def _build_faster_rcnn_model()

in research/object_detection/builders/model_builder.py [0:0]


def _build_faster_rcnn_model(frcnn_config, is_training, add_summaries):
  """Builds a Faster R-CNN or R-FCN detection model based on the model config.

  Builds R-FCN model if the second_stage_box_predictor in the config is of type
  `rfcn_box_predictor` else builds a Faster R-CNN model.

  Args:
    frcnn_config: A faster_rcnn.proto object containing the config for the
      desired FasterRCNNMetaArch or RFCNMetaArch.
    is_training: True if this model is being built for training purposes.
    add_summaries: Whether to add tf summaries in the model.

  Returns:
    FasterRCNNMetaArch based on the config.

  Raises:
    ValueError: If frcnn_config.type is not recognized (i.e. not registered in
      model_class_map).
  """
  num_classes = frcnn_config.num_classes
  image_resizer_fn = image_resizer_builder.build(frcnn_config.image_resizer)
  _check_feature_extractor_exists(frcnn_config.feature_extractor.type)
  is_keras = tf_version.is_tf2()

  if is_keras:
    feature_extractor = _build_faster_rcnn_keras_feature_extractor(
        frcnn_config.feature_extractor, is_training,
        inplace_batchnorm_update=frcnn_config.inplace_batchnorm_update)
  else:
    feature_extractor = _build_faster_rcnn_feature_extractor(
        frcnn_config.feature_extractor, is_training,
        inplace_batchnorm_update=frcnn_config.inplace_batchnorm_update)

  number_of_stages = frcnn_config.number_of_stages
  first_stage_anchor_generator = anchor_generator_builder.build(
      frcnn_config.first_stage_anchor_generator)

  first_stage_target_assigner = target_assigner.create_target_assigner(
      'FasterRCNN',
      'proposal',
      use_matmul_gather=frcnn_config.use_matmul_gather_in_matcher)
  first_stage_atrous_rate = frcnn_config.first_stage_atrous_rate
  if is_keras:
    first_stage_box_predictor_arg_scope_fn = (
        hyperparams_builder.KerasLayerHyperparams(
            frcnn_config.first_stage_box_predictor_conv_hyperparams))
  else:
    first_stage_box_predictor_arg_scope_fn = hyperparams_builder.build(
        frcnn_config.first_stage_box_predictor_conv_hyperparams, is_training)
  first_stage_box_predictor_kernel_size = (
      frcnn_config.first_stage_box_predictor_kernel_size)
  first_stage_box_predictor_depth = frcnn_config.first_stage_box_predictor_depth
  first_stage_minibatch_size = frcnn_config.first_stage_minibatch_size
  use_static_shapes = frcnn_config.use_static_shapes and (
      frcnn_config.use_static_shapes_for_eval or is_training)
  first_stage_sampler = sampler.BalancedPositiveNegativeSampler(
      positive_fraction=frcnn_config.first_stage_positive_balance_fraction,
      is_static=(frcnn_config.use_static_balanced_label_sampler and
                 use_static_shapes))
  first_stage_max_proposals = frcnn_config.first_stage_max_proposals
  if (frcnn_config.first_stage_nms_iou_threshold < 0 or
      frcnn_config.first_stage_nms_iou_threshold > 1.0):
    raise ValueError('iou_threshold not in [0, 1.0].')
  if (is_training and frcnn_config.second_stage_batch_size >
      first_stage_max_proposals):
    raise ValueError('second_stage_batch_size should be no greater than '
                     'first_stage_max_proposals.')
  first_stage_non_max_suppression_fn = functools.partial(
      post_processing.batch_multiclass_non_max_suppression,
      score_thresh=frcnn_config.first_stage_nms_score_threshold,
      iou_thresh=frcnn_config.first_stage_nms_iou_threshold,
      max_size_per_class=frcnn_config.first_stage_max_proposals,
      max_total_size=frcnn_config.first_stage_max_proposals,
      use_static_shapes=use_static_shapes,
      use_partitioned_nms=frcnn_config.use_partitioned_nms_in_first_stage,
      use_combined_nms=frcnn_config.use_combined_nms_in_first_stage)
  first_stage_loc_loss_weight = (
      frcnn_config.first_stage_localization_loss_weight)
  first_stage_obj_loss_weight = frcnn_config.first_stage_objectness_loss_weight

  initial_crop_size = frcnn_config.initial_crop_size
  maxpool_kernel_size = frcnn_config.maxpool_kernel_size
  maxpool_stride = frcnn_config.maxpool_stride

  second_stage_target_assigner = target_assigner.create_target_assigner(
      'FasterRCNN',
      'detection',
      use_matmul_gather=frcnn_config.use_matmul_gather_in_matcher)
  if is_keras:
    second_stage_box_predictor = box_predictor_builder.build_keras(
        hyperparams_builder.KerasLayerHyperparams,
        freeze_batchnorm=False,
        inplace_batchnorm_update=False,
        num_predictions_per_location_list=[1],
        box_predictor_config=frcnn_config.second_stage_box_predictor,
        is_training=is_training,
        num_classes=num_classes)
  else:
    second_stage_box_predictor = box_predictor_builder.build(
        hyperparams_builder.build,
        frcnn_config.second_stage_box_predictor,
        is_training=is_training,
        num_classes=num_classes)
  second_stage_batch_size = frcnn_config.second_stage_batch_size
  second_stage_sampler = sampler.BalancedPositiveNegativeSampler(
      positive_fraction=frcnn_config.second_stage_balance_fraction,
      is_static=(frcnn_config.use_static_balanced_label_sampler and
                 use_static_shapes))
  (second_stage_non_max_suppression_fn, second_stage_score_conversion_fn
  ) = post_processing_builder.build(frcnn_config.second_stage_post_processing)
  second_stage_localization_loss_weight = (
      frcnn_config.second_stage_localization_loss_weight)
  second_stage_classification_loss = (
      losses_builder.build_faster_rcnn_classification_loss(
          frcnn_config.second_stage_classification_loss))
  second_stage_classification_loss_weight = (
      frcnn_config.second_stage_classification_loss_weight)
  second_stage_mask_prediction_loss_weight = (
      frcnn_config.second_stage_mask_prediction_loss_weight)

  hard_example_miner = None
  if frcnn_config.HasField('hard_example_miner'):
    hard_example_miner = losses_builder.build_hard_example_miner(
        frcnn_config.hard_example_miner,
        second_stage_classification_loss_weight,
        second_stage_localization_loss_weight)

  crop_and_resize_fn = (
      spatial_ops.multilevel_matmul_crop_and_resize
      if frcnn_config.use_matmul_crop_and_resize
      else spatial_ops.multilevel_native_crop_and_resize)
  clip_anchors_to_image = (
      frcnn_config.clip_anchors_to_image)

  common_kwargs = {
      'is_training':
          is_training,
      'num_classes':
          num_classes,
      'image_resizer_fn':
          image_resizer_fn,
      'feature_extractor':
          feature_extractor,
      'number_of_stages':
          number_of_stages,
      'first_stage_anchor_generator':
          first_stage_anchor_generator,
      'first_stage_target_assigner':
          first_stage_target_assigner,
      'first_stage_atrous_rate':
          first_stage_atrous_rate,
      'first_stage_box_predictor_arg_scope_fn':
          first_stage_box_predictor_arg_scope_fn,
      'first_stage_box_predictor_kernel_size':
          first_stage_box_predictor_kernel_size,
      'first_stage_box_predictor_depth':
          first_stage_box_predictor_depth,
      'first_stage_minibatch_size':
          first_stage_minibatch_size,
      'first_stage_sampler':
          first_stage_sampler,
      'first_stage_non_max_suppression_fn':
          first_stage_non_max_suppression_fn,
      'first_stage_max_proposals':
          first_stage_max_proposals,
      'first_stage_localization_loss_weight':
          first_stage_loc_loss_weight,
      'first_stage_objectness_loss_weight':
          first_stage_obj_loss_weight,
      'second_stage_target_assigner':
          second_stage_target_assigner,
      'second_stage_batch_size':
          second_stage_batch_size,
      'second_stage_sampler':
          second_stage_sampler,
      'second_stage_non_max_suppression_fn':
          second_stage_non_max_suppression_fn,
      'second_stage_score_conversion_fn':
          second_stage_score_conversion_fn,
      'second_stage_localization_loss_weight':
          second_stage_localization_loss_weight,
      'second_stage_classification_loss':
          second_stage_classification_loss,
      'second_stage_classification_loss_weight':
          second_stage_classification_loss_weight,
      'hard_example_miner':
          hard_example_miner,
      'add_summaries':
          add_summaries,
      'crop_and_resize_fn':
          crop_and_resize_fn,
      'clip_anchors_to_image':
          clip_anchors_to_image,
      'use_static_shapes':
          use_static_shapes,
      'resize_masks':
          frcnn_config.resize_masks,
      'return_raw_detections_during_predict':
          frcnn_config.return_raw_detections_during_predict,
      'output_final_box_features':
          frcnn_config.output_final_box_features,
      'output_final_box_rpn_features':
          frcnn_config.output_final_box_rpn_features,
  }

  if ((not is_keras and isinstance(second_stage_box_predictor,
                                   rfcn_box_predictor.RfcnBoxPredictor)) or
      (is_keras and
       isinstance(second_stage_box_predictor,
                  rfcn_keras_box_predictor.RfcnKerasBoxPredictor))):
    return rfcn_meta_arch.RFCNMetaArch(
        second_stage_rfcn_box_predictor=second_stage_box_predictor,
        **common_kwargs)
  elif frcnn_config.HasField('context_config'):
    context_config = frcnn_config.context_config
    common_kwargs.update({
        'attention_bottleneck_dimension':
            context_config.attention_bottleneck_dimension,
        'attention_temperature':
            context_config.attention_temperature,
        'use_self_attention':
            context_config.use_self_attention,
        'use_long_term_attention':
            context_config.use_long_term_attention,
        'self_attention_in_sequence':
            context_config.self_attention_in_sequence,
        'num_attention_heads':
            context_config.num_attention_heads,
        'num_attention_layers':
            context_config.num_attention_layers,
        'attention_position':
            context_config.attention_position
    })
    return context_rcnn_meta_arch.ContextRCNNMetaArch(
        initial_crop_size=initial_crop_size,
        maxpool_kernel_size=maxpool_kernel_size,
        maxpool_stride=maxpool_stride,
        second_stage_mask_rcnn_box_predictor=second_stage_box_predictor,
        second_stage_mask_prediction_loss_weight=(
            second_stage_mask_prediction_loss_weight),
        **common_kwargs)
  else:
    return faster_rcnn_meta_arch.FasterRCNNMetaArch(
        initial_crop_size=initial_crop_size,
        maxpool_kernel_size=maxpool_kernel_size,
        maxpool_stride=maxpool_stride,
        second_stage_mask_rcnn_box_predictor=second_stage_box_predictor,
        second_stage_mask_prediction_loss_weight=(
            second_stage_mask_prediction_loss_weight),
        **common_kwargs)