Hello friendos!
How may I get the value of a subtraction between two images? It can definitely display the difference, since there is even an output image which shows which parts of the picture is different from another.
I would appreciate your kind intellect to assist me 
please show, what you tried so far
The value is a matrix, which you can view as a image, but obviously you could print out the values as well (though a million numbers in a listing is challenging for humans to interpret), or figure out some summary function that suits your goals, and make do with outputting one number.
Super simply explained this code takes two images (and removes most of the pictures colours, since I’m mostly interested in shapes) and subtracts them from each other 
import cv2
ix = cv2.imread("test/default1.jpg")
iy = cv2.imread("test/default1_edited.jpg")
gx = cv2.cvtColor(ix, cv2.COLOR_BGR2GRAY)
gy = cv2.cvtColor(iy, cv2.COLOR_BGR2GRAY)
tmin = 192
tmax = 255
_, tx = cv2.threshold(-gx, tmin, tmax, cv2.THRESH_BINARY)
_, ty = cv2.threshold(-gy, tmin, tmax, cv2.THRESH_BINARY)
sb = tx - ty
out = sb
while True:
cv2.imshow("Output :)", out)
key = cv2.waitKey(1) & 0xFF
if key == ord("q"):
break
Here are the two images, for reference:
Of course, you might want the output, and I got you 
here you go:
Please excuse my late reply, I had some technical difficulties 
You’re so right! I’ve tried with something like this, however with no luck but what you said will be useful I need to make a “summary function” somehow if there is not a way to do this Thank you so much for the help 
you have to be careful with numpy arrays, some operations may lead to unexpected results, like:
a = np.array([3,1,7], np.uint8)
b = np.array([7,1,9], np.uint8)
print(a-b)
[252 0 254]
(it does not truncate, but “wraps around” !)
maybe you want to use absdiff() instead
Thank you so much for the info! Can you help me about how may I use absdiff in this situation? Tried making a material, but it didn’t return anything
absdiff will take the absolute difference or subtraction without signs:
absdiff(imageA, imageB, result)
imshow(“Results of difference”, result)
this is C++ format, Python may just return “result”… try and see.