code: def transform_from_displacement_field(field):
      
      if not isinstance(field, iio.ANTsImage):
          raise ValueError('field must be ANTsImage type')
      libfn = utils.get_lib_fn('antsTransformFromDisplacementFieldF%i'%field.dimension)
      field = field.clone('float')
      txptr = libfn(field.pointer)
docs: Convert deformation field (multiChannel image) to ANTsTransform
  
      ANTsR function: `antsrTransformFromDisplacementField`
  
      Arguments
      ---------
      field : ANTsImage
          deformation field as multi-channel ANTsImage
  
      Returns
      -------
      ANTsImage
  
      Example
      -------
      >>> import ants
      >>> fi = ants.image_read(ants.get_ants_data('r16') )
      >>> mi = ants.image_read(ants.get_ants_data('r64') )
      >>> fi = ants.resample_image(fi,(60,60),1,0)
      >>> mi = ants.resample_image(mi,(60,60),1,0) # speed up
      >>> mytx = ants.registration(fixed=fi, moving=mi, type_of_transform = ('SyN') )
      >>> compfield = ants.compose_transforms_to_field( fi, mytx['fwd'] )
      >>> atx = ants.transform_from_displacement_field( compfield )