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: output pixdim info specified by user
  set to None for using the original pixdim in image header
  otherwise get_data() transforms image array according to this value.
  
  :return: a tuple of pixdims, with each element as pixdims
      of an image file
code: def output_pixdim(self):
      """
      output pixdim info specified by user
      set to None for using the original pixdim in image header
      otherwise get_data() transforms image array according to this value.
  
      :return: a tuple of pixdims, with each element as pixdims
          of an image file
      """
      tf.logging.warning("resampling 2D images not implemented")
      return (None,) * len(self.file_path)
  
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 12 for calling the SpatialImage2D obj's underlying member method code with example usage: obj.output_pixdim() and returns: unknown