title: OpenCV cropping image
body: <p>I have a image which contains white clusters on black background. The clusters of white portions are not joined together, however I want to draw a contour around entire enclosure instead of around each cluster. The image is attached. </p>
  
  <p>When i tried to form contour it does it around individual cluster. Can I get some tip, help, or code on how to form one general contour.<img src="https://i.stack.imgur.com/N8MRH.jpg" alt="enter image description here"></p>