import cv2
import numpy as np
a=cv2.imread('lenacolor.png',flags=cv2.IMREAD_UNCHANGED)#cv2.IMREAD_UNCHANGED 未改变
b = a
result1 = a + b
result2 = cv2.add(a, b)
cv2.imshow("original", a)
cv2.imshow("result1", result1)
cv2.imshow("result2", result2)
cv2.waitKey(0)
cv2.destroyAllWindows()

import cv2
b=cv2.imread('lena.bmp')#cv2.IMREAD_UNCHANGED 未改变
a=cv2.imread("boat.bmp")
result=cv2.addWeighted(a,1,b,1,0)
cv2.imshow("boat",a)
cv2.imshow("lena",b)
cv2.imshow("result",result)
cv2.waitKey()
cv2.destroyAllWindows()