Вы можете использовать tile
:
In [1]: import numpy as np
In [2]: img = np.ones((150, 150, 1))
In [3]: new = np.tile(img, 3)
In [4]: new.shape
Out[4]: (150, 150, 3)
Например, если img
было:
array([[[1],
[2],
[3]],
[[4],
[5],
[6]],
[[7],
[8],
[9]]])
np.tile(img, 3)
будет:
array([[[1, 1, 1],
[2, 2, 2],
[3, 3, 3]],
[[4, 4, 4],
[5, 5, 5],
[6, 6, 6]],
[[7, 7, 7],
[8, 8, 8],
[9, 9, 9]]])