title: Crop out part from images (findContours?) {opencv, java}
body: <p>I have this image with boxes containing letters, like this:</p>
  
  <p><img src="https://i.stack.imgur.com/rwp8e.jpg" alt="Original"></p>
  
  <p>I have been able to crop out each box., like this:</p>
  
  <p><img src="https://i.stack.imgur.com/6YneN.jpg" alt="Picture of a cropped box containing a letter">  </p>
  
  <p>Now to my question. How can i crop out the letters only from each box? The desired result looks like this</p>
  
  <p><img src="https://i.stack.imgur.com/HHDuI.jpg" alt="desired result"></p>
  
  <p>I would like to use findContours but I am not really sure of how to achieve this since it will detect the noise and everything around as well.</p>