iOS 11 Vision. Face detection

detect-face-landmarks.swift

import Vision
//1
let sourceImage = UIImage(named: "jony.jpg")
var resultImage = sourceImage
//2
let detectFaceRequest = VNDetectFaceLandmarksRequest { (request, error) in
  //4
  if let results = request.results as? [VNFaceObservation] {
    //5
    for faceObservation in results {
      //6
      guard let landmarks = faceObservation.landmarks else {
          continue
      }
      let boundingRect = faceObservation.boundingBox
      var landmarkRegions: [VNFaceLandmarkRegion2D] = []
      //7
      if let faceContour = landmarks.faceContour {
          landmarkRegions.append(faceContour)
      }
      //8
      resultImage = self.drawOnImage(source: resultImage, boundingRect: boundingRect, faceLandmarkRegions: landmarkRegions)
    }
  }
}
//3
let vnImage = VNImageRequestHandler(cgImage: sourceImage.cgImage!, options: [:])
try? vnImage.perform([detectFaceRequest])