FP3D_CUDA
This is a GPU implementation of a simple forward projection algorithm for 3D data sets. It takes a volume as input, and returns the projection data.
Supported geometries: parallel3d, parallel3d_vec, cone, cone_vec.
Configuration options
Name |
Description |
|---|---|
ProjectionDataId |
Data object ID to store the result. The computed forward projection is added to this data. |
VolumeDataId |
|
option.DetectorSuperSampling |
Each detector pixel will be subdivided by this factor along each dimension. This should only be used if detector pixels are larger than the voxels in the volume (default: 1). |
option.GPUindex |
The index of the GPU to use (default: 0). |
Example
import astra
import matplotlib.pyplot as plt
import numpy as np
# Create geometries
N = 256
N_ANGLES = 180
det_spacing = 1.0
angles = np.linspace(0, np.pi, N_ANGLES)
proj_geom = astra.create_proj_geom('parallel3d', det_spacing, det_spacing, N, N, angles)
vol_geom = astra.create_vol_geom(N, N, N)
# Generate phantom image
phantom_id, phantom = astra.data3d.shepp_logan(vol_geom)
# Calculate forward projection
projection_id = astra.data3d.create('-sino', proj_geom)
cfg = astra.astra_dict('FP3D_CUDA')
cfg['ProjectionDataId'] = projection_id
cfg['VolumeDataId'] = phantom_id
algorithm_id = astra.algorithm.create(cfg)
astra.algorithm.run(algorithm_id)
projection = astra.data3d.get(projection_id)
plt.imshow(projection[N//2], cmap='gray')
# Clean up
astra.data3d.delete([projection_id, phantom_id])
astra.algorithm.delete(algorithm_id)
%% Create phantom
N = 256;
phantom_ = repmat(phantom(N), [1, 1, N]);
%% Create geometries
det_spacing = 1.0;
N_ANGLES = 180;
angles = linspace(0, pi, N_ANGLES);
proj_geom = astra_create_proj_geom('parallel3d', det_spacing, det_spacing, N, N, angles);
vol_geom = astra_create_vol_geom(N, N, N);
%% Calculate forward projection
phantom_id = astra_mex_data3d('create', '-vol', vol_geom, phantom_);
projection_id = astra_mex_data3d('create', '-sino', proj_geom);
cfg = astra_struct('FP3D_CUDA');
cfg.ProjectionDataId = projection_id;
cfg.VolumeDataId = phantom_id;
algorithm_id = astra_mex_algorithm('create', cfg);
astra_mex_algorithm('run', algorithm_id);
projection = astra_mex_data3d('get', projection_id);
imshow(projection(:, :, N/2), []);
%% Clean up
astra_mex_data3d('delete', phantom_id, projection_id);
astra_mex_algorithm('delete', algorithm_id);