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scikit-image/skimage/morphology/tests/test_skeletonize_3d.py
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Evgeni Burovski ba328e7531 MAINT: address review comments
Use recommended idioms in the .py wrapper
2016-02-20 17:29:13 +00:00

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6.4 KiB
Python

from __future__ import division, print_function, absolute_import
import os
import warnings
import numpy as np
from numpy.testing import (assert_equal, run_module_suite, assert_raises,
assert_)
import scipy.ndimage as ndi
import skimage
from skimage import io, draw, data_dir
from skimage.data import binary_blobs
from skimage.util import img_as_ubyte
from skimage.morphology import skeletonize_3d
# basic behavior tests (mostly copied over from 2D skeletonize)
def test_skeletonize_wrong_dim():
im = np.zeros(5, dtype=np.uint8)
assert_raises(ValueError, skeletonize_3d, im)
im = np.zeros((5, 5, 5, 5), dtype=np.uint8)
assert_raises(ValueError, skeletonize_3d, im)
def test_skeletonize_1D():
# a corner case of an image of a shape(1, N)
im = np.ones((5, 1), dtype=np.uint8)
res = skeletonize_3d(im)
assert_equal(res, im)
def test_skeletonize_no_foreground():
im = np.zeros((5, 5), dtype=np.uint8)
result = skeletonize_3d(im)
assert_equal(result, im)
def test_skeletonize_all_foreground():
im = np.ones((3, 4), dtype=np.uint8)
assert_equal(skeletonize_3d(im),
np.array([[0, 0, 0, 0],
[1, 1, 1, 1],
[0, 0, 0, 0]], dtype=np.uint8))
def test_skeletonize_single_point():
im = np.zeros((5, 5), dtype=np.uint8)
im[3, 3] = 1
result = skeletonize_3d(im)
assert_equal(result, im)
def test_skeletonize_already_thinned():
im = np.zeros((5, 5), dtype=np.uint8)
im[3, 1:-1] = 1
im[2, -1] = 1
im[4, 0] = 1
result = skeletonize_3d(im)
assert_equal(result, im)
def test_dtype_conv():
# check that the operation does the right thing with floats etc
# also check non-contiguous input
img = np.random.random((16, 16))[::2, ::2]
img[img < 0.5] = 0
orig = img.copy()
with warnings.catch_warnings():
# UserWarning for possible precision loss, expected
warnings.simplefilter('ignore', UserWarning)
res = skeletonize_3d(img)
assert_equal(res.dtype, np.uint8)
assert_equal(img, orig) # operation does not clobber the original
assert_equal(res.max(),
img_as_ubyte(img).max()) # the intensity range is preserved
def test_input():
# check that the input is not clobbered
# for 2D and 3D images of varying dtypes
imgs = [np.ones((8, 8), dtype=float), np.ones((4, 8, 8), dtype=float),
np.ones((8, 8), dtype=np.uint8), np.ones((4, 8, 8), dtype=np.uint8),
np.ones((8, 8), dtype=bool), np.ones((4, 8, 8), dtype=bool)]
for img in imgs:
yield check_input, img
def check_input(img):
orig = img.copy()
with warnings.catch_warnings():
# UserWarning for possible precision loss, expected
warnings.simplefilter('ignore', UserWarning)
res = skeletonize_3d(img)
assert_equal(img, orig)
def test_skeletonize_num_neighbours():
# an empty image
image = np.zeros((300, 300))
# foreground object 1
image[10:-10, 10:100] = 1
image[-100:-10, 10:-10] = 1
image[10:-10, -100:-10] = 1
# foreground object 2
rs, cs = draw.line(250, 150, 10, 280)
for i in range(10):
image[rs + i, cs] = 1
rs, cs = draw.line(10, 150, 250, 280)
for i in range(20):
image[rs + i, cs] = 1
# foreground object 3
ir, ic = np.indices(image.shape)
circle1 = (ic - 135)**2 + (ir - 150)**2 < 30**2
circle2 = (ic - 135)**2 + (ir - 150)**2 < 20**2
image[circle1] = 1
image[circle2] = 0
result = skeletonize_3d(image)
# there should never be a 2x2 block of foreground pixels in a skeleton
mask = np.array([[1, 1],
[1, 1]], np.uint8)
blocks = ndi.correlate(result, mask, mode='constant')
assert_(not np.any(blocks == 4))
def test_two_hole_image():
# test a simple 2D image against FIJI
img_o = np.array([[0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0],
[0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
[0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0],
[0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0],
[0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0],
[0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0],
[0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0],
[0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
[0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
[0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
[0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]],
dtype=np.uint8)
img_f = np.array([[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0],
[0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0],
[0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0],
[0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0],
[0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0],
[0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0],
[0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0],
[0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]],
dtype=np.uint8)
res = skeletonize_3d(img_o)
assert_equal(res, img_f)
def test_3d_vs_fiji():
# generate an image with blobs and compate its skeleton to
# the skeleton generated by FIJI
img = binary_blobs(32, 0.05, n_dim=3, seed=1234)
img = img[:-2, ...]
img = img.astype(np.uint8)*255
img_s = skeletonize_3d(img)
img_f = io.imread(os.path.join(data_dir, "_blobs_3d_fiji_skeleton.tif"))
assert_equal(img_s, img_f)
if __name__ == '__main__':
run_module_suite()