title: Find circles in image without using Hough transform
body: <p>I want to find the circles in the below image.I tried using OpenCV's <a href="http://docs.opencv.org/doc/tutorials/imgproc/imgtrans/hough_circle/hough_circle.html" rel="nofollow noreferrer">Hough circle detection</a> but it is not giving the proper results.</p>
  
  <p>Is there any other way to find circles?</p>
  
  <p><img src="https://i.stack.imgur.com/XwCZu.png" alt="enter image description here"></p>
  
  <p>Here is sample code </p>
  
  <pre><code>vector&lt;Vec3f&gt; circles;
  Mat src_gray,te; 
  cvtColor(tImg, src_gray, CV_BGR2GRAY);
  GaussianBlur(src_gray, src_gray, Size(9, 9), 2, 2);
  Canny(src_gray, te, 40, 240, 3);
  /// Apply the Hough Transform to find the circles 
  HoughCircles(te, circles, CV_HOUGH_GRADIENT, 1, te.rows / 10, 120, 9, 5, 25); 
  </code></pre>