Python ndarray padding__Python

Python ndarray padding

With the bug about np.lib.pad reported here: https://github.com/numpy/numpy/issues/7353 and the corresponding update here: https://github.com/numpy/numpy/pull/7354#issuecomment-189551370

We can get the proper padding for ndarray. 

Demo code:

import numpy as npimport cv2T = np.ones([150, 100, 200], dtype='uint8')T = T*200P = np.lib.pad(T, ((50, 50),(50, 50),(50, 50)), 'constant', constant_values=np.array(((100, 100),(100, 100),(100, 100))))dim  = P.shapeprint dimfor k in range(dim[2]):    cv2.imshow('slice', P[:, :, k])    cv2.waitKey(20)