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2016-07-17 12:21:29 -05:00

338 lines
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Python

import numpy as np
from skimage.segmentation import random_walker
from skimage.transform import resize
from skimage._shared._warnings import expected_warnings
# older versions of scipy raise a warning with new NumPy because they use
# numpy.rank() instead of arr.ndim or numpy.linalg.matrix_rank.
SCIPY_EXPECTED = 'numpy.linalg.matrix_rank|\A\Z'
PYAMG_EXPECTED_WARNING = 'pyamg|\A\Z'
PYAMG_SCIPY_EXPECTED = SCIPY_EXPECTED + '|' + PYAMG_EXPECTED_WARNING
def make_2d_syntheticdata(lx, ly=None):
if ly is None:
ly = lx
np.random.seed(1234)
data = np.zeros((lx, ly)) + 0.1 * np.random.randn(lx, ly)
small_l = int(lx // 5)
data[lx // 2 - small_l:lx // 2 + small_l,
ly // 2 - small_l:ly // 2 + small_l] = 1
data[lx // 2 - small_l + 1:lx // 2 + small_l - 1,
ly // 2 - small_l + 1:ly // 2 + small_l - 1] = (
0.1 * np.random.randn(2 * small_l - 2, 2 * small_l - 2))
data[lx // 2 - small_l, ly // 2 - small_l // 8:ly // 2 + small_l // 8] = 0
seeds = np.zeros_like(data)
seeds[lx // 5, ly // 5] = 1
seeds[lx // 2 + small_l // 4, ly // 2 - small_l // 4] = 2
return data, seeds
def make_3d_syntheticdata(lx, ly=None, lz=None):
if ly is None:
ly = lx
if lz is None:
lz = lx
np.random.seed(1234)
data = np.zeros((lx, ly, lz)) + 0.1 * np.random.randn(lx, ly, lz)
small_l = int(lx // 5)
data[lx // 2 - small_l:lx // 2 + small_l,
ly // 2 - small_l:ly // 2 + small_l,
lz // 2 - small_l:lz // 2 + small_l] = 1
data[lx // 2 - small_l + 1:lx // 2 + small_l - 1,
ly // 2 - small_l + 1:ly // 2 + small_l - 1,
lz // 2 - small_l + 1:lz // 2 + small_l - 1] = 0
# make a hole
hole_size = np.max([1, small_l // 8])
data[lx // 2 - small_l,
ly // 2 - hole_size:ly // 2 + hole_size,
lz // 2 - hole_size:lz // 2 + hole_size] = 0
seeds = np.zeros_like(data)
seeds[lx // 5, ly // 5, lz // 5] = 1
seeds[lx // 2 + small_l // 4,
ly // 2 - small_l // 4,
lz // 2 - small_l // 4] = 2
return data, seeds
def test_2d_bf():
lx = 70
ly = 100
data, labels = make_2d_syntheticdata(lx, ly)
labels_bf = random_walker(data, labels, beta=90, mode='bf')
assert (labels_bf[25:45, 40:60] == 2).all()
assert data.shape == labels.shape
full_prob_bf = random_walker(data, labels, beta=90, mode='bf',
return_full_prob=True)
assert (full_prob_bf[1, 25:45, 40:60] >=
full_prob_bf[0, 25:45, 40:60]).all()
assert data.shape == labels.shape
# Now test with more than two labels
labels[55, 80] = 3
full_prob_bf = random_walker(data, labels, beta=90, mode='bf',
return_full_prob=True)
assert (full_prob_bf[1, 25:45, 40:60] >=
full_prob_bf[0, 25:45, 40:60]).all()
assert len(full_prob_bf) == 3
assert data.shape == labels.shape
def test_2d_cg():
lx = 70
ly = 100
data, labels = make_2d_syntheticdata(lx, ly)
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
labels_cg = random_walker(data, labels, beta=90, mode='cg')
assert (labels_cg[25:45, 40:60] == 2).all()
assert data.shape == labels.shape
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
full_prob = random_walker(data, labels, beta=90, mode='cg',
return_full_prob=True)
assert (full_prob[1, 25:45, 40:60] >=
full_prob[0, 25:45, 40:60]).all()
assert data.shape == labels.shape
return data, labels_cg
def test_2d_cg_mg():
lx = 70
ly = 100
data, labels = make_2d_syntheticdata(lx, ly)
expected = 'scipy.sparse.sparsetools|%s' % PYAMG_SCIPY_EXPECTED
with expected_warnings([expected]):
labels_cg_mg = random_walker(data, labels, beta=90, mode='cg_mg')
assert (labels_cg_mg[25:45, 40:60] == 2).all()
assert data.shape == labels.shape
with expected_warnings([expected]):
full_prob = random_walker(data, labels, beta=90, mode='cg_mg',
return_full_prob=True)
assert (full_prob[1, 25:45, 40:60] >=
full_prob[0, 25:45, 40:60]).all()
assert data.shape == labels.shape
return data, labels_cg_mg
def test_types():
lx = 70
ly = 100
data, labels = make_2d_syntheticdata(lx, ly)
data = 255 * (data - data.min()) // (data.max() - data.min())
data = data.astype(np.uint8)
with expected_warnings([PYAMG_SCIPY_EXPECTED]):
labels_cg_mg = random_walker(data, labels, beta=90, mode='cg_mg')
assert (labels_cg_mg[25:45, 40:60] == 2).all()
assert data.shape == labels.shape
return data, labels_cg_mg
def test_reorder_labels():
lx = 70
ly = 100
data, labels = make_2d_syntheticdata(lx, ly)
labels[labels == 2] = 4
labels_bf = random_walker(data, labels, beta=90, mode='bf')
assert (labels_bf[25:45, 40:60] == 2).all()
assert data.shape == labels.shape
return data, labels_bf
def test_2d_inactive():
lx = 70
ly = 100
data, labels = make_2d_syntheticdata(lx, ly)
labels[10:20, 10:20] = -1
labels[46:50, 33:38] = -2
labels = random_walker(data, labels, beta=90)
assert (labels.reshape((lx, ly))[25:45, 40:60] == 2).all()
assert data.shape == labels.shape
return data, labels
def test_3d():
n = 30
lx, ly, lz = n, n, n
data, labels = make_3d_syntheticdata(lx, ly, lz)
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
labels = random_walker(data, labels, mode='cg')
assert (labels.reshape(data.shape)[13:17, 13:17, 13:17] == 2).all()
assert data.shape == labels.shape
return data, labels
def test_3d_inactive():
n = 30
lx, ly, lz = n, n, n
data, labels = make_3d_syntheticdata(lx, ly, lz)
old_labels = np.copy(labels)
labels[5:25, 26:29, 26:29] = -1
after_labels = np.copy(labels)
with expected_warnings(['"cg" mode|CObject type' + '|' + SCIPY_EXPECTED]):
labels = random_walker(data, labels, mode='cg')
assert (labels.reshape(data.shape)[13:17, 13:17, 13:17] == 2).all()
assert data.shape == labels.shape
return data, labels, old_labels, after_labels
def test_multispectral_2d():
lx, ly = 70, 100
data, labels = make_2d_syntheticdata(lx, ly)
data = data[..., np.newaxis].repeat(2, axis=-1) # Expect identical output
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
multi_labels = random_walker(data, labels, mode='cg',
multichannel=True)
assert data[..., 0].shape == labels.shape
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
single_labels = random_walker(data[..., 0], labels, mode='cg')
assert (multi_labels.reshape(labels.shape)[25:45, 40:60] == 2).all()
assert data[..., 0].shape == labels.shape
return data, multi_labels, single_labels, labels
def test_multispectral_3d():
n = 30
lx, ly, lz = n, n, n
data, labels = make_3d_syntheticdata(lx, ly, lz)
data = data[..., np.newaxis].repeat(2, axis=-1) # Expect identical output
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
multi_labels = random_walker(data, labels, mode='cg',
multichannel=True)
assert data[..., 0].shape == labels.shape
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
single_labels = random_walker(data[..., 0], labels, mode='cg')
assert (multi_labels.reshape(labels.shape)[13:17, 13:17, 13:17] == 2).all()
assert (single_labels.reshape(labels.shape)[13:17, 13:17, 13:17] == 2).all()
assert data[..., 0].shape == labels.shape
return data, multi_labels, single_labels, labels
def test_spacing_0():
n = 30
lx, ly, lz = n, n, n
data, _ = make_3d_syntheticdata(lx, ly, lz)
# Rescale `data` along Z axis
data_aniso = np.zeros((n, n, n // 2))
for i, yz in enumerate(data):
data_aniso[i, :, :] = resize(yz, (n, n // 2))
# Generate new labels
small_l = int(lx // 5)
labels_aniso = np.zeros_like(data_aniso)
labels_aniso[lx // 5, ly // 5, lz // 5] = 1
labels_aniso[lx // 2 + small_l // 4,
ly // 2 - small_l // 4,
lz // 4 - small_l // 8] = 2
# Test with `spacing` kwarg
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
labels_aniso = random_walker(data_aniso, labels_aniso, mode='cg',
spacing=(1., 1., 0.5))
assert (labels_aniso[13:17, 13:17, 7:9] == 2).all()
def test_spacing_1():
n = 30
lx, ly, lz = n, n, n
data, _ = make_3d_syntheticdata(lx, ly, lz)
# Rescale `data` along Y axis
# `resize` is not yet 3D capable, so this must be done by looping in 2D.
data_aniso = np.zeros((n, n * 2, n))
for i, yz in enumerate(data):
data_aniso[i, :, :] = resize(yz, (n * 2, n))
# Generate new labels
small_l = int(lx // 5)
labels_aniso = np.zeros_like(data_aniso)
labels_aniso[lx // 5, ly // 5, lz // 5] = 1
labels_aniso[lx // 2 + small_l // 4,
ly - small_l // 2,
lz // 2 - small_l // 4] = 2
# Test with `spacing` kwarg
# First, anisotropic along Y
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
labels_aniso = random_walker(data_aniso, labels_aniso, mode='cg',
spacing=(1., 2., 1.))
assert (labels_aniso[13:17, 26:34, 13:17] == 2).all()
# Rescale `data` along X axis
# `resize` is not yet 3D capable, so this must be done by looping in 2D.
data_aniso = np.zeros((n, n * 2, n))
for i in range(data.shape[1]):
data_aniso[i, :, :] = resize(data[:, 1, :], (n * 2, n))
# Generate new labels
small_l = int(lx // 5)
labels_aniso2 = np.zeros_like(data_aniso)
labels_aniso2[lx // 5, ly // 5, lz // 5] = 1
labels_aniso2[lx - small_l // 2,
ly // 2 + small_l // 4,
lz // 2 - small_l // 4] = 2
# Anisotropic along X
with expected_warnings(['"cg" mode' + '|' + SCIPY_EXPECTED]):
labels_aniso2 = random_walker(data_aniso,
labels_aniso2,
mode='cg', spacing=(2., 1., 1.))
assert (labels_aniso2[26:34, 13:17, 13:17] == 2).all()
def test_trivial_cases():
# When all voxels are labeled
img = np.ones((10, 10))
labels = np.ones((10, 10))
with expected_warnings(["Returning provided labels"]):
pass_through = random_walker(img, labels)
np.testing.assert_array_equal(pass_through, labels)
# When all voxels are labeled AND return_full_prob is True
labels[:, :5] = 3
expected = np.concatenate(((labels == 1)[..., np.newaxis],
(labels == 3)[..., np.newaxis]), axis=2)
with expected_warnings(["Returning provided labels"]):
test = random_walker(img, labels, return_full_prob=True)
np.testing.assert_array_equal(test, expected)
def test_length2_spacing():
# If this passes without raising an exception (warnings OK), the new
# spacing code is working properly.
np.random.seed(42)
img = np.ones((10, 10)) + 0.2 * np.random.normal(size=(10, 10))
labels = np.zeros((10, 10), dtype=np.uint8)
labels[2, 4] = 1
labels[6, 8] = 4
random_walker(img, labels, spacing=(1., 2.))
def test_bad_inputs():
# Too few dimensions
img = np.ones(10)
labels = np.arange(10)
np.testing.assert_raises(ValueError, random_walker, img, labels)
np.testing.assert_raises(ValueError,
random_walker, img, labels, multichannel=True)
# Too many dimensions
np.random.seed(42)
img = np.random.normal(size=(3, 3, 3, 3, 3))
labels = np.arange(3 ** 5).reshape(img.shape)
np.testing.assert_raises(ValueError, random_walker, img, labels)
np.testing.assert_raises(ValueError,
random_walker, img, labels, multichannel=True)
# Spacing incorrect length
img = np.random.normal(size=(10, 10))
labels = np.zeros((10, 10))
labels[2, 4] = 2
labels[6, 8] = 5
np.testing.assert_raises(ValueError,
random_walker, img, labels, spacing=(1,))
if __name__ == '__main__':
np.testing.run_module_suite()