def main():
## Initial print
print("\n")
print("##########################################################")
print("############# HIERARCHICAL BACKPROJECTION #############")
print("##########################################################")
print("\n")
## Get the startimg time of the reconstruction
time1 = time.time()
## Get input arguments
args = getArgs()
## Get input directory
pathin = args.pathin
if pathin[len(pathin) - 1] != "/":
pathin += "/"
if os.path.exists(pathin) is False:
sys.exit("\nERROR: input directory ", pathin, " does not exist!")
print("\nInput directory:\n", pathin)
## Get input sinogram
sinofile = pathin + args.sino
sino = io.readImage(sinofile)
nang, npix = sino.shape
print("\nSinogram to reconstruct:\n", sinofile)
print("Number of projection angles: ", nang)
print("Number of pixels: ", npix)
## Display sinogram
if args.plot is True:
dis.plot(sino, "Input sinogram")
## Getting projection geometry
if args.geometry == "0":
print("\nDealing with equiangular projections distributed between 0 and" + " 180 degrees ---> [0,180)")
angles = np.arange(nang).astype(myfloat)
angles[:] = (angles * 180.0) / myfloat(nang)
else:
geometryfile = pathin + args.geometry
print("\nReading list of projection angles: ", geometryfile)
angles = np.fromfile(geometryfile, sep="\t")
if args.plot is True:
print("\nProjection angles:\n", angles)
## Enable edge padding
if args.edge_pad is True:
sino = proc.edgePadding(sino, 0.5)
i1 = int((sino.shape[1] - npix) * 0.5)
i2 = i1 + npix
npix = sino.shape[1]
if args.plot is True:
dis.plot(sino, "Edge padded sinogram")
## Set center of rotation axis
if args.ctr == -1:
ctr = proc.searchCtrRot(sino, None, "a")
elif args.ctr == 0:
ctr = 0.5 * npix
else:
ctr = args.ctr
sino[:, :] = proc.sinoRotAxisCorrect(sino, ctr)
print("Center of rotation axis placed at pixel: ", ctr)
print("Center of rotation correction done! ")
if args.edge_pad is True and ctr != 0.0:
ctr += i1
## External sinogram filtering
filt = args.filt
if filt not in filt_list:
print(
"\nERROR: filter named: ', filt,' does not exist!\n \
Use one of the following available filters:\n \
'none' , 'ramp' , 'shlo' , 'hann' , 'hamm' , \n \
'parz' , 'lancz' "
)
print("\nSelected filter: ", filt)
if filt == "none":
filter_name = "none"
elif filt == "ramp":
filter_name = "ramp"
elif filt == "hann":
filter_name = "hanning"
elif filt == "hamm":
filter_name = "hamming"
sino = fil.filter_fft(sino, filter_name, 0)
sino *= 4.0 / myfloat(npix)
if args.plot is True:
dis.plot(sino, "Filtered sinogram")
## Set number of pixels of the reconstructed image
if args.npix_im is None:
npix_im = npix
else:
npix_im = args.npix_im
if args.base_size == 0:
base_size = npix
else:
base_size = args.base_size
if args.down_size == 0:
down_size = npix
else:
down_size = args.down_size
## Set parameters
print("\nFHBP parameter setting:")
print("Number image pixels: ", npix_im)
print("Base size: ", base_size)
print("Downsampling size: ", down_size)
print("Ratio sinogram / image sampling: ", args.sampl_ratio)
param = np.array([npix_im, base_size, down_size, args.sampl_ratio])
## Reconstruction with regridding method
time_rec1 = time.time()
reco = fhbp.backproj(sino.astype(myfloat), angles.astype(myfloat), param.astype(myfloat))
time_rec2 = time.time()
## Crop reconstruction
if args.edge_pad:
reco = reco[i1:i2, i1:i2]
## Rotate and flip reconstruction
reco[:, :] = reco[:, ::-1]
## Display reconstruction
if args.plot is True:
dis.plot(reco, "Reconstruction")
## Save reconstruction
write_reconstruction(reco, pathin, args)
## Time elapsed and memory usage for the reconstruction
time2 = time.time()
print("\nTime elapsed for the back-projection: ", time_rec2 - time_rec1, " s")
print("Total time elapsed: ", time2 - time1, " s")
print("\n")
print("########################################")
print("#### FHBP BACKPROJECTION DONE ! ####")
print("########################################")
print("\n")
