hparams fo 12 layer big 1d model for imagenet 64x64.

def imagetransformer1d_base_8l_64by64():
  """hparams fo 12 layer big 1d model for imagenet 64x64."""
  hparams = image_transformer_base()
  hparams.num_heads = 8
  hparams.hidden_size = 512
  hparams.filter_size = 2048
  hparams.num_decoder_layers = 8
  hparams.batch_size = 1
  hparams.block_length = 512
  hparams.block_width = 768
  hparams.layer_prepostprocess_dropout = 0.1
  hparams.max_length = 14000
  hparams.unconditional = int(False)
  return hparams