def model_fn(self, features, labels, mode):
"""Define Faster R-CNN model_fn used by TensorFlow Estimator."""
logging.info('Faster R-CNN model function action')
self.model = self.trainer.model
self.config = self.trainer.config
predict_result_dict = self.model(features, labels,
mode == tf.estimator.ModeKeys.TRAIN)
self.fine_tune_checkpoint_type = self.config.fine_tune_checkpoint_type
self.load_all_detection_checkpoint_vars = True
asg_map = self.model.restore_map(
fine_tune_checkpoint_type=self.fine_tune_checkpoint_type,
load_all_detection_checkpoint_vars=(
self.load_all_detection_checkpoint_vars))
self.fine_tune_checkpoint = self.config.fine_tune_checkpoint
available_var_map = (
variables_helper.get_variables_available_in_checkpoint(
asg_map, self.fine_tune_checkpoint, include_global_step=False))
tf.train.init_from_checkpoint(self.fine_tune_checkpoint,
available_var_map)
losses_dict = self.model.loss(
predict_result_dict,
features[fields.InputDataFields.true_image_shape])
losses = [loss_tensor for loss_tensor in losses_dict.values()]
total_loss = tf.add_n(losses, name='total_loss')
train_op = None
if mode == tf.estimator.ModeKeys.TRAIN:
global_step = tf.train.get_or_create_global_step()
self.optimizer, self.optimizer_summary_vars = TFOptimizer(
self.config.optimizer).get_real_optimizer(global_step)
trainable_variables = None
trainable_variables = slim.filter_variables(
tf.trainable_variables())
clip_gradients_value = None
summaries = None
train_op = slim.optimizers.optimize_loss(
loss=total_loss,
global_step=global_step,
learning_rate=None,
clip_gradients=clip_gradients_value,
optimizer=self.optimizer,
update_ops=self.model.updates(),
variables=trainable_variables,
summaries=summaries,
name='') # Preventing scope prefix on all variables.
eval_metric_ops = None
if mode == tf.estimator.ModeKeys.EVAL:
eval_metric_ops = self.valid_metrics(predict_result_dict, labels)
return tf.estimator.EstimatorSpec(mode=mode,
loss=total_loss,
train_op=train_op,
eval_metric_ops=eval_metric_ops)
def model_fn(features, labels, mode, params=None):
"""Constructs the object detection model.
Args:
features: Dictionary of feature tensors, returned from `input_fn`.
labels: Dictionary of groundtruth tensors if mode is TRAIN or EVAL,
otherwise None.
mode: Mode key from tf.estimator.ModeKeys.
params: Parameter dictionary passed from the estimator.
Returns:
An `EstimatorSpec` that encapsulates the model and its serving
configurations.
"""
params = params or {}
total_loss, train_op, detections, export_outputs = None, None, None, None
is_training = mode == tf.estimator.ModeKeys.TRAIN
# Make sure to set the Keras learning phase. True during training,
# False for inference.
tf.keras.backend.set_learning_phase(is_training)
# Set policy for mixed-precision training with Keras-based models.
if use_tpu and train_config.use_bfloat16:
from tensorflow.python.keras.engine import base_layer_utils # pylint: disable=g-import-not-at-top
# Enable v2 behavior, as `mixed_bfloat16` is only supported in TF 2.0.
base_layer_utils.enable_v2_dtype_behavior()
tf2.keras.mixed_precision.experimental.set_policy('mixed_bfloat16')
detection_model = detection_model_fn(is_training=is_training,
add_summaries=(not use_tpu))
scaffold_fn = None
if mode == tf.estimator.ModeKeys.TRAIN:
labels = unstack_batch(labels,
unpad_groundtruth_tensors=train_config.
unpad_groundtruth_tensors)
elif mode == tf.estimator.ModeKeys.EVAL:
# For evaling on train data, it is necessary to check whether groundtruth
# must be unpadded.
boxes_shape = (labels[fields.InputDataFields.groundtruth_boxes].
get_shape().as_list())
unpad_groundtruth_tensors = boxes_shape[
1] is not None and not use_tpu
labels = unstack_batch(
labels, unpad_groundtruth_tensors=unpad_groundtruth_tensors)
if mode in (tf.estimator.ModeKeys.TRAIN, tf.estimator.ModeKeys.EVAL):
provide_groundtruth(detection_model, labels)
preprocessed_images = features[fields.InputDataFields.image]
side_inputs = detection_model.get_side_inputs(features)
if use_tpu and train_config.use_bfloat16:
with tf.tpu.bfloat16_scope():
prediction_dict = detection_model.predict(
preprocessed_images,
features[fields.InputDataFields.true_image_shape],
**side_inputs)
prediction_dict = ops.bfloat16_to_float32_nested(
prediction_dict)
else:
prediction_dict = detection_model.predict(
preprocessed_images,
features[fields.InputDataFields.true_image_shape],
**side_inputs)
def postprocess_wrapper(args):
return detection_model.postprocess(args[0], args[1])
if mode in (tf.estimator.ModeKeys.EVAL, tf.estimator.ModeKeys.PREDICT):
if use_tpu and postprocess_on_cpu:
detections = tf.tpu.outside_compilation(
postprocess_wrapper,
(prediction_dict,
features[fields.InputDataFields.true_image_shape]))
else:
detections = postprocess_wrapper(
(prediction_dict,
features[fields.InputDataFields.true_image_shape]))
if mode == tf.estimator.ModeKeys.TRAIN:
load_pretrained = hparams.load_pretrained if hparams else False
if train_config.fine_tune_checkpoint and load_pretrained:
if not train_config.fine_tune_checkpoint_type:
# train_config.from_detection_checkpoint field is deprecated. For
# backward compatibility, set train_config.fine_tune_checkpoint_type
# based on train_config.from_detection_checkpoint.
if train_config.from_detection_checkpoint:
train_config.fine_tune_checkpoint_type = 'detection'
else:
train_config.fine_tune_checkpoint_type = 'classification'
asg_map = detection_model.restore_map(
fine_tune_checkpoint_type=train_config.
fine_tune_checkpoint_type,
load_all_detection_checkpoint_vars=(
train_config.load_all_detection_checkpoint_vars))
available_var_map = (
variables_helper.get_variables_available_in_checkpoint(
asg_map,
train_config.fine_tune_checkpoint,
include_global_step=False))
if use_tpu:
def tpu_scaffold():
tf.train.init_from_checkpoint(
train_config.fine_tune_checkpoint,
available_var_map)
return tf.train.Scaffold()
scaffold_fn = tpu_scaffold
else:
tf.train.init_from_checkpoint(
train_config.fine_tune_checkpoint, available_var_map)
if mode in (tf.estimator.ModeKeys.TRAIN, tf.estimator.ModeKeys.EVAL):
if (mode == tf.estimator.ModeKeys.EVAL
and eval_config.use_dummy_loss_in_eval):
total_loss = tf.constant(1.0)
losses_dict = {'Loss/total_loss': total_loss}
else:
losses_dict = detection_model.loss(
prediction_dict,
features[fields.InputDataFields.true_image_shape])
losses = [loss_tensor for loss_tensor in losses_dict.values()]
if train_config.add_regularization_loss:
regularization_losses = detection_model.regularization_losses(
)
if use_tpu and train_config.use_bfloat16:
regularization_losses = ops.bfloat16_to_float32_nested(
regularization_losses)
if regularization_losses:
regularization_loss = tf.add_n(
regularization_losses, name='regularization_loss')
losses.append(regularization_loss)
losses_dict[
'Loss/regularization_loss'] = regularization_loss
total_loss = tf.add_n(losses, name='total_loss')
losses_dict['Loss/total_loss'] = total_loss
if 'graph_rewriter_config' in configs:
graph_rewriter_fn = graph_rewriter_builder.build(
configs['graph_rewriter_config'], is_training=is_training)
graph_rewriter_fn()
# TODO(rathodv): Stop creating optimizer summary vars in EVAL mode once we
# can write learning rate summaries on TPU without host calls.
global_step = tf.train.get_or_create_global_step()
training_optimizer, optimizer_summary_vars = optimizer_builder.build(
train_config.optimizer)
if mode == tf.estimator.ModeKeys.TRAIN:
if use_tpu:
training_optimizer = tf.tpu.CrossShardOptimizer(
training_optimizer)
# Optionally freeze some layers by setting their gradients to be zero.
trainable_variables = None
include_variables = (train_config.update_trainable_variables
if train_config.update_trainable_variables
else None)
exclude_variables = (train_config.freeze_variables
if train_config.freeze_variables else None)
trainable_variables = slim.filter_variables(
tf.trainable_variables(),
include_patterns=include_variables,
exclude_patterns=exclude_variables)
clip_gradients_value = None
if train_config.gradient_clipping_by_norm > 0:
clip_gradients_value = train_config.gradient_clipping_by_norm
if not use_tpu:
for var in optimizer_summary_vars:
tf.summary.scalar(var.op.name, var)
summaries = [] if use_tpu else None
if train_config.summarize_gradients:
summaries = [
'gradients', 'gradient_norm', 'global_gradient_norm'
]
train_op = slim.optimizers.optimize_loss(
loss=total_loss,
global_step=global_step,
learning_rate=None,
clip_gradients=clip_gradients_value,
optimizer=training_optimizer,
update_ops=detection_model.updates(),
variables=trainable_variables,
summaries=summaries,
name='') # Preventing scope prefix on all variables.
if mode == tf.estimator.ModeKeys.PREDICT:
exported_output = exporter_lib.add_output_tensor_nodes(detections)
export_outputs = {
tf.saved_model.signature_constants.PREDICT_METHOD_NAME:
tf.estimator.export.PredictOutput(exported_output)
}
eval_metric_ops = None
scaffold = None
if mode == tf.estimator.ModeKeys.EVAL:
class_agnostic = (fields.DetectionResultFields.detection_classes
not in detections)
groundtruth = _prepare_groundtruth_for_eval(
detection_model, class_agnostic,
eval_input_config.max_number_of_boxes)
use_original_images = fields.InputDataFields.original_image in features
if use_original_images:
eval_images = features[fields.InputDataFields.original_image]
true_image_shapes = tf.slice(
features[fields.InputDataFields.true_image_shape], [0, 0],
[-1, 3])
original_image_spatial_shapes = features[
fields.InputDataFields.original_image_spatial_shape]
else:
eval_images = features[fields.InputDataFields.image]
true_image_shapes = None
original_image_spatial_shapes = None
eval_dict = eval_util.result_dict_for_batched_example(
eval_images,
features[inputs.HASH_KEY],
detections,
groundtruth,
class_agnostic=class_agnostic,
scale_to_absolute=True,
original_image_spatial_shapes=original_image_spatial_shapes,
true_image_shapes=true_image_shapes)
if fields.InputDataFields.image_additional_channels in features:
eval_dict[fields.InputDataFields.
image_additional_channels] = features[
fields.InputDataFields.image_additional_channels]
if class_agnostic:
category_index = label_map_util.create_class_agnostic_category_index(
)
else:
category_index = label_map_util.create_category_index_from_labelmap(
eval_input_config.label_map_path)
vis_metric_ops = None
if not use_tpu and use_original_images:
keypoint_edges = [(kp.start, kp.end)
for kp in eval_config.keypoint_edge]
eval_metric_op_vis = vis_utils.VisualizeSingleFrameDetections(
category_index,
max_examples_to_draw=eval_config.num_visualizations,
max_boxes_to_draw=eval_config.max_num_boxes_to_visualize,
min_score_thresh=eval_config.min_score_threshold,
use_normalized_coordinates=False,
keypoint_edges=keypoint_edges or None)
vis_metric_ops = eval_metric_op_vis.get_estimator_eval_metric_ops(
eval_dict)
# Eval metrics on a single example.
eval_metric_ops = eval_util.get_eval_metric_ops_for_evaluators(
eval_config, list(category_index.values()), eval_dict)
for loss_key, loss_tensor in iter(losses_dict.items()):
eval_metric_ops[loss_key] = tf.metrics.mean(loss_tensor)
for var in optimizer_summary_vars:
eval_metric_ops[var.op.name] = (var, tf.no_op())
if vis_metric_ops is not None:
eval_metric_ops.update(vis_metric_ops)
eval_metric_ops = {str(k): v for k, v in eval_metric_ops.items()}
if eval_config.use_moving_averages:
variable_averages = tf.train.ExponentialMovingAverage(0.0)
variables_to_restore = variable_averages.variables_to_restore()
keep_checkpoint_every_n_hours = (
train_config.keep_checkpoint_every_n_hours)
saver = tf.train.Saver(
variables_to_restore,
keep_checkpoint_every_n_hours=keep_checkpoint_every_n_hours
)
scaffold = tf.train.Scaffold(saver=saver)
# EVAL executes on CPU, so use regular non-TPU EstimatorSpec.
if use_tpu and mode != tf.estimator.ModeKeys.EVAL:
return tf.estimator.tpu.TPUEstimatorSpec(
mode=mode,
scaffold_fn=scaffold_fn,
predictions=detections,
loss=total_loss,
train_op=train_op,
eval_metrics=eval_metric_ops,
export_outputs=export_outputs)
else:
if scaffold is None:
keep_checkpoint_every_n_hours = (
train_config.keep_checkpoint_every_n_hours)
saver = tf.train.Saver(
sharded=True,
keep_checkpoint_every_n_hours=keep_checkpoint_every_n_hours,
save_relative_paths=True)
tf.add_to_collection(tf.GraphKeys.SAVERS, saver)
scaffold = tf.train.Scaffold(saver=saver)
return tf.estimator.EstimatorSpec(mode=mode,
predictions=detections,
loss=total_loss,
train_op=train_op,
eval_metric_ops=eval_metric_ops,
export_outputs=export_outputs,
scaffold=scaffold)
def filter_train_vars(train_vars: List[tf.Variable],
inc_patterns: Optional[List[str]],
exc_patterns: Optional[List[str]]):
return slim.filter_variables(train_vars,
include_patterns=inc_patterns,
exclude_patterns=exc_patterns)
