def test_morphsnakes_incorrect_ndim():
img = cp.zeros((4, 4, 4, 4))
ls = cp.zeros((4, 4, 4, 4))
with pytest.raises(ValueError):
morphological_chan_vese(img, iterations=1, init_level_set=ls)
with pytest.raises(ValueError):
morphological_geodesic_active_contour(img,
iterations=1,
init_level_set=ls)
def test_morphsnakes_simple_shape_chan_vese():
img = gaussian_blob()
ls1 = disk_level_set(img.shape, center=(5, 5), radius=3)
ls2 = disk_level_set(img.shape, center=(5, 5), radius=6)
acwe_ls1 = morphological_chan_vese(img, iterations=10, init_level_set=ls1)
acwe_ls2 = morphological_chan_vese(img, iterations=10, init_level_set=ls2)
assert_array_equal(acwe_ls1, acwe_ls2)
assert acwe_ls1.dtype == acwe_ls2.dtype == cp.int8
def test_morphsnakes_black():
img = cp.zeros((11, 11))
ls = disk_level_set(img.shape, (5, 5), 3)
ref_zeros = cp.zeros(img.shape, dtype=cp.int8)
ref_ones = cp.ones(img.shape, dtype=cp.int8)
acwe_ls = morphological_chan_vese(img, iterations=6, init_level_set=ls)
assert_array_equal(acwe_ls, ref_zeros)
gac_ls = morphological_geodesic_active_contour(img,
iterations=6,
init_level_set=ls)
assert_array_equal(gac_ls, ref_zeros)
gac_ls2 = morphological_geodesic_active_contour(
img,
iterations=6,
init_level_set=ls,
balloon=1,
threshold=-1,
smoothing=0,
)
assert_array_equal(gac_ls2, ref_ones)
assert acwe_ls.dtype == gac_ls.dtype == gac_ls2.dtype == cp.int8
def test_init_level_sets():
image = cp.zeros((6, 6))
checkerboard_ls = morphological_chan_vese(image, 0, "checkerboard")
checkerboard_ref = cp.asarray(
[
[0, 0, 0, 0, 0, 1],
[0, 0, 0, 0, 0, 1],
[0, 0, 0, 0, 0, 1],
[0, 0, 0, 0, 0, 1],
[0, 0, 0, 0, 0, 1],
[1, 1, 1, 1, 1, 0],
],
dtype=cp.int8,
)
disk_ls = morphological_geodesic_active_contour(image, 0, "disk")
disk_ref = cp.asarray(
[
[0, 0, 0, 0, 0, 0],
[0, 0, 1, 1, 1, 0],
[0, 1, 1, 1, 1, 1],
[0, 1, 1, 1, 1, 1],
[0, 1, 1, 1, 1, 1],
[0, 0, 1, 1, 1, 0],
],
dtype=cp.int8,
)
assert_array_equal(checkerboard_ls, checkerboard_ref)
assert_array_equal(disk_ls, disk_ref)
def test_morphsnakes_3d():
image = cp.zeros((7, 7, 7))
evolution = []
def callback(x):
evolution.append(x.sum())
ls = morphological_chan_vese(image, 5, "disk", iter_callback=callback)
# Check that the initial disk level set is correct
assert evolution[0] == 81
# Check that the final level set is correct
assert ls.sum() == 0
# Check that the contour is shrinking at every iteration
for v1, v2 in zip(evolution[:-1], evolution[1:]):
assert v1 >= v2