您可以使用scipy.ndimage.maximum_filter
:
In [28]: from scipy.ndimage import maximum_filter
下面是一個示例R
:
In [29]: R
Out[29]:
array([[3, 3, 0, 0, 3],
[0, 0, 2, 1, 3],
[0, 1, 1, 1, 2],
[3, 2, 1, 2, 0],
[2, 2, 1, 2, 1]])
得到最大的3×3的窗口:
In [30]: mx = maximum_filter(R, size=3)
In [31]: mx
Out[31]:
array([[3, 3, 3, 3, 3],
[3, 3, 3, 3, 3],
[3, 3, 2, 3, 3],
[3, 3, 2, 2, 2],
[3, 3, 2, 2, 2]])
比較mx
至R
;這是一個布爾矩陣:
In [32]: mx == R
Out[32]:
array([[ True, True, False, False, True],
[False, False, False, False, True],
[False, False, False, False, False],
[ True, False, False, True, False],
[False, False, False, True, False]], dtype=bool)
使用np.where
創建O
:
In [33]: O = np.where(mx == R, R, 0)
In [34]: O
Out[34]:
array([[3, 3, 0, 0, 3],
[0, 0, 0, 0, 3],
[0, 0, 0, 0, 0],
[3, 0, 0, 2, 0],
[0, 0, 0, 2, 0]])