title: Is Picture-in-Picture possible using OpenCV?
body: <p>I would like to add a smaller image on top of a larger image (eventually for PiP on a video feed). I can do it by iterating through the relevant data property in the large image and add the pixels from the small image. But is there a simpler and neater way? I'm using EMGU.</p>
  
  <p>My idea was to define an ROI in the large image of the same size as the small image. Set the Large image equal to the small image and then simply remove the ROI. Ie in pseudo code:</p>
  
  <pre><code>Large.ROI = rectangle defined by small image;
  
  Large = Small;
  
  Large.ROI = Rectangle.Empty;
  </code></pre>
  
  <p>However this doesn't work and the large image doesn't change. Any suggestions would be much appreciated.</p>
  
  <p>Large image:<br>
  <img src="https://i.stack.imgur.com/NbI7o.png" alt="Large Image"></p>
  
  <p>Small image:<br>
  <img src="https://i.stack.imgur.com/PLKUI.png" alt="Small Image"></p>
  
  <p>Desired result:<br>
  <img src="https://i.stack.imgur.com/hdKi4.png" alt="Desired Result"></p>