I'm looking for a way to extract zones of ones in a binary numpy array to put different values, for instance, for the following array:
x=[[0,1,1,0,0,0],
[0,1,1,0,0,0],
[0,1,0,0,0,0],
[0,0,0,1,1,0],
[0,0,1,1,1,0],
[0,0,0,0,0,0]]
Expected result:
x=[[0,2,2,0,0,0],
[0,2,2,0,0,0],
[0,2,0,0,0,0],
[0,0,0,3,3,0],
[0,0,3,3,3,0],
[0,0,0,0,0,0]]
CodePudding user response:
Use scipy.ndimage.label
:
x=[[0,1,1,0,0,0],
[0,1,1,0,0,0],
[0,1,0,0,0,0],
[0,0,0,1,1,0],
[0,0,1,1,1,0],
[0,0,0,0,0,0]]
a = np.array(x)
from scipy.ndimage import label
b = label(a)[0]
output:
# b
array([[0, 1, 1, 0, 0, 0],
[0, 1, 1, 0, 0, 0],
[0, 1, 0, 0, 0, 0],
[0, 0, 0, 2, 2, 0],
[0, 0, 2, 2, 2, 0],
[0, 0, 0, 0, 0, 0]], dtype=int32)
to start labeling from 2:
b = (label(a)[0] 1)*a
output:
array([[0, 2, 2, 0, 0, 0],
[0, 2, 2, 0, 0, 0],
[0, 2, 0, 0, 0, 0],
[0, 0, 0, 3, 3, 0],
[0, 0, 3, 3, 3, 0],
[0, 0, 0, 0, 0, 0]])