title: detect blob over other blob
body: <p>I use OpenCV and cvblob library to play with blob.</p>
  
  <p>Now I want to detect blob in this particular case.</p>
  
  <p>The problem or the difficulty in this case is there are two blobs over a bigger one and other blob that overlap a part of the bigger one.</p>
  
  <p>In cvblob library to detect a blob you must have a binary image. </p>
  
  <p>I think i need to create two or more image to segment color uniform blobs and then binarize them to obtain all the blobs in the image.</p>
  
  <p>How can i do that.</p>
  
  <p><img src="https://i.stack.imgur.com/oWfKP.jpg" alt="Image"></p>
  
  <p>thanks in advance</p>