def main():
## Initial print
print('\n')
print('############################################################')
print('############# FORWARD HIERACHICAL PROJECTOR #############')
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 image and number of views
imgfile = args.image
image = io.readImage( pathin + imgfile )
npix = image.shape[0]
print('\nSinogram to reconstruct:\n', imgfile)
print('Number of pixels: ', npix)
## Display image
if args.plot is True:
dis.plot( image , 'Input image' )
## Get projection angle range
if args.geometry == '0' or args.geometry == '1':
if args.angle_range.find( ':' ) == -1:
angle_start = myfloat( args.angle_range )
angle_end = angle_start + 180.0
else:
angle_aux = args.angle_range.find( ':' )
angle_start = myfloat( angle_aux[0] )
angle_end = myfloat( angle_aux[1] )
print( '\nSelected angle range: [ ', angle_start,' , ', angle_end,' ]' )
## Get projection geometry
print( 'args.geometry = ', args.geometry)
if args.geometry == '0':
nang = args.nang
print('\nDealing with equiangular projections distributed between 0 and'
+' 180 degrees ---> [0,180)')
angles = create_equally_spaced_angles( nang , angle_start , angle_end )
elif args.geometry == '1':
nang = args.nang
angles = create_pseudo_polar_angles( nang ) * 180.0 / np.pi
print('\nDealing with equally sloped projections in [0,180)')
else:
geometryfile = pathin + args.geometry
print('\nReading list of projection angles: ', geometryfile)
angles = np.fromfile( geometryfile , sep="\t" )
nang = len( angles )
print('Number of projection angles: ', nang)
if args.plot is True:
print('\nProjection angles:\n', angles)
## Pad image to reach number of required sinogram pixels
if args.npix_s is not None:
npix_s = args.npix_s
else:
npix_s = npix
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 sinogram pixels: ' , npix_s )
print( 'Base size: ' , base_size )
print( 'Downsampling size: ' , down_size )
print( 'Ratio sinogram / image sampling: ' , args.sampl_ratio )
param = np.array( [ npix_s , base_size , down_size ,
args.sampl_ratio ] )
## Apply forward projection operator
time_rec1 = time.time()
sino = fhbp.forwproj( image.astype( myfloat ) , angles.astype( myfloat ) ,
param.astype( myfloat ) )
time_rec2 = time.time()
## Crop sinogram
if args.crop is True and npix_s > npix:
print( 'Sinogram cropping enabled')
i1 = int( 0.5 * ( npix_s - npix ) )
i2 = i1 + npix
sino = sino[::-1,i1:i2]
## Display sinogram
if args.plot is True:
dis.plot( sino , 'Sinogram' )
## Save sinogram
write_sinogram( sino , pathin , angles , args )
## Time elapsed to run the code
time2 = time.time()
print('\nTime elapsed to run the forward gridrec: ', time_rec2-time_rec1)
print('Total time elapsed for the run of the program: ', time2-time1)
print('\n')
print('#######################################')
print('#### FORWARD PROJECTION DONE ! ####')
print('#######################################')
print('\n')
