python opencv 与matplotlib

import numpy as np
import cv2
import matplotlib.pyplot as plt

#读图
img = cv2.imread('E:\image_0003.jpg')
#b,g,r=cv2.split(img)#分离bgr分量
#img2=cv2.merge([r,g,b])
img2=img[:,:,::-1]
plt.subplot(121);plt.imshow(img)
plt.subplot(122);plt.imshow(img2)#显示正常
plt.show()

cv2.imshow('bgr',img)#显示正常
cv2.imshow('rgb',img2)
k=cv2.waitKey(0)
if k==27:
    cv2.destroyAllWindows()    
elif k==ord('s'):
    cv2.imwrite('sunflower.png',img)
    cv2.destroyAllWindows()