Optimization comparison

Walkthrough

Import VAMToolbox and numpy. Create the target Create the TargetGeometry object and the ProjectionGeometry object.

import vamtoolbox as vam
import numpy as np

target_geo = vam.geometry.TargetGeometry(imagefilename=vam.resources.load("reschart.png"),pixels=501)

num_angles = 720
angles = np.linspace(0, 360 - 360 / num_angles, num_angles)
proj_geo = vam.geometry.ProjectionGeometry(angles,ray_type='parallel',CUDA=True)

Filtered back projection

# FBP
optimizer_params = vam.optimize.Options(method='FBP',filter='shepp-logan',verbose='plot')
opt_sino, opt_recon, error = vam.optimize.optimize(target_geo, proj_geo,optimizer_params)
opt_recon.show()

CAL

[Kelly et al., 2019]

# CAL
optimizer_params = vam.optimize.Options(method='CAL',filter='shepp-logan',n_iter=100,d_h=0.8,d_l=0.7,verbose='plot')
opt_sino, opt_recon, error = vam.optimize.optimize(target_geo, proj_geo,optimizer_params)
opt_recon.show()

Penalty minimization

[Bhattacharya et al., 2021]

# PM
optimizer_params = vam.optimize.Options(method='PM',filter='ram-lak',n_iter=100,d_h=0.8,d_l=0.7,verbose='plot')
opt_sino, opt_recon, error = vam.optimize.optimize(target_geo, proj_geo,optimizer_params)
opt_recon.show()

Object space model optimization

[Rackson et al., 2021]

# OSMO
optimizer_params = vam.optimize.Options(method='OSMO',filter='shepp-logan',n_iter=100,d_h=0.8,d_l=0.7,verbose='plot')
opt_sino, opt_recon, error = vam.optimize.optimize(target_geo, proj_geo,optimizer_params)
opt_recon.show()

Example file

examples/optimizationcomparison.py

import vamtoolbox as vam
import numpy as np

target_geo = vam.geometry.TargetGeometry(imagefilename=vam.resources.load("reschart.png"),pixels=501)

num_angles = 720
angles = np.linspace(0, 360 - 360 / num_angles, num_angles)
proj_geo = vam.geometry.ProjectionGeometry(angles,ray_type='parallel',CUDA=True)

# FBP
optimizer_params = vam.optimize.Options(method='FBP',filter='shepp-logan',verbose='plot')
opt_sino, opt_recon, error = vam.optimize.optimize(target_geo, proj_geo,optimizer_params)
opt_recon.show()

# CAL
optimizer_params = vam.optimize.Options(method='CAL',filter='shepp-logan',n_iter=100,d_h=0.8,d_l=0.7,verbose='plot')
opt_sino, opt_recon, error = vam.optimize.optimize(target_geo, proj_geo,optimizer_params)
opt_recon.show()

# PM
optimizer_params = vam.optimize.Options(method='PM',filter='ram-lak',n_iter=100,d_h=0.8,d_l=0.7,verbose='plot')
opt_sino, opt_recon, error = vam.optimize.optimize(target_geo, proj_geo,optimizer_params)
opt_recon.show()

# OSMO
optimizer_params = vam.optimize.Options(method='OSMO',filter='shepp-logan',n_iter=100,d_h=0.8,d_l=0.7,verbose='plot')
opt_sino, opt_recon, error = vam.optimize.optimize(target_geo, proj_geo,optimizer_params)
opt_recon.show()