old_contents: #!/usr/bin/env python
  #=========================================================================
  #
  #  Copyright Insight Software Consortium
  #
  #  Licensed under the Apache License, Version 2.0 (the "License");
  #  you may not use this file except in compliance with the License.
  #  You may obtain a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0.txt
  #
  #  Unless required by applicable law or agreed to in writing, software
  #  distributed under the License is distributed on an "AS IS" BASIS,
  #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #  See the License for the specific language governing permissions and
  #  limitations under the License.
  #
  #=========================================================================
  
  from __future__ import print_function
  
  import SimpleITK as sitk
  import sys
  import os
  
  
  def command_iteration(filter) :
      print("{0:3} = {1:10.5f}".format(filter.GetElapsedIterations(),
                                      filter.GetMetric()))
  
  if len ( sys.argv ) < 4:
      print( "Usage: {0} <fixedImageFilter> <movingImageFile> <outputTransformFile>".format(sys.argv[0]))
      sys.exit ( 1 )
  
  
  fixed = sitk.ReadImage(sys.argv[1], sitk.sitkFloat32)
  
  moving = sitk.ReadImage(sys.argv[2], sitk.sitkFloat32)
  
  
  matcher = sitk.HistogramMatchingImageFilter()
  matcher.SetNumberOfHistogramLevels(1024)
  matcher.SetNumberOfMatchPoints(7)
  matcher.ThresholdAtMeanIntensityOn()
  moving = matcher.Execute(moving,fixed)
  
  demons = sitk.DemonsRegistrationFilter()
  demons.SetNumberOfIterations( 50 )
  demons.SetStandardDeviations( 1.0 )
  
  demons.AddCommand( sitk.sitkIterationEvent, lambda: command_iteration(demons) )
  
  displacementField = demons.Execute( fixed, moving )
  
  
  print("-------")
  print("Number Of Iterations: {0}".format(demons.GetElapsedIterations()))
  print(" RMS: {0}".format(demons.GetRMSChange()))
  
  outTx = sitk.DisplacementFieldTransform( displacementField )
  
  sitk.WriteTransform(outTx, sys.argv[3])
  
  if ( not "SITK_NOSHOW" in os.environ ):
  
      resampler = sitk.ResampleImageFilter()
      resampler.SetReferenceImage(fixed);
      resampler.SetInterpolator(sitk.sitkLinear)
      resampler.SetDefaultPixelValue(100)
      resampler.SetTransform(outTx)
  
      out = resampler.Execute(moving)
      simg1 = sitk.Cast(sitk.RescaleIntensity(fixed), sitk.sitkUInt8)
      simg2 = sitk.Cast(sitk.RescaleIntensity(out), sitk.sitkUInt8)
      cimg = sitk.Compose(simg1, simg2, simg1/2.+simg2/2.)
      sitk.Show( cimg, "DeformableRegistration1 Composition" )
  
new_contents: #!/usr/bin/env python
  #=========================================================================
  #
  #  Copyright Insight Software Consortium
  #
  #  Licensed under the Apache License, Version 2.0 (the "License");
  #  you may not use this file except in compliance with the License.
  #  You may obtain a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0.txt
  #
  #  Unless required by applicable law or agreed to in writing, software
  #  distributed under the License is distributed on an "AS IS" BASIS,
  #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #  See the License for the specific language governing permissions and
  #  limitations under the License.
  #
  #=========================================================================
  
  from __future__ import print_function
  
  import SimpleITK as sitk
  import sys
  import os
  
  
  def command_iteration(filter) :
      print("{0:3} = {1:10.5f}".format(filter.GetElapsedIterations(),
                                      filter.GetMetric()))
  
  if len ( sys.argv ) < 4:
      print( "Usage: {0} <fixedImageFilter> <movingImageFile> <outputTransformFile>".format(sys.argv[0]))
      sys.exit ( 1 )
  
  
  fixed = sitk.ReadImage(sys.argv[1], sitk.sitkFloat32)
  
  moving = sitk.ReadImage(sys.argv[2], sitk.sitkFloat32)
  
  
  matcher = sitk.HistogramMatchingImageFilter()
  matcher.SetNumberOfHistogramLevels(1024)
  matcher.SetNumberOfMatchPoints(7)
  matcher.ThresholdAtMeanIntensityOn()
  moving = matcher.Execute(moving,fixed)
  
  demons = sitk.DemonsRegistrationFilter()
  demons.SetNumberOfIterations( 50 )
  demons.SetStandardDeviations( 1.0 )
  
  demons.AddCommand( sitk.sitkIterationEvent, lambda: command_iteration(demons) )
  
  displacementField = demons.Execute( fixed, moving )
  
  
  print("-------")
  print("Number Of Iterations: {0}".format(demons.GetElapsedIterations()))
  print(" RMS: {0}".format(demons.GetRMSChange()))
  
  outTx = sitk.DisplacementFieldTransform( displacementField )
  
  sitk.WriteTransform(outTx, sys.argv[3])
  
  if ( not "SITK_NOSHOW" in os.environ ):
  
      resampler = sitk.ResampleImageFilter()
      resampler.SetReferenceImage(fixed);
      resampler.SetInterpolator(sitk.sitkLinear)
      resampler.SetDefaultPixelValue(100)
      resampler.SetTransform(outTx)
  
      out = resampler.Execute(moving)
      simg1 = sitk.Cast(sitk.RescaleIntensity(fixed), sitk.sitkUInt8)
      simg2 = sitk.Cast(sitk.RescaleIntensity(out), sitk.sitkUInt8)
      # Use the // floor division operator so that the pixel type is
      # the same for all three images which is the expectation for
      # the compose filter.
      cimg = sitk.Compose(simg1, simg2, simg1//2.+simg2//2.)
      sitk.Show( cimg, "DeformableRegistration1 Composition" )
  
subject: Use of floor division instead of regular division.