TypeError：src不是一个numpy数组，也不是一个标量：Recognitor.train（）中的错误

Question

我收到此错误：

Traceback (most recent call last):

  File "<ipython-input-1-cf0ff588e2e2>", line 1, in <module>
    runfile('E:/FaceDetection/face_recognition.py', wdir='E:/FaceDetection')

  File "C:\Users\varun\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 705, in runfile
    execfile(filename, namespace)

  File "C:\Users\varun\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 102, in execfile
    exec(compile(f.read(), filename, 'exec'), namespace)

  File "E:/FaceDetection/face_recognition.py", line 43, in <module>
    recognizer.train(x_train, np.array(y_labels))

TypeError: src is not a numpy array, neither a scalar

---

对于我的源代码：

import cv2
import os
import numpy as np
from PIL import Image
import pickle

BASE_DIR = os.path.dirname(os.path.abspath(__file__))
image_dir = os.path.join(BASE_DIR, "Images")

face_cascade = cv2.CascadeClassifier('Haar\haarcascade_frontalcatface.xml')
recognizer = cv2.face.LBPHFaceRecognizer_create()

current_id = 0
label_id = {}

y_labels = []
x_train = []
for root, dirs, files in os.walk(image_dir):
  for file in files:
    if file.endswith("png") or file.endswith("jpg"):
      path = os.path.join(root, file)
      label = os.path.basename(root).replace(" ", "-").lower()
      #print (label, path)
      if not label in label_id:
        label_id[label] = current_id
        current_id += 1

      idee = label_id[label]
      #print(label_id)
      y_labels.append(label)
      x_train.append(path)
      pil_image = Image.open(path).convert("L")
      image_array = np.array(pil_image, 'uint8')
      faces = face_cascade.detectMultiScale(image_array, scaleFactor = 1.03 ,minNeighbors = 5)
      for(x, y, w, h) in faces:
        roi = image_array[y:y+h, x:x+w]
        x_train.append(roi)
        y_labels.append(idee)
with open("labels.pickle", 'wb') as f:
  pickle.dump(label_id, f)

recognizer.train(x_train, np.array(y_labels))
recognizer.save("trainner.yml")

我该如何解决？为什么我会收到此错误？