Subtract 2 Numpy Arrays With Condition

I have two Numpy arrays which look like this: a = [[ [1,2,3], [4,5,6] ], [ [7,8,9], [10,11,12] ]] b = [[ [1,1,1], [0,0,0] ], [ [3,3,3], [4,4,4] ]] I want to perform c

Solution 1:

Use np.where

>>> c = np.where(np.array(b)>0, 255, a)
>>> c
array([[[255, 255, 255],
        [  4,   5,   6]],

       [[255, 255, 255],
        [255, 255, 255]]])

Btw. there is no subtracting happpening here; maybe change the title of your question.