title: How to detect if a frame is odd or even on an interlaced image?
body: <p>I have a device that is taking TV screenshots at precise times (it doesn't take incomplete frames). </p>
  
  <p>Still this screenshot is an interlace image made from two different original frames.</p>
  
  <p>Now, the question is if/how is possible to identify which of the lines are newer/older.</p>
  
  <p>I have to mention that I can take several sequential screenshots if needed.</p>
  
  <p><img src="https://i.stack.imgur.com/Drl50.gif" alt="enter image description here"></p>