def test_sf_to_sh():
# Subdividing a hemi_icosahedron twice produces 81 unique points, which
# is more than enough to fit a order 8 (45 coefficients) spherical harmonic
sphere = hemi_icosahedron.subdivide(2)
mevals = np.array(([0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]))
mevecs = [np.array([[1, 0, 0], [0, 1, 0], [0, 0, 1]]),
np.array([[0, 1, 0], [1, 0, 0], [0, 0, 1]])]
odf = multi_tensor_odf(sphere.vertices, [0.5, 0.5], mevals, mevecs)
# 1D case with the 3 bases functions
odf_sh = sf_to_sh(odf, sphere, 8)
odf2 = sh_to_sf(odf_sh, sphere, 8)
assert_array_almost_equal(odf, odf2, 2)
odf_sh = sf_to_sh(odf, sphere, 8, "mrtrix")
odf2 = sh_to_sf(odf_sh, sphere, 8, "mrtrix")
assert_array_almost_equal(odf, odf2, 2)
odf_sh = sf_to_sh(odf, sphere, 8, "fibernav")
odf2 = sh_to_sf(odf_sh, sphere, 8, "fibernav")
assert_array_almost_equal(odf, odf2, 2)
# 2D case
odf2d = np.vstack((odf2, odf))
odf2d_sh = sf_to_sh(odf2d, sphere, 8)
odf2d_sf = sh_to_sf(odf2d_sh, sphere, 8)
assert_array_almost_equal(odf2d, odf2d_sf, 2)
def test_sf_to_sh():
# Subdividing a hemi_icosahedron twice produces 81 unique points, which
# is more than enough to fit a order 8 (45 coefficients) spherical harmonic
sphere = hemi_icosahedron.subdivide(2)
mevals = np.array(([0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]))
angles = [(0, 0), (90, 0)]
odf = multi_tensor_odf(sphere.vertices, mevals, angles, [50, 50])
# 1D case with the 3 bases functions
odf_sh = sf_to_sh(odf, sphere, 8)
odf2 = sh_to_sf(odf_sh, sphere, 8)
assert_array_almost_equal(odf, odf2, 2)
odf_sh = sf_to_sh(odf, sphere, 8, "mrtrix")
odf2 = sh_to_sf(odf_sh, sphere, 8, "mrtrix")
assert_array_almost_equal(odf, odf2, 2)
odf_sh = sf_to_sh(odf, sphere, 8, "fibernav")
odf2 = sh_to_sf(odf_sh, sphere, 8, "fibernav")
assert_array_almost_equal(odf, odf2, 2)
# 2D case
odf2d = np.vstack((odf2, odf))
odf2d_sh = sf_to_sh(odf2d, sphere, 8)
odf2d_sf = sh_to_sf(odf2d_sh, sphere, 8)
assert_array_almost_equal(odf2d, odf2d_sf, 2)
def test_r2_term_odf_sharp():
SNR = None
S0 = 1
angle = 75
_, fbvals, fbvecs = get_data('small_64D') #get_data('small_64D')
bvals = np.load(fbvals)
bvecs = np.load(fbvecs)
sphere = get_sphere('symmetric724')
gtab = gradient_table(bvals, bvecs)
mevals = np.array(([0.0015, 0.0003, 0.0003],
[0.0015, 0.0003, 0.0003]))
S, sticks = multi_tensor(gtab, mevals, S0, angles=[(0, 0), (angle, 0)],
fractions=[50, 50], snr=SNR)
mevecs = [all_tensor_evecs(sticks[0]).T,
all_tensor_evecs(sticks[1]).T]
odf_gt = multi_tensor_odf(sphere.vertices, [0.5, 0.5], mevals, mevecs)
odfs_sh = sf_to_sh(odf_gt, sphere, sh_order=8, basis_type=None)
fodf_sh = odf_sh_to_sharp(odfs_sh, sphere, basis=None, ratio=3 / 15.,
sh_order=8, lambda_=1., tau=0.1, r2_term=True)
fodf = sh_to_sf(fodf_sh, sphere, sh_order=8, basis_type=None)
directions_gt, _, _ = peak_directions(odf_gt, sphere)
directions, _, _ = peak_directions(fodf, sphere)
ang_sim = angular_similarity(directions_gt, directions)
assert_equal(ang_sim > 1.9, True)
assert_equal(directions.shape[0], 2)
def test_normalization():
""" Test the normalization routine applied after a convolution"""
# create kernel
D33 = 1.0
D44 = 0.04
t = 1
num_orientations = 5
k = EnhancementKernel(D33,
D44,
t,
orientations=num_orientations,
force_recompute=True)
# create a constant dataset
numorientations = k.get_orientations().shape[0]
spike = np.ones((7, 7, 7, numorientations), dtype=np.float64)
# convert dataset to SH
spike_sh = sf_to_sh(spike, k.get_sphere(), sh_order=8)
# convolve kernel with delta spike and apply normalization
csd_enh = convolve(spike_sh, k, sh_order=8, test_mode=True, normalize=True)
# convert dataset to DSF
csd_enh_dsf = sh_to_sf(csd_enh,
k.get_sphere(),
sh_order=8,
basis_type=None)
# test if the normalization is performed correctly
npt.assert_almost_equal(np.amax(csd_enh_dsf), np.amax(spike))
def test_odf_sh_to_sharp():
SNR = None
S0 = 1
_, fbvals, fbvecs = get_fnames('small_64D')
bvals, bvecs = read_bvals_bvecs(fbvals, fbvecs)
gtab = gradient_table(bvals, bvecs)
mevals = np.array(([0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]))
S, _ = multi_tensor(gtab,
mevals,
S0,
angles=[(10, 0), (100, 0)],
fractions=[50, 50],
snr=SNR)
sphere = default_sphere
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
qb = QballModel(gtab, sh_order=8, assume_normed=True)
qbfit = qb.fit(S)
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
odf_gt = qbfit.odf(sphere)
Z = np.linalg.norm(odf_gt)
odfs_gt = np.zeros((3, 1, 1, odf_gt.shape[0]))
odfs_gt[:, :, :] = odf_gt[:]
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
odfs_sh = sf_to_sh(odfs_gt, sphere, sh_order=8, basis_type=None)
odfs_sh /= Z
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
fodf_sh = odf_sh_to_sharp(odfs_sh,
sphere,
basis=None,
ratio=3 / 15.,
sh_order=8,
lambda_=1.,
tau=0.1)
fodf = sh_to_sf(fodf_sh, sphere, sh_order=8, basis_type=None)
directions2, _, _ = peak_directions(fodf[0, 0, 0], sphere)
assert_equal(directions2.shape[0], 2)
def create_odf_slicer(sh_fodf, mask, sphere, nb_subdivide, sh_order, sh_basis,
full_basis, orientation, scale, radial_scale, norm,
colormap):
"""
Create a ODF slicer actor displaying a fODF slice. The input volume is a
3-dimensional grid containing the SH coefficients of the fODF for each
voxel at each voxel, with the grid dimension having a size of 1 along the
axis corresponding to the selected orientation.
"""
# Subdivide the spheres if nb_subdivide is provided
if nb_subdivide is not None:
sphere = sphere.subdivide(nb_subdivide)
# Convert SH coefficients to SF coefficients
fodf = sh_to_sf(sh_fodf, sphere, sh_order, sh_basis, full_basis=full_basis)
# Get mask if supplied, otherwise create a mask discarding empty voxels
if mask is None:
mask = np.linalg.norm(fodf, axis=-1) > 0.
odf_actor = actor.odf_slicer(fodf,
mask=mask,
norm=norm,
radial_scale=radial_scale,
sphere=sphere,
colormap=colormap,
scale=scale)
set_display_extent(odf_actor, orientation, fodf.shape)
return odf_actor
def test_sf_to_sh():
# Subdividing a hemi_icosahedron twice produces 81 unique points, which
# is more than enough to fit a order 8 (45 coefficients) spherical harmonic
hemisphere = hemi_icosahedron.subdivide(2)
mevals = np.array([[0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]])
angles = [(0, 0), (60, 0)]
odf = multi_tensor_odf(hemisphere.vertices, mevals, angles, [50, 50])
# 1D case with the 2 symmetric bases functions
odf_sh = sf_to_sh(odf, hemisphere, 8, "tournier07")
odf_reconst = sh_to_sf(odf_sh, hemisphere, 8, "tournier07")
assert_array_almost_equal(odf, odf_reconst, 2)
odf_sh = sf_to_sh(odf, hemisphere, 8, "descoteaux07")
odf_reconst = sh_to_sf(odf_sh, hemisphere, 8, "descoteaux07")
assert_array_almost_equal(odf, odf_reconst, 2)
# We now create an asymmetric signal
# to try out our full SH basis
mevals = np.array([[0.0015, 0.0003, 0.0003]])
angles = [(0, 0)]
odf2 = multi_tensor_odf(hemisphere.vertices, mevals, angles, [100])
# We simulate our asymmetric signal by using a different ODF
# per hemisphere. The sphere used is a concatenation of the
# vertices of our hemisphere, for a total of 162 vertices.
sphere = Sphere(xyz=np.vstack((hemisphere.vertices, -hemisphere.vertices)))
asym_odf = np.append(odf, odf2)
# Try out full bases with order 10 (121 coefficients)
odf_sh = sf_to_sh(asym_odf, sphere, 10, "tournier07_full")
odf_reconst = sh_to_sf(odf_sh, sphere, 10, "tournier07_full")
assert_array_almost_equal(odf_reconst, asym_odf, 2)
odf_sh = sf_to_sh(asym_odf, sphere, 10, "descoteaux07_full")
odf_reconst = sh_to_sf(odf_sh, sphere, 10, "descoteaux07_full")
assert_array_almost_equal(odf_reconst, asym_odf, 2)
# An invalid basis name should raise an error
assert_raises(ValueError, sh_to_sf, odf, hemisphere, basis_type="")
assert_raises(ValueError, sf_to_sh, odf_sh, hemisphere, basis_type="")
# 2D case
odf2d = np.vstack((odf, odf))
odf2d_sh = sf_to_sh(odf2d, hemisphere, 8)
odf2d_sf = sh_to_sf(odf2d_sh, hemisphere, 8)
assert_array_almost_equal(odf2d, odf2d_sf, 2)
def test_mapmri_odf(radial_order=6):
gtab = get_gtab_taiwan_dsi()
# load repulsion 724 sphere
sphere = default_sphere
# load icosahedron sphere
l1, l2, l3 = [0.0015, 0.0003, 0.0003]
data, golden_directions = generate_signal_crossing(gtab,
l1,
l2,
l3,
angle2=90)
mapmod = MapmriModel(gtab,
radial_order=radial_order,
laplacian_regularization=True,
laplacian_weighting=0.01)
# repulsion724
sphere2 = create_unit_sphere(5)
mapfit = mapmod.fit(data)
odf = mapfit.odf(sphere)
directions, _, _ = peak_directions(odf, sphere, .35, 25)
assert_equal(len(directions), 2)
assert_almost_equal(angular_similarity(directions, golden_directions), 2,
1)
# 5 subdivisions
odf = mapfit.odf(sphere2)
directions, _, _ = peak_directions(odf, sphere2, .35, 25)
assert_equal(len(directions), 2)
assert_almost_equal(angular_similarity(directions, golden_directions), 2,
1)
sb_dummies = sticks_and_ball_dummies(gtab)
for sbd in sb_dummies:
data, golden_directions = sb_dummies[sbd]
asmfit = mapmod.fit(data)
odf = asmfit.odf(sphere2)
directions, _, _ = peak_directions(odf, sphere2, .35, 25)
if len(directions) <= 3:
assert_equal(len(directions), len(golden_directions))
if len(directions) > 3:
assert_equal(gfa(odf) < 0.1, True)
# for the isotropic implementation check if the odf spherical harmonics
# actually represent the discrete sphere function.
mapmod = MapmriModel(gtab,
radial_order=radial_order,
laplacian_regularization=True,
laplacian_weighting=0.01,
anisotropic_scaling=False)
mapfit = mapmod.fit(data)
odf = mapfit.odf(sphere)
odf_sh = mapfit.odf_sh()
odf_from_sh = sh_to_sf(odf_sh, sphere, radial_order, basis_type=None)
assert_almost_equal(odf, odf_from_sh, 10)
def test_convert_sh_to_full_basis():
hemisphere = hemi_icosahedron.subdivide(2)
mevals = np.array([[0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]])
angles = [(0, 0), (60, 0)]
odf = multi_tensor_odf(hemisphere.vertices, mevals, angles, [50, 50])
sh_coeffs = sf_to_sh(odf, hemisphere, 8)
full_sh_coeffs = convert_sh_to_full_basis(sh_coeffs)
odf_reconst = sh_to_sf(full_sh_coeffs, hemisphere, 8, full_basis=True)
assert_array_almost_equal(odf, odf_reconst, 2)
def test_r2_term_odf_sharp():
SNR = None
S0 = 1
angle = 45 # 45 degrees is a very tight angle to disentangle
_, fbvals, fbvecs = get_data('small_64D') # get_data('small_64D')
bvals = np.load(fbvals)
bvecs = np.load(fbvecs)
sphere = get_sphere('symmetric724')
gtab = gradient_table(bvals, bvecs)
mevals = np.array(([0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]))
angles = [(0, 0), (angle, 0)]
S, sticks = multi_tensor(gtab,
mevals,
S0,
angles=angles,
fractions=[50, 50],
snr=SNR)
odf_gt = multi_tensor_odf(sphere.vertices, mevals, angles, [50, 50])
odfs_sh = sf_to_sh(odf_gt, sphere, sh_order=8, basis_type=None)
fodf_sh = odf_sh_to_sharp(odfs_sh,
sphere,
basis=None,
ratio=3 / 15.,
sh_order=8,
lambda_=1.,
tau=0.1,
r2_term=True)
fodf = sh_to_sf(fodf_sh, sphere, sh_order=8, basis_type=None)
directions_gt, _, _ = peak_directions(odf_gt, sphere)
directions, _, _ = peak_directions(fodf, sphere)
ang_sim = angular_similarity(directions_gt, directions)
assert_equal(ang_sim > 1.9, True)
assert_equal(directions.shape[0], 2)
# This should pass as well
sdt_model = ConstrainedSDTModel(gtab, ratio=3 / 15., sh_order=8)
sdt_fit = sdt_model.fit(S)
fodf = sdt_fit.odf(sphere)
directions_gt, _, _ = peak_directions(odf_gt, sphere)
directions, _, _ = peak_directions(fodf, sphere)
ang_sim = angular_similarity(directions_gt, directions)
assert_equal(ang_sim > 1.9, True)
assert_equal(directions.shape[0], 2)
def test_shore_odf():
gtab = get_isbi2013_2shell_gtab()
# load repulsion 724 sphere
sphere = default_sphere
# load icosahedron sphere
sphere2 = create_unit_sphere(5)
data, golden_directions = sticks_and_ball(gtab,
d=0.0015,
S0=100,
angles=[(0, 0), (90, 0)],
fractions=[50, 50],
snr=None)
asm = ShoreModel(gtab,
radial_order=6,
zeta=700,
lambdaN=1e-8,
lambdaL=1e-8)
# repulsion724
asmfit = asm.fit(data)
odf = asmfit.odf(sphere)
odf_sh = asmfit.odf_sh()
odf_from_sh = sh_to_sf(odf_sh, sphere, 6, basis_type=None, legacy=True)
npt.assert_almost_equal(odf, odf_from_sh, 10)
expected_phi = shore_matrix(radial_order=6, zeta=700, gtab=gtab)
npt.assert_array_almost_equal(np.dot(expected_phi, asmfit.shore_coeff),
asmfit.fitted_signal())
directions, _, _ = peak_directions(odf, sphere, .35, 25)
npt.assert_equal(len(directions), 2)
npt.assert_almost_equal(angular_similarity(directions, golden_directions),
2, 1)
# 5 subdivisions
odf = asmfit.odf(sphere2)
directions, _, _ = peak_directions(odf, sphere2, .35, 25)
npt.assert_equal(len(directions), 2)
npt.assert_almost_equal(angular_similarity(directions, golden_directions),
2, 1)
sb_dummies = sticks_and_ball_dummies(gtab)
for sbd in sb_dummies:
data, golden_directions = sb_dummies[sbd]
asmfit = asm.fit(data)
odf = asmfit.odf(sphere2)
directions, _, _ = peak_directions(odf, sphere2, .35, 25)
if len(directions) <= 3:
npt.assert_equal(len(directions), len(golden_directions))
if len(directions) > 3:
npt.assert_equal(gfa(odf) < 0.1, True)
def test_mapmri_odf(radial_order=6):
gtab = get_gtab_taiwan_dsi()
# load symmetric 724 sphere
sphere = get_sphere('symmetric724')
# load icosahedron sphere
l1, l2, l3 = [0.0015, 0.0003, 0.0003]
data, golden_directions = generate_signal_crossing(gtab, l1, l2, l3,
angle2=90)
mapmod = MapmriModel(gtab, radial_order=radial_order,
laplacian_regularization=True,
laplacian_weighting=0.01)
# symmetric724
sphere2 = create_unit_sphere(5)
mapfit = mapmod.fit(data)
odf = mapfit.odf(sphere)
directions, _, _ = peak_directions(odf, sphere, .35, 25)
assert_equal(len(directions), 2)
assert_almost_equal(
angular_similarity(directions, golden_directions), 2, 1)
# 5 subdivisions
odf = mapfit.odf(sphere2)
directions, _, _ = peak_directions(odf, sphere2, .35, 25)
assert_equal(len(directions), 2)
assert_almost_equal(
angular_similarity(directions, golden_directions), 2, 1)
sb_dummies = sticks_and_ball_dummies(gtab)
for sbd in sb_dummies:
data, golden_directions = sb_dummies[sbd]
asmfit = mapmod.fit(data)
odf = asmfit.odf(sphere2)
directions, _, _ = peak_directions(odf, sphere2, .35, 25)
if len(directions) <= 3:
assert_equal(len(directions), len(golden_directions))
if len(directions) > 3:
assert_equal(gfa(odf) < 0.1, True)
# for the isotropic implementation check if the odf spherical harmonics
# actually represent the discrete sphere function.
mapmod = MapmriModel(gtab, radial_order=radial_order,
laplacian_regularization=True,
laplacian_weighting=0.01,
anisotropic_scaling=False)
mapfit = mapmod.fit(data)
odf = mapfit.odf(sphere)
odf_sh = mapfit.odf_sh()
odf_from_sh = sh_to_sf(odf_sh, sphere, radial_order, basis_type=None)
assert_almost_equal(odf, odf_from_sh, 10)
def test_odf_sh_to_sharp():
SNR = 100
S0 = 1
_, fbvals, fbvecs = get_data('small_64D')
bvals = np.load(fbvals)
bvecs = np.load(fbvecs)
gtab = gradient_table(bvals, bvecs)
mevals = np.array(([0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]))
S, sticks = multi_tensor(gtab,
mevals,
S0,
angles=[(10, 0), (100, 0)],
fractions=[50, 50],
snr=SNR)
sphere = get_sphere('symmetric724')
qb = QballModel(gtab, sh_order=8, assume_normed=True)
qbfit = qb.fit(S)
odf_gt = qbfit.odf(sphere)
Z = np.linalg.norm(odf_gt)
odfs_gt = np.zeros((3, 1, 1, odf_gt.shape[0]))
odfs_gt[:, :, :] = odf_gt[:]
odfs_sh = sf_to_sh(odfs_gt, sphere, sh_order=8, basis_type=None)
odfs_sh /= Z
fodf_sh = odf_sh_to_sharp(odfs_sh,
sphere,
basis=None,
ratio=3 / 15.,
sh_order=8,
lambda_=1.,
tau=1.)
fodf = sh_to_sf(fodf_sh, sphere, sh_order=8, basis_type=None)
directions2, _, _ = peak_directions(fodf[0, 0, 0], sphere)
assert_equal(directions2.shape[0], 2)
def main():
odf_file = sys.argv[1]
bvec_file = sys.argv[2]
basis = sys.argv[3]
odf = nib.load(odf_file)
odf_sh = odf.get_fdata()
bvec = np.loadtxt(bvec_file)
bvec = bvec[1:, :]
sph_gtab = Sphere(xyz=np.vstack(bvec))
print(odf_sh.shape)
odf_sf = sh_to_sf(odf_sh, sph_gtab, basis_type=basis, sh_order=8)
visu_odf(bvec, odf_sf)
def test_shore_odf():
gtab = get_isbi2013_2shell_gtab()
# load symmetric 724 sphere
sphere = get_sphere('symmetric724')
# load icosahedron sphere
sphere2 = create_unit_sphere(5)
data, golden_directions = SticksAndBall(gtab,
d=0.0015,
S0=100,
angles=[(0, 0), (90, 0)],
fractions=[50, 50],
snr=None)
asm = ShoreModel(gtab,
radial_order=6,
zeta=700,
lambdaN=1e-8,
lambdaL=1e-8)
# symmetric724
asmfit = asm.fit(data)
odf = asmfit.odf(sphere)
odf_sh = asmfit.odf_sh()
odf_from_sh = sh_to_sf(odf_sh, sphere, 6, basis_type=None)
assert_almost_equal(odf, odf_from_sh, 10)
directions, _, _ = peak_directions(odf, sphere, .35, 25)
assert_equal(len(directions), 2)
assert_almost_equal(angular_similarity(directions, golden_directions), 2,
1)
# 5 subdivisions
odf = asmfit.odf(sphere2)
directions, _, _ = peak_directions(odf, sphere2, .35, 25)
assert_equal(len(directions), 2)
assert_almost_equal(angular_similarity(directions, golden_directions), 2,
1)
sb_dummies = sticks_and_ball_dummies(gtab)
for sbd in sb_dummies:
data, golden_directions = sb_dummies[sbd]
asmfit = asm.fit(data)
odf = asmfit.odf(sphere2)
directions, _, _ = peak_directions(odf, sphere2, .35, 25)
if len(directions) <= 3:
assert_equal(len(directions), len(golden_directions))
if len(directions) > 3:
assert_equal(gfa(odf) < 0.1, True)
def test_shore_odf():
gtab = get_isbi2013_2shell_gtab()
# load symmetric 724 sphere
sphere = get_sphere('symmetric724')
# load icosahedron sphere
sphere2 = create_unit_sphere(5)
data, golden_directions = SticksAndBall(gtab, d=0.0015,
S0=100, angles=[(0, 0), (90, 0)],
fractions=[50, 50], snr=None)
asm = ShoreModel(gtab, radial_order=6,
zeta=700, lambdaN=1e-8, lambdaL=1e-8)
# symmetric724
asmfit = asm.fit(data)
odf = asmfit.odf(sphere)
odf_sh = asmfit.odf_sh()
odf_from_sh = sh_to_sf(odf_sh, sphere, 6, basis_type=None)
assert_almost_equal(odf, odf_from_sh, 10)
directions, _ , _ = peak_directions(odf, sphere, .35, 25)
assert_equal(len(directions), 2)
assert_almost_equal(
angular_similarity(directions, golden_directions), 2, 1)
# 5 subdivisions
odf = asmfit.odf(sphere2)
directions, _ , _ = peak_directions(odf, sphere2, .35, 25)
assert_equal(len(directions), 2)
assert_almost_equal(
angular_similarity(directions, golden_directions), 2, 1)
sb_dummies = sticks_and_ball_dummies(gtab)
for sbd in sb_dummies:
data, golden_directions = sb_dummies[sbd]
asmfit = asm.fit(data)
odf = asmfit.odf(sphere2)
directions, _ , _ = peak_directions(odf, sphere2, .35, 25)
if len(directions) <= 3:
assert_equal(len(directions), len(golden_directions))
if len(directions) > 3:
assert_equal(gfa(odf) < 0.1, True)
def test_r2_term_odf_sharp():
SNR = None
S0 = 1
angle = 45 #45 degrees is a very tight angle to disentangle
_, fbvals, fbvecs = get_data('small_64D') #get_data('small_64D')
bvals = np.load(fbvals)
bvecs = np.load(fbvecs)
sphere = get_sphere('symmetric724')
gtab = gradient_table(bvals, bvecs)
mevals = np.array(([0.0015, 0.0003, 0.0003],
[0.0015, 0.0003, 0.0003]))
angles = [(0, 0), (angle, 0)]
S, sticks = multi_tensor(gtab, mevals, S0, angles=angles,
fractions=[50, 50], snr=SNR)
odf_gt = multi_tensor_odf(sphere.vertices, mevals, angles, [50, 50])
odfs_sh = sf_to_sh(odf_gt, sphere, sh_order=8, basis_type=None)
fodf_sh = odf_sh_to_sharp(odfs_sh, sphere, basis=None, ratio=3 / 15.,
sh_order=8, lambda_=1., tau=0.1, r2_term=True)
fodf = sh_to_sf(fodf_sh, sphere, sh_order=8, basis_type=None)
directions_gt, _, _ = peak_directions(odf_gt, sphere)
directions, _, _ = peak_directions(fodf, sphere)
ang_sim = angular_similarity(directions_gt, directions)
assert_equal(ang_sim > 1.9, True)
assert_equal(directions.shape[0], 2)
# This should pass as well
sdt_model = ConstrainedSDTModel(gtab, ratio=3/15., sh_order=8)
sdt_fit = sdt_model.fit(S)
fodf = sdt_fit.odf(sphere)
directions_gt, _, _ = peak_directions(odf_gt, sphere)
directions, _, _ = peak_directions(fodf, sphere)
ang_sim = angular_similarity(directions_gt, directions)
assert_equal(ang_sim > 1.9, True)
assert_equal(directions.shape[0], 2)
def test_spherical_convolution_watson_sh(sh_order=4):
sphere = get_sphere('symmetric724')
n = sphere.vertices
bval = np.tile(1e9, len(n))
scheme = acquisition_scheme_from_bvalues(bval, n, delta, Delta)
indices_sphere_orientations = np.arange(sphere.vertices.shape[0])
np.random.shuffle(indices_sphere_orientations)
mu_index = indices_sphere_orientations[0]
mu_watson = sphere.vertices[mu_index]
mu_watson_sphere = utils.cart2sphere(mu_watson)[1:]
watson = distributions.SD1Watson(mu=mu_watson_sphere, odi=.3)
f_sf = watson(n=sphere.vertices)
f_sh = sf_to_sh(f_sf, sphere, sh_order)
lambda_par = 2e-9
stick = cylinder_models.C1Stick(mu=[0, 0], lambda_par=lambda_par)
k_sf = stick(scheme)
sh_matrix, m, n = real_sym_sh_mrtrix(sh_order, sphere.theta, sphere.phi)
sh_matrix_inv = np.linalg.pinv(sh_matrix)
k_sh = np.dot(sh_matrix_inv, k_sf)
k_rh = k_sh[m == 0]
fk_convolved_sh = sh_convolution(f_sh, k_rh)
fk_convolved_sf = sh_to_sf(fk_convolved_sh, sphere, sh_order)
# assert if spherical mean is the same between kernel and convolved kernel
assert_almost_equal(abs(np.mean(k_sf) - np.mean(fk_convolved_sf)), 0., 2)
# assert if the lowest signal attenuation (E(b,n)) is orientation along
# the orientation of the watson distribution.
min_position = np.argmin(fk_convolved_sf)
if min_position == mu_index:
assert_equal(min_position, mu_index)
else: # then it's the opposite direction
sphere_positions = np.arange(sphere.vertices.shape[0])
opposite_index = np.all(
np.round(sphere.vertices - mu_watson, 2) == 0, axis=1
)
min_position_opposite = sphere_positions[opposite_index]
assert_equal(min_position_opposite, mu_index)
def show_odf_sample(filename):
odf_sh = nib.load(filename).get_data()
from dipy.data import get_sphere
sphere = get_sphere('symmetric724')
odf = sh_to_sf(odf_sh, sphere, 8, 'mrtrix')
from dipy.viz import fvtk
r = fvtk.ren()
#odf = odf[:, :, 25]
#fvtk.add(r, fvtk.sphere_funcs(odf[:, :, None], sphere, norm=True))
odf = odf[:, 22, :]
#odf = odf[14: 23, 22, 34: 43]
#odf = odf[14:24, 22, 23:33]
fvtk.add(r, fvtk.sphere_funcs(odf[:, None, :], sphere, norm=True))
fvtk.show(r)
def test_odf_sh_to_sharp():
SNR = None
S0 = 1
_, fbvals, fbvecs = get_data('small_64D')
bvals = np.load(fbvals)
bvecs = np.load(fbvecs)
gtab = gradient_table(bvals, bvecs)
mevals = np.array(([0.0015, 0.0003, 0.0003],
[0.0015, 0.0003, 0.0003]))
S, sticks = multi_tensor(gtab, mevals, S0, angles=[(10, 0), (100, 0)],
fractions=[50, 50], snr=SNR)
sphere = get_sphere('symmetric724')
qb = QballModel(gtab, sh_order=8, assume_normed=True)
qbfit = qb.fit(S)
odf_gt = qbfit.odf(sphere)
Z = np.linalg.norm(odf_gt)
odfs_gt = np.zeros((3, 1, 1, odf_gt.shape[0]))
odfs_gt[:,:,:] = odf_gt[:]
odfs_sh = sf_to_sh(odfs_gt, sphere, sh_order=8, basis_type=None)
odfs_sh /= Z
fodf_sh = odf_sh_to_sharp(odfs_sh, sphere, basis=None, ratio=3 / 15.,
sh_order=8, lambda_=1., tau=0.1)
fodf = sh_to_sf(fodf_sh, sphere, sh_order=8, basis_type=None)
directions2, _, _ = peak_directions(fodf[0, 0, 0], sphere)
assert_equal(directions2.shape[0], 2)
def test_sf_to_sh():
# Subdividing a hemi_icosahedron twice produces 81 unique points, which
# is more than enough to fit a order 8 (45 coefficients) spherical harmonic
sphere = hemi_icosahedron.subdivide(2)
mevals = np.array(([0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]))
angles = [(0, 0), (90, 0)]
odf = multi_tensor_odf(sphere.vertices, mevals, angles, [50, 50])
# 1D case with the 3 bases functions
odf_sh = sf_to_sh(odf, sphere, 8)
odf2 = sh_to_sf(odf_sh, sphere, 8)
assert_array_almost_equal(odf, odf2, 2)
odf_sh = sf_to_sh(odf, sphere, 8, "tournier07")
odf2 = sh_to_sf(odf_sh, sphere, 8, "tournier07")
assert_array_almost_equal(odf, odf2, 2)
# Test the basis naming deprecation
with warnings.catch_warnings(record=True) as w:
warnings.simplefilter("always", DeprecationWarning)
odf_sh_mrtrix = sf_to_sh(odf, sphere, 8, "mrtrix")
odf2_mrtrix = sh_to_sf(odf_sh_mrtrix, sphere, 8, "mrtrix")
assert_array_almost_equal(odf, odf2_mrtrix, 2)
assert len(w) != 0
assert issubclass(w[-1].category, DeprecationWarning)
warnings.simplefilter("default", DeprecationWarning)
odf_sh = sf_to_sh(odf, sphere, 8, "descoteaux07")
odf2 = sh_to_sf(odf_sh, sphere, 8, "descoteaux07")
assert_array_almost_equal(odf, odf2, 2)
# Test the basis naming deprecation
with warnings.catch_warnings(record=True) as w:
warnings.simplefilter("always", DeprecationWarning)
odf_sh_fibernav = sf_to_sh(odf, sphere, 8, "fibernav")
odf2_fibernav = sh_to_sf(odf_sh_fibernav, sphere, 8, "fibernav")
assert_array_almost_equal(odf, odf2_fibernav, 2)
assert len(w) != 0
assert issubclass(w[-1].category, DeprecationWarning)
warnings.simplefilter("default", DeprecationWarning)
# 2D case
odf2d = np.vstack((odf2, odf))
odf2d_sh = sf_to_sh(odf2d, sphere, 8)
odf2d_sf = sh_to_sf(odf2d_sh, sphere, 8)
assert_array_almost_equal(odf2d, odf2d_sf, 2)
def test_sf_to_sh():
# Subdividing a hemi_icosahedron twice produces 81 unique points, which
# is more than enough to fit a order 8 (45 coefficients) spherical harmonic
sphere = hemi_icosahedron.subdivide(2)
mevals = np.array(([0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]))
angles = [(0, 0), (90, 0)]
odf = multi_tensor_odf(sphere.vertices, mevals, angles, [50, 50])
# 1D case with the 3 bases functions
odf_sh = sf_to_sh(odf, sphere, 8)
odf2 = sh_to_sf(odf_sh, sphere, 8)
assert_array_almost_equal(odf, odf2, 2)
odf_sh = sf_to_sh(odf, sphere, 8, "tournier07")
odf2 = sh_to_sf(odf_sh, sphere, 8, "tournier07")
assert_array_almost_equal(odf, odf2, 2)
# Test the basis naming deprecation
with warnings.catch_warnings(record=True) as w:
warnings.simplefilter("always", DeprecationWarning)
odf_sh_mrtrix = sf_to_sh(odf, sphere, 8, "mrtrix")
odf2_mrtrix = sh_to_sf(odf_sh_mrtrix, sphere, 8, "mrtrix")
assert_array_almost_equal(odf, odf2_mrtrix, 2)
assert len(w) != 0
assert issubclass(w[-1].category, DeprecationWarning)
warnings.simplefilter("default", DeprecationWarning)
odf_sh = sf_to_sh(odf, sphere, 8, "descoteaux07")
odf2 = sh_to_sf(odf_sh, sphere, 8, "descoteaux07")
assert_array_almost_equal(odf, odf2, 2)
# Test the basis naming deprecation
with warnings.catch_warnings(record=True) as w:
warnings.simplefilter("always", DeprecationWarning)
odf_sh_fibernav = sf_to_sh(odf, sphere, 8, "fibernav")
odf2_fibernav = sh_to_sf(odf_sh_fibernav, sphere, 8, "fibernav")
assert_array_almost_equal(odf, odf2_fibernav, 2)
assert len(w) != 0
assert issubclass(w[-1].category, DeprecationWarning)
warnings.simplefilter("default", DeprecationWarning)
# 2D case
odf2d = np.vstack((odf2, odf))
odf2d_sh = sf_to_sh(odf2d, sphere, 8)
odf2d_sf = sh_to_sf(odf2d_sh, sphere, 8)
assert_array_almost_equal(odf2d, odf2d_sf, 2)
def test_convert_sh_to_full_basis():
hemisphere = hemi_icosahedron.subdivide(2)
mevals = np.array([[0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]])
angles = [(0, 0), (60, 0)]
odf = multi_tensor_odf(hemisphere.vertices, mevals, angles, [50, 50])
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
sh_coeffs = sf_to_sh(odf, hemisphere, 8)
full_sh_coeffs = convert_sh_to_full_basis(sh_coeffs)
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
odf_reconst = sh_to_sf(full_sh_coeffs, hemisphere, 8, full_basis=True)
assert_array_almost_equal(odf, odf_reconst, 2)
def test_normalization():
""" Test the normalization routine applied after a convolution"""
# create kernel
D33 = 1.0
D44 = 0.04
t = 1
num_orientations = 5
k = EnhancementKernel(D33, D44, t, orientations=num_orientations, force_recompute=True)
# create a constant dataset
numorientations = k.get_orientations().shape[0]
spike = np.ones((7, 7, 7, numorientations), dtype=np.float64)
# convert dataset to SH
spike_sh = sf_to_sh(spike, k.get_sphere(), sh_order=8)
# convolve kernel with delta spike and apply normalization
csd_enh = convolve(spike_sh, k, sh_order=8, test_mode=True, normalize=True)
# convert dataset to DSF
csd_enh_dsf = sh_to_sf(csd_enh, k.get_sphere(), sh_order=8, basis_type=None)
# test if the normalization is performed correctly
npt.assert_almost_equal(np.amax(csd_enh_dsf), np.amax(spike))
#mask = data[..., 0] > 50
order = 4
csamodel = CsaOdfModel(gtab, order, smooth=0.006)
print 'Computing the CSA odf...'
csafit = csamodel.fit(data)
coeff = csafit._shm_coef
# dipy-dev compatible
#GFA = csafit.gfa
#nib.save(nib.Nifti1Image(GFA.astype('float32'), affine), 'gfa_csa.nii.gz')
nib.save(nib.Nifti1Image(coeff.astype('float32'), affine), 'csa_odf_sh.nii.gz')
sphere = get_sphere('symmetric724')
odfs = sh_to_sf(coeff[20:50,55:85, 38:39], sphere, order)
if vizu :
from dipy.viz import fvtk
r = fvtk.ren()
fvtk.add(r, fvtk.sphere_funcs(odfs, sphere, colormap='jet'))
fvtk.show(r)
fvtk.clear(r)
qballmodel = QballModel(gtab, order, smooth=0.006)
print 'Computing the QBALL odf...'
qballfit = qballmodel.fit(data)
coeff = qballfit._shm_coef
#GFA = qballfit.gfa
# dipy 0.6 compatible
Visualize the kernel
"""
from dipy.viz import fvtk
from dipy.data import get_sphere
from dipy.reconst.shm import sf_to_sh, sh_to_sf
ren = fvtk.ren()
# convolve kernel with delta spike
spike = np.zeros((7, 7, 7, k.get_orientations().shape[0]), dtype=np.float64)
spike[3, 3, 3, 0] = 1
spike_shm_conv = convolve(sf_to_sh(spike, k.get_sphere(), sh_order=8), k,
sh_order=8, test_mode=True)
sphere = get_sphere('symmetric724')
spike_sf_conv = sh_to_sf(spike_shm_conv, sphere, sh_order=8)
model_kernel = fvtk.sphere_funcs((spike_sf_conv * 6)[3,:,:,:],
sphere,
norm=False,
radial_scale=True)
fvtk.add(ren, model_kernel)
fvtk.camera(ren, pos=(30, 0, 0), focal=(0, 0, 0), viewup=(0, 0, 1), verbose=False)
fvtk.record(ren, out_path='kernel.png', size=(900, 900))
"""
.. figure:: kernel.png
:align: center
Visualization of the contour enhancement kernel.
"""
Visualize the kernel
"""
from dipy.viz import window, actor
from dipy.reconst.shm import sf_to_sh, sh_to_sf
scene = window.Scene()
# convolve kernel with delta spike
spike = np.zeros((7, 7, 7, k.get_orientations().shape[0]), dtype=np.float64)
spike[3, 3, 3, 0] = 1
spike_shm_conv = convolve(sf_to_sh(spike, k.get_sphere(), sh_order=8),
k,
sh_order=8,
test_mode=True)
spike_sf_conv = sh_to_sf(spike_shm_conv, default_sphere, sh_order=8)
model_kernel = actor.odf_slicer(spike_sf_conv * 6,
sphere=default_sphere,
norm=False,
scale=0.4)
model_kernel.display(x=3)
scene.add(model_kernel)
scene.set_camera(position=(30, 0, 0), focal_point=(0, 0, 0), view_up=(0, 0, 1))
window.record(scene, out_path='kernel.png', size=(900, 900))
if interactive:
window.show(scene)
"""
.. figure:: kernel.png
:align: center
Visualization of the contour enhancement kernel.
# Change this value to try other maximum orders
sh_order = 8
sh_coeffs = sf_to_sh(odf, sph, sh_order, sh_basis)
"""
``sh_coeffs`` is an array containing the SH coefficients multiplying the SH
functions of the chosen basis. We can use it as input of ``sh_to_sf`` to
reconstruct our original signal. We will now reproject our signal on a high
resolution sphere using ``sh_to_sf``.
"""
from dipy.data import get_sphere
from dipy.reconst.shm import sh_to_sf
high_res_sph = get_sphere('symmetric724').subdivide(2)
reconst = sh_to_sf(sh_coeffs, high_res_sph, sh_order, sh_basis)
scene.clear()
odf_actor = actor.odf_slicer(reconst[None, None, None, :], sphere=high_res_sph)
odf_actor.RotateX(90)
scene.add(odf_actor)
print('Saving output as symm_reconst.png')
window.record(scene, out_path='symm_reconst.png', size=(300, 300))
if interactive:
window.show(scene)
"""
.. figure:: symm_reconst.png
:align: center
Reconstruction of a symmetric signal on a high resolution sphere using a
def main():
logging.basicConfig(level=logging.INFO)
parser = _build_arg_parser()
args = parser.parse_args()
required = [args.bundle_filename, args.fod_filename, args.mask_filename]
assert_inputs_exist(parser, required)
out_efod = os.path.join(args.output_dir,
'{0}efod.nii.gz'.format(args.output_prefix))
out_priors = os.path.join(args.output_dir,
'{0}priors.nii.gz'.format(args.output_prefix))
out_todi_mask = os.path.join(
args.output_dir, '{0}todi_mask.nii.gz'.format(args.output_prefix))
out_endpoints_mask = os.path.join(
args.output_dir, '{0}endpoints_mask.nii.gz'.format(args.output_prefix))
required = [out_efod, out_priors, out_todi_mask, out_endpoints_mask]
assert_outputs_exist(parser, args, required)
if args.output_dir and not os.path.isdir(args.output_dir):
os.mkdir(args.output_dir)
img_sh = nib.load(args.fod_filename)
sh_shape = img_sh.shape
sh_order = find_order_from_nb_coeff(sh_shape)
img_mask = nib.load(args.mask_filename)
sft = load_tractogram(args.bundle_filename,
args.fod_filename,
trk_header_check=True)
sft.to_vox()
streamlines = sft.streamlines
if len(streamlines) < 1:
raise ValueError('The input bundle contains no streamline.')
# Compute TODI from streamlines
with TrackOrientationDensityImaging(img_mask.shape,
'repulsion724') as todi_obj:
todi_obj.compute_todi(streamlines, length_weights=True)
todi_obj.smooth_todi_dir()
todi_obj.smooth_todi_spatial(sigma=args.todi_sigma)
# Fancy masking of 1d indices to limit spatial dilation to WM
sub_mask_3d = np.logical_and(
img_mask.get_data(), todi_obj.reshape_to_3d(todi_obj.get_mask()))
sub_mask_1d = sub_mask_3d.flatten()[todi_obj.get_mask()]
todi_sf = todi_obj.get_todi()[sub_mask_1d]**2
# The priors should always be between 0 and 1
# A minimum threshold is set to prevent misaligned FOD from disappearing
todi_sf /= np.max(todi_sf, axis=-1, keepdims=True)
todi_sf[todi_sf < args.sf_threshold] = args.sf_threshold
# Memory friendly saving, as soon as possible saving then delete
priors_3d = np.zeros(sh_shape)
sphere = get_sphere('repulsion724')
priors_3d[sub_mask_3d] = sf_to_sh(todi_sf,
sphere,
sh_order=sh_order,
basis_type=args.sh_basis)
nib.save(nib.Nifti1Image(priors_3d, img_mask.affine), out_priors)
del priors_3d
input_sh_3d = img_sh.get_data().astype(np.float)
input_sf_1d = sh_to_sf(input_sh_3d[sub_mask_3d],
sphere,
sh_order=sh_order,
basis_type=args.sh_basis)
# Creation of the enhanced-FOD (direction-wise multiplication)
mult_sf_1d = input_sf_1d * todi_sf
del todi_sf
input_max_value = np.max(input_sf_1d, axis=-1, keepdims=True)
mult_max_value = np.max(mult_sf_1d, axis=-1, keepdims=True)
mult_positive_mask = np.squeeze(mult_max_value) > 0.0
mult_sf_1d[mult_positive_mask] = mult_sf_1d[mult_positive_mask] * \
input_max_value[mult_positive_mask] / \
mult_max_value[mult_positive_mask]
# Memory friendly saving
input_sh_3d[sub_mask_3d] = sf_to_sh(mult_sf_1d,
sphere,
sh_order=sh_order,
basis_type=args.sh_basis)
nib.save(nib.Nifti1Image(input_sh_3d, img_mask.affine), out_efod)
del input_sh_3d
nib.save(nib.Nifti1Image(sub_mask_3d.astype(np.int16), img_mask.affine),
out_todi_mask)
endpoints_mask = np.zeros(img_mask.shape, dtype=np.int16)
for streamline in streamlines:
if img_mask.get_data()[tuple(streamline[0].astype(np.int16))]:
endpoints_mask[tuple(streamline[0].astype(np.int16))] = 1
endpoints_mask[tuple(streamline[-1].astype(np.int16))] = 1
nib.save(nib.Nifti1Image(endpoints_mask, img_mask.affine),
out_endpoints_mask)
def test_r2_term_odf_sharp():
SNR = None
S0 = 1
angle = 45 # 45 degrees is a very tight angle to disentangle
_, fbvals, fbvecs = get_fnames('small_64D') # get_fnames('small_64D')
bvals, bvecs = read_bvals_bvecs(fbvals, fbvecs)
sphere = default_sphere
gtab = gradient_table(bvals, bvecs)
mevals = np.array(([0.0015, 0.0003, 0.0003], [0.0015, 0.0003, 0.0003]))
angles = [(0, 0), (angle, 0)]
S, _ = multi_tensor(gtab,
mevals,
S0,
angles=angles,
fractions=[50, 50],
snr=SNR)
odf_gt = multi_tensor_odf(sphere.vertices, mevals, angles, [50, 50])
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
odfs_sh = sf_to_sh(odf_gt, sphere, sh_order=8, basis_type=None)
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
fodf_sh = odf_sh_to_sharp(odfs_sh,
sphere,
basis=None,
ratio=3 / 15.,
sh_order=8,
lambda_=1.,
tau=0.1,
r2_term=True)
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
fodf = sh_to_sf(fodf_sh, sphere, sh_order=8, basis_type=None)
directions_gt, _, _ = peak_directions(odf_gt, sphere)
directions, _, _ = peak_directions(fodf, sphere)
ang_sim = angular_similarity(directions_gt, directions)
assert_equal(ang_sim > 1.9, True)
assert_equal(directions.shape[0], 2)
# This should pass as well
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
sdt_model = ConstrainedSDTModel(gtab, ratio=3 / 15., sh_order=8)
sdt_fit = sdt_model.fit(S)
with warnings.catch_warnings():
warnings.filterwarnings("ignore",
message=descoteaux07_legacy_msg,
category=PendingDeprecationWarning)
fodf = sdt_fit.odf(sphere)
directions_gt, _, _ = peak_directions(odf_gt, sphere)
directions, _, _ = peak_directions(fodf, sphere)
ang_sim = angular_similarity(directions_gt, directions)
assert_equal(ang_sim > 1.9, True)
assert_equal(directions.shape[0], 2)