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from ccpi.framework import DataProcessor, ImageData
from ccpi.astra.utils import convert_geometry_to_astra
import astra
class AstraBackProjector3D(DataProcessor):
'''AstraBackProjector3D
Back project AcquisitionData to ImageData using ASTRA proj_geom, vol_geom.
Input: AcquisitionData
Parameter: proj_geom, vol_geom
Output: ImageData
'''
def __init__(self,
volume_geometry=None,
sinogram_geometry=None,
proj_geom=None,
vol_geom=None,
output_axes_order=None):
kwargs = {
'volume_geometry' : volume_geometry,
'sinogram_geometry' : sinogram_geometry,
'proj_geom' : proj_geom,
'vol_geom' : vol_geom,
'output_axes_order' : output_axes_order
}
#DataProcessor.__init__(self, **kwargs)
super(AstraBackProjector3D, self).__init__(**kwargs)
self.set_ImageGeometry(volume_geometry)
self.set_AcquisitionGeometry(sinogram_geometry)
# Set up ASTRA Volume and projection geometry, not to be stored in self
vol_geom, proj_geom = convert_geometry_to_astra(self.volume_geometry,
self.sinogram_geometry)
# Also store ASTRA geometries
self.vol_geom = vol_geom
self.proj_geom = proj_geom
def check_input(self, dataset):
if dataset.number_of_dimensions == 3:
return True
else:
raise ValueError("Expected input dimensions is 3, got {0}"\
.format(dataset.number_of_dimensions))
def set_ImageGeometry(self, volume_geometry):
self.volume_geometry = volume_geometry
def set_AcquisitionGeometry(self, sinogram_geometry):
self.sinogram_geometry = sinogram_geometry
def process(self, out=None):
DATA = self.get_input()
IM = ImageData(geometry=self.volume_geometry,
dimension_labels=self.output_axes_order)
rec_id, IM.array = astra.create_backprojection3d_gpu(DATA.as_array(),
self.proj_geom,
self.vol_geom)
astra.data3d.delete(rec_id)
# Scaling of 3D ASTRA backprojector, works both parallel and cone.
scaling = 1/self.volume_geometry.voxel_size_x**2
ret = scaling*IM
if out is None:
return ret
else:
out.fill(ret)
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