class_docstr: Base class for problems with images.
class_docstr_tok: ["Base","class","for","problems","with","images","."]
code: def example_reading_spec(self):
      data_fields = {
          "image/encoded": tf.FixedLenFeature((), tf.string),
          "image/format": tf.FixedLenFeature((), tf.string),
      }
  
      data_items_to_decoders = {
          "inputs": contrib.slim().tfexample_decoder.Image(
              image_key="image/encoded",
              format_key="image/format",
              channels=self.num_channels,
          ),
      }
  
      return data_fields, data_items_to_decoders
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import io
  import os
  import numpy
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_encoder
  from tensor2tensor.layers import common_layers
  from tensor2tensor.layers import modalities
  from tensor2tensor.utils import contrib
  from tensor2tensor.utils import metrics
  import tensorflow.compat.v1
label_desc: Use image node_id 3 for calling the ImageProblem obj's underlying member method code with example usage: obj.example_reading_spec() and returns: data_fields,  data_items_to_decoders