Just using javascript from two years ago: <a href="http://facedetection.jaysalvat.com/" rel="nofollow">http://facedetection.jaysalvat.com/</a> (hn comments: <a href="http://news.ycombinator.com/item?id=2002316" rel="nofollow">http://news.ycombinator.com/item?id=2002316</a>)
Seems to me you could have just had Jetty/OpenCV send back the coords of the faces, then have Javascript draw a box around them. Would have saved quite a bit of bandwidth and removed the need for experimental APIs.
Try this version too: <a href="http://neave.com/webcam/html5/face/" rel="nofollow">http://neave.com/webcam/html5/face/</a><p>It doesn't require WebSockets or Jetty. Just good ol' JavaScript/HTML5. Nothing more.
s/HTML5/HTML-ng/<p>Just because HTML5 != work in every HTML5 browser.
"Numbers don't mean anything anymore they say". Well for HTML5 thats pretty much spot on.. and that's unfortunate.<p>The demo's cool tho :)