title: Crop Custom Shape in ImageJ or equivalent (TIFF video file)
body: <p>I have a .tiff video file with growing fibers that look like the image below </p>
  
  <p><img src="https://i.stack.imgur.com/x60ly.png" alt="enter image description here"></p>
  
  <p>Now
   imagine that this fiber will constantly grow and shrink in a straight line. Now I'd like to somehow crop out the region of the video that contains just the fiber with, for example, a black background image.</p>
  
  <p><img src="https://i.stack.imgur.com/y7eXS.png" alt="enter image description here"></p>
  
  <p>Now when I play the video I'd like to just see the growing fiber region of the video with the black background everywhere else. </p>
  
  <p><strong>Question: Is there a way to preform a "custom" crop of irregular shaped objects in ImageJ?</strong></p>
  
  <p>If you don't know if ImageJ can do this sort of image processing any other software options are welcome.</p>
  
  <p>Thanks for any help</p>