###########################################################################
# (C) 2016 Elettra - Sincrotrone Trieste S.C.p.A.. All rights reserved. #
# #
# #
# This file is part of STP-Core, the Python core of SYRMEP Tomo Project, #
# a software tool for the reconstruction of experimental CT datasets. #
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# STP-Core is free software: you can redistribute it and/or modify it #
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# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License #
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# You should have received a copy of the GNU General Public License #
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#
# Author: Francesco Brun
# Last modified: July, 8th 2016
#
from numpy import float32, linspace
import astra
import tvtomo
[docs]def recon_fista_tv(im, angles, lam, fista_iter, iter):
"""Reconstruct the input sinogram by using the FISTA-TV algorithm
Parameters
----------
im : array_like
Image data (sinogram) as numpy array.
angles : double
Value in radians representing the number of angles of the input sinogram.
lam : double
Regularization parameter of the FISTA algorithm.
fista_iter : int
Number of iterations of the FISTA algorihtm.
iter : int
Number of iterations of the TV minimization.
"""
# Create ASTRA geometries:
vol_geom = astra.create_vol_geom(im.shape[1] , im.shape[1])
proj_geom = astra.create_proj_geom('parallel', 1.0, im.shape[1], linspace(0, angles, im.shape[0], False))
# Create the ASTRA projector:
p = tvtomo.ProjectorASTRA2D(proj_geom,vol_geom)
# Define parameters and FISTA object that performs reconstruction:
#lam = 1**-14
f = tvtomo.FISTA(p, double(lam), fista_iter)
# Actual reconstruction (takes time):
im_rec = f.reconstruct(im.astype(float32), iter)
return im_rec.astype(float32)