def test_lic_2D():
from scipy.ndimage.filters import line_integral_convolution as lic
# was used to generate results for test cases
# np.set_printoptions(
# formatter={'float':lambda x:'%.15e' % x},
# threshold=np.nan,
# linewidth=200)
image = np.zeros((4,5))
image[1,3] = 2
ones_ = np.ones_like(image)
velocity = ones_[:,:,None] * [[[0,2]]]
kernel = [1,0.5,0.1]
assert_allclose(lic(image, velocity, kernel, order=1, origin=-1,
weighted='integral'),
[[0, 0, 0, 0, 0],
[0, 0.2, 1, 2, 0],
[0, 0, 0, 0, 0],
[0, 0, 0, 0, 0]])
velocity = ones_[:,:,None] * [[[2,0]]]
assert_allclose(lic(image, velocity, kernel, order=1, origin=-1,
weighted='integral'),
[[0, 0, 0, 1, 0],
[0, 0, 0, 2, 0],
[0, 0, 0, 0, 0],
[0, 0, 0, 0, 0]])
velocity = (ones_[:,:,None] * [[[2,7]]])
assert_allclose(lic(image, velocity, kernel, order=1, origin=-1,
weighted='integral'),
[[0, 1.014323035580300e-01, 2.726070909971477e-01,
1.057018450115160e-02, 0],
[0, 8.317727549829940e-02, 7.043072775873462e-01,
2.027905867858025e+00, 0],
[0, 0, 0, 0, 0],
[0, 0, 0, 0, 0]])
assert_allclose(lic(image, velocity, kernel, order=3, origin=-1,
weighted='integral'),
[[-4.946647656636081e-03, 1.041909046074850e-01,
1.765005843082361e-01, 6.998764796487109e-04, 0],
[3.736874054193710e-04, 8.431107873364971e-02,
8.935011111472939e-01, 2.003570754474494e+00, 0],
[1.425762748747135e-04, -1.431941717202221e-02,
-1.164110107604186e-01, -4.650116996736128e-04, 0],
[0, 0, 0, 0, 0]])
def test_lic_1D():
from scipy.ndimage.filters import line_integral_convolution as lic
image = np.zeros((5,))
image[3] = 2
ones_ = np.ones_like(image)
velocity = 10 * ones_[:,None]
kernel = np.array([1, 0.5, 0.1])
assert_allclose(lic(image, velocity, kernel, order=1, origin=-1,
weighted='integral'), [0, 0.2, 1, 2, 0])
assert_allclose(lic(image, velocity, kernel, order=1, origin=None,
weighted='integral'), [0, 0.2, 1, 2, 0])
assert_allclose(lic(ones_, velocity, kernel, order=1, weighted='average'),
ones_)
assert_allclose(lic(image, velocity, kernel, order=1, weighted='integral'),
[0, 0, 0.2, 1, 2])
assert_allclose(lic(image.astype(bool), velocity, kernel, order=1,
weighted='integral'), [0, 0, 0.1, 0.5, 1])
assert_equal(lic(image.astype(bool), velocity, kernel, order=1,
weighted='integral').dtype.type,
np.float64)
assert_equal(lic(image.astype(bool), velocity.astype(np.float32),
kernel.astype(np.float32),
order=1, weighted='integral').dtype.type,
np.float32)
assert_equal(lic(image.astype(bool), velocity,
kernel.astype(np.float32),
order=1, weighted='integral').dtype.type,
np.float64)
assert_allclose(lic(image, velocity, kernel, order=1, origin=None,
weighted='integral', step_size='unit_time',
maximum_velocity=1.), [0, 0.2, 1, 2, 0])
assert_allclose(lic(image, velocity, kernel, order=1, origin=None,
weighted='integral', step_size='unit_time',
maximum_velocity=0.5), [0, 0, 0.35, 1.25, 0])