jupyter notebook oepncv 显示一张图像的实现

import os
import numpy as np
from matplotlib import pyplot as plt
%matplotlib inline
img_dir='/Users/eric/Documents/data/wheel_train_val/train/non_defect/'
filename='00005.BMP_block_8.jpg'
img = cv2.imread(img_dir +os.sep+ filename)
plt.imshow(img)
plt.show()

cap = cv2.VideoCapture(0)
while(1):
  # get a frame
  ret,frame = cap.read()
  # show a frame
  cv2.imshow("capture", frame)
  if cv2.waitKey(1) & 0xFF == ord('q'):
    cv2.imwrite("./test.jpeg", frame)
    break
cap.release()
cv2.destroyAllWindows()