Is there an example of FaceDetection?

I have just purchased U3DXT mainly to get facedetection working from a camera in the unity scene (Vuforia AR camera). Are there any examples on how to use the high level API for FaceDetection as the documentation isn't available yet.

edit-- I think I am progressing. I'm just reading pixels from the entire screen for now, and here is my code:

 Texture2D newTex = new Texture2D(Screen.width, Screen.height, TextureFormat.RGB24, false);
 newTex.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0);
 newTex.Apply();
 Debug.Log (newTex.width);
 CIDetector det = new CIDetector();
 System.Collections.Generic.Dictionary<object, object> dictionary = new System.Collections.Generic.Dictionary<object, object>();
 dictionary.Add(CIDetector.Accuracy, CIDetector.AccuracyLow);
 det = CIDetector.DetectorOfType (CIDetector.TypeFace,null, dictionary);
 CIImage cimage = new CIImage();
 cimage = CIImage.FromTexture2D(newTex);
 object[] features = det.FeaturesInImage(cimage);
 Debug.Log ("Features: " + features.Length);

It runs fine (though obviously very slow), but features is always of length 0