converted some more samples to C++

samples/cpp/fitellipse.cpp

@@ -0,0 +1,83 @@
+/********************************************************************************
+*
+*
+*  This program is demonstration for ellipse fitting. Program finds
+*  contours and approximate it by ellipses.
+*
+*  Trackbar specify threshold parametr.
+*
+*  White lines is contours. Red lines is fitting ellipses.
+*
+*
+*  Autor:  Denis Burenkov.
+*
+*
+*
+********************************************************************************/
+#include "opencv2/imgproc/imgproc.hpp"
+#include "opencv2/highgui/highgui.hpp"
+
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+int sliderPos = 70;
+
+Mat image;
+
+void processImage(int, void*);
+
+int main( int argc, char** argv )
+{
+    const char* filename = argc == 2 ? argv[1] : (char*)"stuff.jpg";
+    image = imread(filename, 0);
+    if( image.empty() )
+    {
+        cout << "Usage: fitellipse <image_name>\n";
+        return 0;
+    }
+
+    imshow("source", image);
+    namedWindow("result", 1);
+    
+    // Create toolbars. HighGUI use.
+    createTrackbar( "threshold", "result", &sliderPos, 255, processImage );
+    processImage(0, 0);
+
+    // Wait for a key stroke; the same function arranges events processing
+    waitKey();
+    return 0;
+}
+
+// Define trackbar callback functon. This function find contours,
+// draw it and approximate it by ellipses.
+void processImage(int h, void*)
+{
+    vector<vector<Point> > contours;
+    Mat bimage = image >= sliderPos;
+    
+    findContours(bimage, contours, CV_RETR_LIST, CV_CHAIN_APPROX_NONE);
+
+    Mat cimage = Mat::zeros(bimage.size(), CV_8UC3);
+
+    for(size_t i = 0; i < contours.size(); i++)
+    {
+        size_t count = contours[i].size();
+        if( count < 6 )
+            continue;
+        
+        Mat pointsf;
+        Mat(contours[i]).convertTo(pointsf, CV_32F);
+        RotatedRect box = fitEllipse(pointsf);
+        
+        box.angle = -box.angle;
+        if( MAX(box.size.width, box.size.height) > MIN(box.size.width, box.size.height)*30 )
+            continue;
+        drawContours(cimage, contours, (int)i, Scalar::all(255), 1, 8);
+
+        ellipse(cimage, box, Scalar(0,0,255), 1, CV_AA);
+    }
+
+    imshow("result", cimage);
+}