Numpy remove a dimension from np array

Question

I have some images I want to work with, the problem is that there are two kinds of images both are 106 x 106 pixels, some are in color and some are black and white.

Answer 1

Actually np.delete would work if you would apply it two times, if you want to preserve the first channel for example then you could run the following:

Xtrain = np.delete(Xtrain,2,2) # this will get rid of the 3rd component of the 3 dimensions
print(Xtrain.shape) # will now output (106,106,2)
# again we apply np.delete but on the second component of the 3rd dimension
Xtrain = np.delete(Xtrain,1,2)
print(Xtrain.shape) # will now output (106,106,1)
# you may finally squeeze your output to get a 2d array
Xtrain = Xtrain.squeeze()
print(Xtrain.shape) # will now output (106,106)