Added reST tutorials for Contours (6 in imgproc) and for Corner Detection (4 in features2D) + links in conf.py

doc/tutorials/imgproc/shapedescriptors/hull/hull.rst

@@ -0,0 +1,118 @@
+.. _hull:
+
+Convex Hull
+***********
+
+Goal
+=====
+
+In this tutorial you will learn how to:
+
+.. container:: enumeratevisibleitemswithsquare
+
+   * Use the OpenCV function :convex_hull:`convexHull <>` 
+
+
+Theory
+======
+
+Code
+====
+
+This tutorial code's is shown lines below. You can also download it from `here <https://code.ros.org/svn/opencv/trunk/opencv/samples/cpp/tutorial_code/ShapeDescriptors/hull_demo.cpp>`_
+
+.. code-block:: cpp 
+
+   #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 );
+   }
+
+
+Explanation
+============
+
+Result
+======
+
+#. Here it is:
+
+   ========== ==========  
+    |Hull_0|   |Hull_1|   
+   ========== ==========   
+
+   .. |Hull_0|  image:: images/Hull_Original_Image.jpg
+                     :height: 300pt
+                     :align: middle
+
+   .. |Hull_1|  image:: images/Hull_Result.jpg
+                     :height: 300pt
+                     :align: middle   
+