def parallel_projection2d(volume, geometry):
"""
Wrapper function for making the layer call.
Args:
volume: Input volume to project.
geometry: Corresponding GeometryParallel2D Object defining parameters.
Returns:
Initialized lme_custom_ops.parallel_projection2d layer.
"""
batch = tf.shape(volume)[0]
return pyronn_layers.parallel_projection2d(
volume,
projection_shape=geometry.sinogram_shape,
volume_origin=tf.cast(tf.broadcast_to(
geometry.volume_origin,
tf.concat([[batch], tf.shape(geometry.volume_origin)], axis=0)),
dtype=tf.float32),
detector_origin=tf.cast(tf.broadcast_to(
geometry.detector_origin,
tf.concat([[batch], tf.shape(geometry.detector_origin)], axis=0)),
dtype=tf.float32),
volume_spacing=tf.cast(tf.broadcast_to(
geometry.volume_spacing,
tf.concat([[batch], tf.shape(geometry.volume_spacing)], axis=0)),
dtype=tf.float32),
detector_spacing=tf.cast(tf.broadcast_to(
geometry.detector_spacing,
tf.concat([[batch], tf.shape(geometry.detector_spacing)], axis=0)),
dtype=tf.float32),
ray_vectors=tf.cast(tf.broadcast_to(
geometry.ray_vectors,
tf.concat([[batch], tf.shape(geometry.ray_vectors)], axis=0)),
dtype=tf.float32))
def parallel_projection2d(volume, geometry):
"""
Wrapper function for making the layer call.
Args:
volume: Input volume to project.
geometry: Corresponding GeometryParallel2D Object defining parameters.
Returns:
Initialized lme_custom_ops.parallel_projection2d layer.
"""
batch = np.shape(volume)[0]
return pyronn_layers.parallel_projection2d(volume,
projection_shape=geometry.sinogram_shape,
volume_origin=np.broadcast_to(geometry.volume_origin, [batch, *np.shape(geometry.volume_origin)]),
detector_origin=np.broadcast_to(geometry.detector_origin, [batch, *np.shape(geometry.detector_origin)]),
volume_spacing=np.broadcast_to(geometry.volume_spacing, [batch, *np.shape(geometry.volume_spacing)]),
detector_spacing=np.broadcast_to(geometry.detector_spacing, [batch, *np.shape(geometry.detector_spacing)]),
ray_vectors=np.broadcast_to(geometry.ray_vectors, [batch, *np.shape(geometry.ray_vectors)]))
def parallel_projection2d(volume, geometry):
"""
Wrapper function for making the layer call.
Args:
volume: Input volume to project.
geometry: Corresponding GeometryParallel2D Object defining parameters.
Returns:
Initialized lme_custom_ops.parallel_projection2d layer.
"""
return pyronn_layers.parallel_projection2d(volume,
volume_shape=geometry.volume_shape,
projection_shape=geometry.sinogram_shape,
volume_origin=geometry.tensor_proto_volume_origin,
detector_origin=geometry.tensor_proto_detector_origin,
volume_spacing=geometry.tensor_proto_volume_spacing,
detector_spacing=geometry.tensor_proto_detector_spacing,
ray_vectors=geometry.tensor_proto_ray_vectors)
def _backproject_grad(op, grad):
'''
Compute the gradient of the backprojector op by invoking the forward projector.
'''
proj = pyronn_layers.parallel_projection2d(
volume=grad,
projection_shape=op.inputs[0].shape[1:],
volume_origin=op.inputs[2],
detector_origin=op.inputs[3],
volume_spacing=op.inputs[4],
detector_spacing=op.inputs[5],
ray_vectors=op.inputs[6],
)
return [
proj,
tf.stop_gradient(op.inputs[1]),
tf.stop_gradient(op.inputs[2]),
tf.stop_gradient(op.inputs[3]),
tf.stop_gradient(op.inputs[4]),
tf.stop_gradient(op.inputs[5]),
tf.stop_gradient(op.inputs[6])
]