def test_fbp_reconstruction_filters(filter_type, frequency_scaling):
"""Validate that the various filters work as expected."""
apart = odl.uniform_partition(0, np.pi, 500)
discr_reco_space = odl.uniform_discr([-20, -20], [20, 20], [100, 100],
dtype='float32')
# Geometry
dpart = odl.uniform_partition(-30, 30, 500)
geom = tomo.Parallel2dGeometry(apart, dpart)
# Ray transform
projector = tomo.RayTransform(discr_reco_space, geom, impl='astra_cuda')
# Create Shepp-Logan phantom
vol = odl.phantom.shepp_logan(projector.domain, modified=False)
# Project data
projections = projector(vol)
# Create FBP operator with filters and apply to projections
fbp_operator = odl.tomo.fbp_op(projector,
filter_type=filter_type,
frequency_scaling=frequency_scaling)
fbp_result = fbp_operator(projections)
maxerr = vol.norm() / 5.0
error = vol.dist(fbp_result)
assert error < maxerr
def geometry(request):
geom = request.param
m = 100
n_angles = 100
if geom == 'par2d':
apart = odl.uniform_partition(0, np.pi, n_angles)
dpart = odl.uniform_partition(-30, 30, m)
return tomo.Parallel2dGeometry(apart, dpart)
elif geom == 'par3d':
apart = odl.uniform_partition(0, np.pi, n_angles)
dpart = odl.uniform_partition([-30, -30], [30, 30], (m, m))
return tomo.Parallel3dAxisGeometry(apart, dpart)
elif geom == 'cone2d':
apart = odl.uniform_partition(0, 2 * np.pi, n_angles)
dpart = odl.uniform_partition(-30, 30, m)
return tomo.FanFlatGeometry(apart,
dpart,
src_radius=200,
det_radius=100)
elif geom == 'cone3d':
apart = odl.uniform_partition(0, 2 * np.pi, n_angles)
dpart = odl.uniform_partition([-60, -60], [60, 60], (m, m))
return tomo.CircularConeFlatGeometry(apart,
dpart,
src_radius=200,
det_radius=100)
elif geom == 'helical':
apart = odl.uniform_partition(0, 8 * 2 * np.pi, n_angles)
dpart = odl.uniform_partition([-30, -3], [30, 3], (m, m))
return tomo.HelicalConeFlatGeometry(apart,
dpart,
pitch=5.0,
src_radius=200,
det_radius=100)
else:
raise ValueError('geom not valid')
def projector(request, dtype):
n_angles = 200
geom, impl, angle = request.param.split()
if angle == 'uniform':
apart = odl.uniform_partition(0, 2 * np.pi, n_angles)
elif angle == 'random':
# Linearly spaced with random noise
min_pt = 2 * (2.0 * np.pi) / n_angles
max_pt = (2.0 * np.pi) - 2 * (2.0 * np.pi) / n_angles
points = np.linspace(min_pt, max_pt, n_angles)
points += np.random.rand(n_angles) * (max_pt - min_pt) / (5 * n_angles)
apart = odl.nonuniform_partition(points)
elif angle == 'nonuniform':
# Angles spaced quadratically
min_pt = 2 * (2.0 * np.pi) / n_angles
max_pt = (2.0 * np.pi) - 2 * (2.0 * np.pi) / n_angles
points = np.linspace(min_pt ** 0.5, max_pt ** 0.5, n_angles) ** 2
apart = odl.nonuniform_partition(points)
else:
raise ValueError('angle not valid')
if geom == 'par2d':
# Discrete reconstruction space
discr_reco_space = odl.uniform_discr([-20, -20], [20, 20],
[100, 100], dtype=dtype)
# Geometry
dpart = odl.uniform_partition(-30, 30, 200)
geom = tomo.Parallel2dGeometry(apart, dpart)
# Ray transform
return tomo.RayTransform(discr_reco_space, geom,
impl=impl)
elif geom == 'par3d':
# Discrete reconstruction space
discr_reco_space = odl.uniform_discr([-20, -20, -20], [20, 20, 20],
[100, 100, 100], dtype=dtype)
# Geometry
dpart = odl.uniform_partition([-30, -30], [30, 30], [200, 200])
geom = tomo.Parallel3dAxisGeometry(apart, dpart, axis=[1, 0, 0])
# Ray transform
return tomo.RayTransform(discr_reco_space, geom,
impl=impl)
elif geom == 'cone2d':
# Discrete reconstruction space
discr_reco_space = odl.uniform_discr([-20, -20], [20, 20],
[100, 100], dtype=dtype)
# Geometry
dpart = odl.uniform_partition(-30, 30, 200)
geom = tomo.FanFlatGeometry(apart, dpart,
src_radius=200, det_radius=100)
# Ray transform
return tomo.RayTransform(discr_reco_space, geom,
impl=impl)
elif geom == 'cone3d':
# Discrete reconstruction space
discr_reco_space = odl.uniform_discr([-20, -20, -20], [20, 20, 20],
[100, 100, 100], dtype=dtype)
# Geometry
dpart = odl.uniform_partition([-30, -30], [30, 30], [200, 200])
geom = tomo.CircularConeFlatGeometry(
apart, dpart, src_radius=200, det_radius=100, axis=[1, 0, 0])
# Ray transform
return tomo.RayTransform(discr_reco_space, geom,
impl=impl)
elif geom == 'helical':
# Discrete reconstruction space
discr_reco_space = odl.uniform_discr([-20, -20, 0], [20, 20, 40],
[100, 100, 100], dtype=dtype)
# Geometry
# TODO: angles
n_angle = 700
apart = odl.uniform_partition(0, 8 * 2 * np.pi, n_angle)
dpart = odl.uniform_partition([-30, -3], [30, 3], [200, 20])
geom = tomo.HelicalConeFlatGeometry(apart, dpart, pitch=5.0,
src_radius=200, det_radius=100)
# Ray transform
return tomo.RayTransform(discr_reco_space, geom,
impl=impl)
else:
raise ValueError('param not valid')
