title: Determining the pattern orientation of a spatiotemporal image
body: <p>How can I obtain average direction of the pattern shown in the figure below. It is the direction of the red arrow relative to the yellow (horizontal) line. Any ideas for an approach? I couldn't figure out a way to approach. This is a spatio-temporal image created from a video. Thank you.</p>
  
  <p><a href="https://i.stack.imgur.com/QtApq.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QtApq.jpg" alt="Figure A"></a></p>
  
  <p>Here is my original image:<a href="https://i.stack.imgur.com/IxoVk.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IxoVk.jpg" alt="enter image description here"></a></p>