Easy use CIDetector.

FaceDetector.swift

//
//  FaceDetector.swift
//
//  Created by Tomoya Hirano on 2016/05/21.
//  Copyright © 2016年 Tomoya Hirano. All rights reserved.
//

import UIKit

struct Face {
  private(set) var rect: CGRect!
  private(set) var mouth: CGPoint? = nil
  private(set) var leftEye: CGPoint? = nil
  private(set) var leftEyeClosed = false
  private(set) var rightEye: CGPoint? = nil
  private(set) var rightEyeClosed = false
  
  private(set) var hasSmile = false
  private(set) var faceAngle: Float? = nil
  private(set) var knownPerson = false
  
  var hasMouth:    Bool  { return mouth    != nil }
  var hasLeftEye:  Bool  { return leftEye  != nil }
  var hasRightEye: Bool { return  rightEye != nil }
  
  init(faceRect: CGRect) {
    self.rect = faceRect
  }
}

final class FaceDetector {
  
  private let ciDetector = CIDetector(ofType:CIDetectorTypeFace,
                              context:nil,
                              options:[
                                CIDetectorAccuracy:CIDetectorAccuracyHigh,
                                CIDetectorSmile:true])
  
  //顔認識情報を使いやすくして入れる
  func detect(image: UIImage) -> [Face] {
    
    let ciimage = CIImage(CGImage: image.CGImage!)
    let featues = ciDetector.featuresInImage(ciimage)
    let imageSize = image.size
    
    return featues.filter { $0 is CIFaceFeature }.map { feature -> Face in
      let feature = feature as! CIFaceFeature
      let faceRect = convertRect(imageSize, rect: feature.bounds)
      var face = Face(faceRect: faceRect)
      if feature.hasMouthPosition {
        face.mouth = convertPoint(imageSize, point: feature.mouthPosition)
      }
      if feature.hasFaceAngle {
        face.faceAngle = feature.faceAngle
      }
      if feature.hasLeftEyePosition {
        face.leftEye =  convertPoint(imageSize, point: feature.leftEyePosition)
      }
      if feature.hasRightEyePosition {
        face.rightEye = convertPoint(imageSize, point: feature.rightEyePosition)
      }
      
      face.leftEyeClosed = feature.leftEyeClosed
      face.rightEyeClosed = feature.rightEyeClosed
      face.knownPerson = feature.hasTrackingID
      face.hasSmile = feature.hasSmile
      
      return face
    }
  }
  
  //位置の確認用
  class func displayDetectedPosition(sourceImage: UIImage, faces: [Face]) -> UIImage {
    let makeRect = {(point: CGPoint) -> CGRect in
      var point = point
      let baseWidth: CGFloat = 10.0
      point.x = point.x - (baseWidth / 2.0)
      point.y = point.y - (baseWidth / 2.0)
      return CGRect(origin: point, size: CGSize(width: baseWidth, height: baseWidth))
    }
    var rects = Array<CGRect>()
    faces.forEach{
      rects.append($0.rect)
      if let p = $0.mouth { rects.append(makeRect(p)) }
      if let p = $0.leftEye { rects.append(makeRect(p)) }
      if let p = $0.rightEye { rects.append(makeRect(p)) }
    }
    return testOverlay(sourceImage, rects: rects)
  }
  
  //四角を描画テスト
  private class func testOverlay(before: UIImage, rects: [CGRect]) -> UIImage {
    var after = UIImage()
    UIGraphicsBeginImageContextWithOptions(before.size, false, 1.0)
    let context = UIGraphicsGetCurrentContext()
    before.drawInRect(CGRect(origin: CGPointZero, size: before.size))
    CGContextSetStrokeColorWithColor(context, UIColor.redColor().CGColor)
    CGContextSetLineWidth(context, 2.0)
    for rect in rects {
      CGContextStrokeRect(context, rect)
    }
    after = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return after
  }
  
  //CIDetector座標を普通の座標に変換
  private func convertRect(size: CGSize, rect: CGRect) -> CGRect {
    var rect = rect
    rect.origin.y = size.height - rect.origin.y - rect.height
    return rect
  }
  
  //CIDetector座標を普通の座標に変換
  private func convertPoint(size: CGSize, point: CGPoint) -> CGPoint {
    var point = point
    point.y = size.height - point.y
    return point
  }
  
}

pretty cool