title: Chroma key removal algorithm/library
body: <p>I am working on a recorder software for desktop PC that works on Windows XP/7.  I would like to be able to remove backgrounds from the recorded video by means of chroma keying.</p>
  <p><a href="https://i.stack.imgur.com/IvnNJ.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IvnNJ.jpg" alt="Example" /></a><br />
  <sub>(source: <a href="http://www.kudlian.net/products/screen/images/0002-large.jpg" rel="nofollow noreferrer">kudlian.net</a>)</sub></p>
  <p>Any info of such algorithms, complete libraries, open source projects?  I need it to be accessible from c#, and preferably something that will run on GPUs (CUDA, pixel shaders, ...)</p>
  <p>My video is accessible in RGB24 and YUY2 formats, so it would be great if such library will be able to handle those formats.</p>