CIFaceFeature只檢測一張臉

Question

問題是我的代碼只能用於一張臉。如果我拍了兩張臉的照片，它不會檢測到第二張臉，而對於兩張以上的臉也是如此。這裏是我的代碼：

if let inputImage = imageView.image { 
     let ciImage = CIImage(CGImage: inputImage.CGImage!) 

     let options = [CIDetectorAccuracy: CIDetectorAccuracyHigh] 
     let faceDetector = CIDetector(ofType: CIDetectorTypeFace, context: nil, options: options) 

     let faces = faceDetector.featuresInImage(ciImage) 

     if let face = faces.first as? CIFaceFeature { 
      print("Found face at \(face.bounds)") 

      if face.hasLeftEyePosition { 
       print("Found left eye at \(face.leftEyePosition)") 
      } 

      if face.hasRightEyePosition { 
       print("Found right eye at \(face.rightEyePosition)") 
      } 

      if face.hasMouthPosition { 
       print("Found mouth at \(face.mouthPosition)") 
      } 
     } 
     print("\(faces.count)") 
    } 

Answer 1

您的問題是，你只上發現的第一面的工作，因爲這一點：

if let face = faces.first as? CIFaceFeature { 

---

因此，例如，相反，你可以使用一個循環和迭代這個數組，像這樣：

for item in faces { 
    if let face = item as? CIFaceFeature { 
     print("Found face at \(face.bounds)") 

     if face.hasLeftEyePosition { 
      print("Found left eye at \(face.leftEyePosition)") 
     } 

     if face.hasRightEyePosition { 
      print("Found right eye at \(face.rightEyePosition)") 
     } 

     if face.hasMouthPosition { 
      print("Found mouth at \(face.mouthPosition)") 
     } 
    } 
} 

還是這個樣子，稍微好一點：

if let faces = faceDetector.featuresInImage(ciImage) as? [CIFaceFeature] { 
    for face in faces { 
     print("Found face at \(face.bounds)") 

     if face.hasLeftEyePosition { 
      print("Found left eye at \(face.leftEyePosition)") 
     } 

     if face.hasRightEyePosition { 
      print("Found right eye at \(face.rightEyePosition)") 
     } 

     if face.hasMouthPosition { 
      print("Found mouth at \(face.mouthPosition)") 
     } 
    } 
}