imread返回NoneType


folder_path = 'fruit81_split/train/西瓜'
# 可视化图像的个数
N = 36

images = []
for each_img in os.listdir(folder_path)[:N]:
    img_path = os.path.join(folder_path, each_img)
    img_bgr = cv2.imread(img_path)
    img_rgb = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2RGB)
    images.append(img_rgb)
---------------------------------------------------------------------------
error                                     Traceback (most recent call last)
Cell In[16], line 6
      4     img_path = "./" + folder_path + "/" + each_img
      5     img_bgr = cv2.imread(img_path)
----> 6     img_rgb = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2RGB)
      7     images.append(img_rgb)
      8 print(each_img)

error: OpenCV(4.8.0) D:\a\opencv-python\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

改用plt.imread。
https://stackoverflow.com/questions/54265107/cv2-imread-returns-none
https://stackoverflow.com/questions/36847433/cv2-imread-does-not-read-jpg-files