code: def get_image_cnn_encoder(config: ImageLoadedCnnEncoderConfig) -> 'Encoder':
      
  
      encoders = list()  # type: List[Encoder]
      max_seq_len = config.encoded_seq_len
      if not config.no_global_descriptor:
          max_seq_len += 1
      encoders.append(get_positional_embedding(config.positional_embedding_type,
                                               config.num_embed,
                                               max_seq_len=max_seq_len,
                                               fixed_pos_embed_scale_up_input=False,
                                               fixed_pos_embed_scale_down_positions=True,
                                               prefix=C.SOURCE_POSITIONAL_EMBEDDING_PREFIX))
      encoders.append(ImageLoadedCnnEncoder(config=config))
      return EncoderSequence(encoders)
docs: Creates a image encoder.
  
      :param config: Configuration for image encoder.
      :return: Encoder instance.