OpenCV Python图像冲洗

If you wish to add both images into one (so they both appear on the resulting image), with each one of the inputs averaged, you should use the addWeighted() method, like this (taken from the docs):

import numpy as np
import cv2

#load your images
dolphin = cv2.imread('dolphin.png') #use 0 for grayscale
bicycle = cv2.imread('bicycle.png') 
#add them with a weight, respectively, last parameter is a scalar added 
dst = cv2.addWeighted(dolphin,0.7,bicycle,0.3,0) 

#show
cv2.imshow('Blended Image',dst)
cv2.waitKey(0)
cv2.destroyAllWindows()

Note: As also mentioned in the previous link, it is important to notice that numpy and OpenCV addition are different, as numpy has a modulo operation (%) while OpenCV has a saturated operation (caps at a maximum), to clarify we have this extracted example from that link:

>>> x = np.uint8([250])
>>> y = np.uint8([10])

>>> print( cv2.add(x,y) ) # 250+10 = 260 => 255 , saturated
[[255]]
>>> print( x+y )          # 250+10 = 260 % 256 = 4 , modulo
[4]

这可能是为什么您改用add()方法获得白色图像的原因（所有像素上限为255，并显示白色）。