Add Java and Python code for the following imgproc tutorials: Finding contours in your image, Convex Hull, Creating Bounding boxes and circles for contours, Creating Bounding rotated boxes and ellipses for contours, Image Moments, Point Polygon Test.

samples/cpp/tutorial_code/ShapeDescriptors/hull_demo.cpp

@@ -12,9 +12,8 @@
 using namespace cv;
 using namespace std;
 
-Mat src; Mat src_gray;
+Mat src_gray;
 int thresh = 100;
-int max_thresh = 255;
 RNG rng(12345);
 
 /// Function header
@@ -25,30 +24,31 @@ void thresh_callback(int, void* );
  */
 int main( int argc, char** argv )
 {
-  /// Load source image and convert it to gray
-  CommandLineParser parser( argc, argv, "{@input | ../data/stuff.jpg | input image}" );
-  src = imread( parser.get<String>( "@input" ), IMREAD_COLOR );
-  if( src.empty() )
-  {
-    cout << "Could not open or find the image!\n" << endl;
-    cout << "Usage: " << argv[0] << " <Input image>" << endl;
-    return -1;
-  }
+    /// Load source image and convert it to gray
+    CommandLineParser parser( argc, argv, "{@input | ../data/stuff.jpg | input image}" );
+    Mat src = imread( parser.get<String>( "@input" ) );
+    if( src.empty() )
+    {
+        cout << "Could not open or find the image!\n" << endl;
+        cout << "Usage: " << argv[0] << " <Input image>" << endl;
+        return -1;
+    }
 
-  /// Convert image to gray and blur it
-  cvtColor( src, src_gray, COLOR_BGR2GRAY );
-  blur( src_gray, src_gray, Size(3,3) );
+    /// Convert image to gray and blur it
+    cvtColor( src, src_gray, COLOR_BGR2GRAY );
+    blur( src_gray, src_gray, Size(3,3) );
 
-  /// Create Window
-  const char* source_window = "Source";
-  namedWindow( source_window, WINDOW_AUTOSIZE );
-  imshow( source_window, src );
+    /// Create Window
+    const char* source_window = "Source";
+    namedWindow( source_window );
+    imshow( source_window, src );
 
-  createTrackbar( " Threshold:", "Source", &thresh, max_thresh, thresh_callback );
-  thresh_callback( 0, 0 );
+    const int max_thresh = 255;
+    createTrackbar( "Canny thresh:", source_window, &thresh, max_thresh, thresh_callback );
+    thresh_callback( 0, 0 );
 
-  waitKey(0);
-  return(0);
+    waitKey();
+    return 0;
 }
 
 /**
@@ -56,31 +56,30 @@ int main( int argc, char** argv )
  */
 void thresh_callback(int, void* )
 {
-  Mat threshold_output;
-  vector<vector<Point> > contours;
-  vector<Vec4i> hierarchy;
+    /// Detect edges using Canny
+    Mat canny_output;
+    Canny( src_gray, canny_output, thresh, thresh*2 );
 
-  /// Detect edges using Threshold
-  threshold( src_gray, threshold_output, thresh, 255, THRESH_BINARY );
+    /// Find contours
+    vector<vector<Point> > contours;
+    findContours( canny_output, contours, RETR_TREE, CHAIN_APPROX_SIMPLE );
 
-  /// Find contours
-  findContours( threshold_output, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point(0, 0) );
+    /// Find the convex hull object for each contour
+    vector<vector<Point> >hull( contours.size() );
+    for( size_t i = 0; i < contours.size(); i++ )
+    {
+        convexHull( contours[i], hull[i] );
+    }
 
-  /// Find the convex hull object for each contour
-  vector<vector<Point> >hull( contours.size() );
-  for( size_t i = 0; i < contours.size(); i++ )
-     {   convexHull( contours[i], hull[i], false ); }
+    /// Draw contours + hull results
+    Mat drawing = Mat::zeros( canny_output.size(), CV_8UC3 );
+    for( size_t i = 0; i< contours.size(); i++ )
+    {
+        Scalar color = Scalar( rng.uniform(0, 256), rng.uniform(0,256), rng.uniform(0,256) );
+        drawContours( drawing, contours, (int)i, color );
+        drawContours( drawing, hull, (int)i, color );
+    }
 
-  /// Draw contours + hull results
-  Mat drawing = Mat::zeros( threshold_output.size(), CV_8UC3 );
-  for( size_t i = 0; i< contours.size(); i++ )
-     {
-       Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
-       drawContours( drawing, contours, (int)i, color, 1, 8, vector<Vec4i>(), 0, Point() );
-       drawContours( drawing, hull, (int)i, color, 1, 8, vector<Vec4i>(), 0, Point() );
-     }
-
-  /// Show in a window
-  namedWindow( "Hull demo", WINDOW_AUTOSIZE );
-  imshow( "Hull demo", drawing );
+    /// Show in a window
+    imshow( "Hull demo", drawing );
 }