IOS CoreImage Facial Detection at All Orientations

Question

I am using CoreImage on IOS to detect faces in an image. It works fine when there are multiple faces, but doesn't work for simple faces such as this one:

The face is really big and obvious, but CoreImage cannot detect it. I'm thinking it may be because of my kCGImagePropertyOrientation.

I set it to 5, simply because that's what an online tutorial did. However, the images which I am processing are user uploaded, so I do not know the orientation of the face beforehand. Is there a way to try all orientations? What is the proper way of implementing CoreImage facial detection when the images are not known before hand?

This is my code:

var imageOptions = Dictionary<String,Any>()
imageOptions[CIDetectorImageOrientation] = 5
imageOptions[CIDetectorSmile] = true

let image = CIImage(cgImage: imageView.image!.cgImage!)
let accuracy = [CIDetectorAccuracy: CIDetectorAccuracyHigh]

let faceDetector = CIDetector(ofType: CIDetectorTypeFace, context: nil, options: accuracy)
let faces = faceDetector?.features(in: image, options: imageOptions as? [String : AnyObject])

Answer 1

You can do it like this

   var imageOrienttion = 0
   switch (YourUIImage.imageOrientation) {
    case UIImageOrientation.up:
        imageOrienttion = 1
        break;
    case UIImageOrientation.down:
        imageOrienttion = 3
        break;
    case UIImageOrientation.left:
        imageOrienttion = 8
        break;
    case UIImageOrientation.right:
        imageOrienttion = 6
        break;
    case UIImageOrientation.upMirrored:
        imageOrienttion = 2
        break;
    case UIImageOrientation.downMirrored:
        imageOrienttion = 4
        break;
    case UIImageOrientation.leftMirrored:
        imageOrienttion = 5
        break;
    case UIImageOrientation.rightMirrored:
        imageOrienttion = 7
        break;
   }
   imageOptions[CIDetectorImageOrientation] = imageOrienttion