Decoder that decompresses 2-D inputs by 2**num_compress_steps.

  Args:
    x: Tensor of shape [batch, compress_height, compress_width, channels].
    hparams: HParams.
    name: string, variable scope.

  Returns:
    Tensor of shape [batch, height, width, hparams.hidden_size].

def decompress_decoder_2d(x, hparams, name=None):
  """Decoder that decompresses 2-D inputs by 2**num_compress_steps.

  Args:
    x: Tensor of shape [batch, compress_height, compress_width, channels].
    hparams: HParams.
    name: string, variable scope.

  Returns:
    Tensor of shape [batch, height, width, hparams.hidden_size].
  """
  return decompress_decoder(x, hparams,
                            strides=(2, 2),
                            kernel=(hparams.kernel_size, hparams.kernel_size),
                            name=name)