1 #include "opencv2/highgui/highgui.hpp"
2 #include "opencv2/imgproc/imgproc.hpp"
3
4 #include <iostream>
5
6 using namespace cv;
7 using namespace std;
8
help()9 static void help()
10 {
11 cout << "This program demonstrates finding the minimum enclosing box, triangle or circle of a set\n"
12 << "of points using functions: minAreaRect() minEnclosingTriangle() minEnclosingCircle().\n"
13 << "Random points are generated and then enclosed.\n\n"
14 << "Press ESC, 'q' or 'Q' to exit and any other key to regenerate the set of points.\n\n"
15 << "Call:\n"
16 << "./minarea\n"
17 << "Using OpenCV v" << CV_VERSION << "\n" << endl;
18 }
19
main(int,char **)20 int main( int /*argc*/, char** /*argv*/ )
21 {
22 help();
23
24 Mat img(500, 500, CV_8UC3);
25 RNG& rng = theRNG();
26
27 for(;;)
28 {
29 int i, count = rng.uniform(1, 101);
30 vector<Point> points;
31
32 // Generate a random set of points
33 for( i = 0; i < count; i++ )
34 {
35 Point pt;
36 pt.x = rng.uniform(img.cols/4, img.cols*3/4);
37 pt.y = rng.uniform(img.rows/4, img.rows*3/4);
38
39 points.push_back(pt);
40 }
41
42 // Find the minimum area enclosing bounding box
43 RotatedRect box = minAreaRect(Mat(points));
44
45 // Find the minimum area enclosing triangle
46 vector<Point2f> triangle;
47
48 minEnclosingTriangle(points, triangle);
49
50 // Find the minimum area enclosing circle
51 Point2f center, vtx[4];
52 float radius = 0;
53 minEnclosingCircle(Mat(points), center, radius);
54 box.points(vtx);
55
56 img = Scalar::all(0);
57
58 // Draw the points
59 for( i = 0; i < count; i++ )
60 circle( img, points[i], 3, Scalar(0, 0, 255), FILLED, LINE_AA );
61
62 // Draw the bounding box
63 for( i = 0; i < 4; i++ )
64 line(img, vtx[i], vtx[(i+1)%4], Scalar(0, 255, 0), 1, LINE_AA);
65
66 // Draw the triangle
67 for( i = 0; i < 3; i++ )
68 line(img, triangle[i], triangle[(i+1)%3], Scalar(255, 255, 0), 1, LINE_AA);
69
70 // Draw the circle
71 circle(img, center, cvRound(radius), Scalar(0, 255, 255), 1, LINE_AA);
72
73 imshow( "Rectangle, triangle & circle", img );
74
75 char key = (char)waitKey();
76 if( key == 27 || key == 'q' || key == 'Q' ) // 'ESC'
77 break;
78 }
79
80 return 0;
81 }
82