Face Detection

gistfile1.m

//Have a UIImage *image

NSDictionary *detectorOptions = [[NSDictionary alloc] initWithObjectsAndKeys:CIDetectorAccuracyHigh, CIDetectorAccuracy, nil];

CIDetector *faceDetector = [CIDetector detectorOfType:CIDetectorTypeFace context:nil options:detectorOptions];

CIImage *ciImage = [CIImage imageWithCGImage:[image CGImage]];

NSArray *features = [faceDetector featuresInImage:ciImage];

// features.count == 0 No faces
// features.count == 1 One face.
// features.count > 1 More than one :)