class_docstr: 2D images, axcodes specifications are ignored when
  loading. (Resampling to new pixdims is currently not supported).
class_docstr_tok: ["2D","images",",","axcodes","specifications","are","ignored","when","loading",".","(","Resampling","to","new","pixdims","is","currently","not","supported",")","."]
docstr: affine info from the image header.
  
  :return: a tuple of affine, with each element as an affine
      matrix of an image file
docstr_tok: ["affine","info","from","the","image","header",".",":","return",":","a","tuple","of","affine",",","with","each","element","as","an","affine","matrix","of","an","image","file"]
code: def original_affine(self):
      """
      affine info from the image header.
  
      :return: a tuple of affine, with each element as an affine
          matrix of an image file
      """
      try:
          assert self._original_affine[0] is not None
      except (IndexError, AssertionError):
          self._load_header()
      return self._original_affine
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  from abc import ABCMeta, abstractmethod
  import nibabel
  import numpy
  import tensorflow
  from six import with_metaclass, string_types
  import niftynet.io.misc_io
  from niftynet.io.image_loader import load_image_obj
  from niftynet.io.misc_io import resolve_file_name, dtype_casting
  from niftynet.utilities.niftynet_global_config import NiftyNetGlobalConfig
label_desc: Use image node_id 7 for calling the SpatialImage2D obj's underlying member method code with example usage: obj.original_affine() and returns: self