours( threshold_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );
+
+ /// Find the convex hull object for each contour
+ vector<vector<Point> >hull( contours.size() );
+ for( int i = 0; i < contours.size(); i++ )
+ { convexHull( Mat(contours[i]), hull[i], false ); }
+
+ /// Draw contours + hull results
+ Mat drawing = Mat::zeros( threshold_output.size(), CV_8UC3 );
+ for( int i = 0; i< contours.size(); i++ )
+ {
+ Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
+ drawContours( drawing, contours, i, color, 1, 8, vector<Vec4i>(), 0, Point() );
+ drawContours( drawing, hull, i, color, 1, 8, vector<Vec4i>(), 0, Point() );
+ }
+
+ /// Show in a window
+ namedWindow( "Hull demo", CV_WINDOW_AUTOSIZE );
+ imshow( "Hull demo", drawing );
+}