def restore_ckpt(sess, ckpt_path, ema_decay=0.9998, export_ckpt=None):
"""Restore variables from a given checkpoint.
Args:
sess: a tf session for restoring or exporting models.
ckpt_path: the path of the checkpoint. Can be a file path or a folder path.
ema_decay: ema decay rate. If None or zero or negative value, disable ema.
export_ckpt: whether to export the restored model.
"""
sess.run(tf.global_variables_initializer())
if tf.io.gfile.isdir(ckpt_path):
ckpt_path = tf.train.latest_checkpoint(ckpt_path)
if ema_decay > 0:
ema = tf.train.ExponentialMovingAverage(decay=0.0)
ema_vars = utils.get_ema_vars()
var_dict = ema.variables_to_restore(ema_vars)
ema_assign_op = ema.apply(ema_vars)
else:
var_dict = utils.get_ema_vars()
ema_assign_op = None
tf.train.get_or_create_global_step()
sess.run(tf.global_variables_initializer())
saver = tf.train.Saver(var_dict, max_to_keep=1)
if ckpt_path == '_':
logging.info('Running test: do not load any ckpt.')
return
# Restore all variables from ckpt.
saver.restore(sess, ckpt_path)
if export_ckpt:
print('export model to {}'.format(export_ckpt))
if ema_assign_op is not None:
sess.run(ema_assign_op)
saver = tf.train.Saver(max_to_keep=1, save_relative_paths=True)
saver.save(sess, export_ckpt)
def _model_fn(features, labels, mode, params, model, variable_filter_fn=None):
"""Model definition entry.
Args:
features: the input image tensor with shape [batch_size, height, width, 3].
The height and width are fixed and equal.
labels: the input labels in a dictionary. The labels include class targets
and box targets which are dense label maps. The labels are generated from
get_input_fn function in data/dataloader.py
mode: the mode of TPUEstimator including TRAIN and EVAL.
params: the dictionary defines hyperparameters of model. The default
settings are in default_hparams function in this file.
model: the model outputs class logits and box regression outputs.
variable_filter_fn: the filter function that takes trainable_variables and
returns the variable list after applying the filter rule.
Returns:
tpu_spec: the TPUEstimatorSpec to run training, evaluation, or prediction.
Raises:
RuntimeError: if both ckpt and backbone_ckpt are set.
"""
is_tpu = params['strategy'] == 'tpu'
if params['img_summary_steps']:
utils.image('input_image', features, is_tpu)
training_hooks = []
params['is_training_bn'] = (mode == tf.estimator.ModeKeys.TRAIN)
if params['use_keras_model']:
def model_fn(inputs):
model = efficientdet_keras.EfficientDetNet(
config=hparams_config.Config(params))
cls_out_list, box_out_list = model(inputs, params['is_training_bn'])
cls_outputs, box_outputs = {}, {}
for i in range(params['min_level'], params['max_level'] + 1):
cls_outputs[i] = cls_out_list[i - params['min_level']]
box_outputs[i] = box_out_list[i - params['min_level']]
return cls_outputs, box_outputs
else:
model_fn = functools.partial(model, config=hparams_config.Config(params))
precision = utils.get_precision(params['strategy'], params['mixed_precision'])
cls_outputs, box_outputs = utils.build_model_with_precision(
precision, model_fn, features, params['is_training_bn'])
levels = cls_outputs.keys()
for level in levels:
cls_outputs[level] = tf.cast(cls_outputs[level], tf.float32)
box_outputs[level] = tf.cast(box_outputs[level], tf.float32)
# Set up training loss and learning rate.
update_learning_rate_schedule_parameters(params)
global_step = tf.train.get_or_create_global_step()
learning_rate = learning_rate_schedule(params, global_step)
# cls_loss and box_loss are for logging. only total_loss is optimized.
det_loss, cls_loss, box_loss = detection_loss(
cls_outputs, box_outputs, labels, params)
reg_l2loss = reg_l2_loss(params['weight_decay'])
total_loss = det_loss + reg_l2loss
if mode == tf.estimator.ModeKeys.TRAIN:
utils.scalar('lrn_rate', learning_rate, is_tpu)
utils.scalar('trainloss/cls_loss', cls_loss, is_tpu)
utils.scalar('trainloss/box_loss', box_loss, is_tpu)
utils.scalar('trainloss/det_loss', det_loss, is_tpu)
utils.scalar('trainloss/reg_l2_loss', reg_l2loss, is_tpu)
utils.scalar('trainloss/loss', total_loss, is_tpu)
train_epochs = tf.cast(global_step, tf.float32) / params['steps_per_epoch']
utils.scalar('train_epochs', train_epochs, is_tpu)
moving_average_decay = params['moving_average_decay']
if moving_average_decay:
ema = tf.train.ExponentialMovingAverage(
decay=moving_average_decay, num_updates=global_step)
ema_vars = utils.get_ema_vars()
if mode == tf.estimator.ModeKeys.TRAIN:
if params['optimizer'].lower() == 'sgd':
optimizer = tf.train.MomentumOptimizer(
learning_rate, momentum=params['momentum'])
elif params['optimizer'].lower() == 'adam':
optimizer = tf.train.AdamOptimizer(learning_rate)
else:
raise ValueError('optimizers should be adam or sgd')
if is_tpu:
optimizer = tf.tpu.CrossShardOptimizer(optimizer)
# Batch norm requires update_ops to be added as a train_op dependency.
update_ops = tf.get_collection(tf.GraphKeys.UPDATE_OPS)
var_list = tf.trainable_variables()
if variable_filter_fn:
var_list = variable_filter_fn(var_list)
if params.get('clip_gradients_norm', None):
logging.info('clip gradients norm by %f', params['clip_gradients_norm'])
grads_and_vars = optimizer.compute_gradients(total_loss, var_list)
with tf.name_scope('clip'):
grads = [gv[0] for gv in grads_and_vars]
tvars = [gv[1] for gv in grads_and_vars]
# First clip each variable's norm, then clip global norm.
clip_norm = abs(params['clip_gradients_norm'])
clipped_grads = [
tf.clip_by_norm(g, clip_norm) if g is not None else None
for g in grads
]
clipped_grads, _ = tf.clip_by_global_norm(clipped_grads, clip_norm)
utils.scalar('gradient_norm', tf.linalg.global_norm(clipped_grads),
is_tpu)
grads_and_vars = list(zip(clipped_grads, tvars))
with tf.control_dependencies(update_ops):
train_op = optimizer.apply_gradients(grads_and_vars, global_step)
else:
with tf.control_dependencies(update_ops):
train_op = optimizer.minimize(
total_loss, global_step, var_list=var_list)
if moving_average_decay:
with tf.control_dependencies([train_op]):
train_op = ema.apply(ema_vars)
else:
train_op = None
eval_metrics = None
if mode == tf.estimator.ModeKeys.EVAL:
def metric_fn(**kwargs):
"""Returns a dictionary that has the evaluation metrics."""
if params['nms_configs'].get('pyfunc', True):
detections_bs = []
nms_configs = params['nms_configs']
for index in range(kwargs['boxes'].shape[0]):
detections = tf.numpy_function(
functools.partial(nms_np.per_class_nms, nms_configs=nms_configs),
[
kwargs['boxes'][index],
kwargs['scores'][index],
kwargs['classes'][index],
tf.slice(kwargs['image_ids'], [index], [1]),
tf.slice(kwargs['image_scales'], [index], [1]),
params['num_classes'],
nms_configs['max_output_size'],
], tf.float32)
detections_bs.append(detections)
detections_bs = postprocess.transform_detections(
tf.stack(detections_bs))
else:
# These two branches should be equivalent, but currently they are not.
# TODO(tanmingxing): enable the non_pyfun path after bug fix.
nms_boxes, nms_scores, nms_classes, _ = postprocess.per_class_nms(
params, kwargs['boxes'], kwargs['scores'], kwargs['classes'],
kwargs['image_scales'])
img_ids = tf.cast(
tf.expand_dims(kwargs['image_ids'], -1), nms_scores.dtype)
detections_bs = [
img_ids * tf.ones_like(nms_scores),
nms_boxes[:, :, 1],
nms_boxes[:, :, 0],
nms_boxes[:, :, 3] - nms_boxes[:, :, 1],
nms_boxes[:, :, 2] - nms_boxes[:, :, 0],
nms_scores,
nms_classes,
]
detections_bs = tf.stack(detections_bs, axis=-1, name='detnections')
if params.get('testdev_dir', None):
logging.info('Eval testdev_dir %s', params['testdev_dir'])
eval_metric = coco_metric.EvaluationMetric(
testdev_dir=params['testdev_dir'])
coco_metrics = eval_metric.estimator_metric_fn(detections_bs,
tf.zeros([1]))
else:
logging.info('Eval val with groudtruths %s.', params['val_json_file'])
eval_metric = coco_metric.EvaluationMetric(
filename=params['val_json_file'], label_map=params['label_map'])
coco_metrics = eval_metric.estimator_metric_fn(
detections_bs, kwargs['groundtruth_data'])
# Add metrics to output.
cls_loss = tf.metrics.mean(kwargs['cls_loss_repeat'])
box_loss = tf.metrics.mean(kwargs['box_loss_repeat'])
output_metrics = {
'cls_loss': cls_loss,
'box_loss': box_loss,
}
output_metrics.update(coco_metrics)
return output_metrics
cls_loss_repeat = tf.reshape(
tf.tile(tf.expand_dims(cls_loss, 0), [
params['batch_size'],
]), [params['batch_size'], 1])
box_loss_repeat = tf.reshape(
tf.tile(tf.expand_dims(box_loss, 0), [
params['batch_size'],
]), [params['batch_size'], 1])
cls_outputs = postprocess.to_list(cls_outputs)
box_outputs = postprocess.to_list(box_outputs)
params['nms_configs']['max_nms_inputs'] = anchors.MAX_DETECTION_POINTS
boxes, scores, classes = postprocess.pre_nms(params, cls_outputs,
box_outputs)
metric_fn_inputs = {
'cls_loss_repeat': cls_loss_repeat,
'box_loss_repeat': box_loss_repeat,
'image_ids': labels['source_ids'],
'groundtruth_data': labels['groundtruth_data'],
'image_scales': labels['image_scales'],
'boxes': boxes,
'scores': scores,
'classes': classes,
}
eval_metrics = (metric_fn, metric_fn_inputs)
checkpoint = params.get('ckpt') or params.get('backbone_ckpt')
if checkpoint and mode == tf.estimator.ModeKeys.TRAIN:
# Initialize the model from an EfficientDet or backbone checkpoint.
if params.get('ckpt') and params.get('backbone_ckpt'):
raise RuntimeError(
'--backbone_ckpt and --checkpoint are mutually exclusive')
if params.get('backbone_ckpt'):
var_scope = params['backbone_name'] + '/'
if params['ckpt_var_scope'] is None:
# Use backbone name as default checkpoint scope.
ckpt_scope = params['backbone_name'] + '/'
else:
ckpt_scope = params['ckpt_var_scope'] + '/'
else:
# Load every var in the given checkpoint
var_scope = ckpt_scope = '/'
def scaffold_fn():
"""Loads pretrained model through scaffold function."""
logging.info('restore variables from %s', checkpoint)
var_map = utils.get_ckpt_var_map(
ckpt_path=checkpoint,
ckpt_scope=ckpt_scope,
var_scope=var_scope,
skip_mismatch=params['skip_mismatch'])
tf.train.init_from_checkpoint(checkpoint, var_map)
return tf.train.Scaffold()
elif mode == tf.estimator.ModeKeys.EVAL and moving_average_decay:
def scaffold_fn():
"""Load moving average variables for eval."""
logging.info('Load EMA vars with ema_decay=%f', moving_average_decay)
restore_vars_dict = ema.variables_to_restore(ema_vars)
saver = tf.train.Saver(restore_vars_dict)
return tf.train.Scaffold(saver=saver)
else:
scaffold_fn = None
if is_tpu:
return tf.estimator.tpu.TPUEstimatorSpec(
mode=mode,
loss=total_loss,
train_op=train_op,
eval_metrics=eval_metrics,
host_call=utils.get_tpu_host_call(global_step, params),
scaffold_fn=scaffold_fn,
training_hooks=training_hooks)
else:
# Profile every 1K steps.
if params.get('profile', False):
profile_hook = tf.estimator.ProfilerHook(
save_steps=1000, output_dir=params['model_dir'], show_memory=True)
training_hooks.append(profile_hook)
# Report memory allocation if OOM; it will slow down the running.
class OomReportingHook(tf.estimator.SessionRunHook):
def before_run(self, run_context):
return tf.estimator.SessionRunArgs(
fetches=[],
options=tf.RunOptions(report_tensor_allocations_upon_oom=True))
training_hooks.append(OomReportingHook())
logging_hook = tf.estimator.LoggingTensorHook(
{
'step': global_step,
'det_loss': det_loss,
'cls_loss': cls_loss,
'box_loss': box_loss,
},
every_n_iter=params.get('iterations_per_loop', 100),
)
training_hooks.append(logging_hook)
eval_metric_ops = (
eval_metrics[0](**eval_metrics[1]) if eval_metrics else None)
return tf.estimator.EstimatorSpec(
mode=mode,
loss=total_loss,
train_op=train_op,
eval_metric_ops=eval_metric_ops,
scaffold=scaffold_fn() if scaffold_fn else None,
training_hooks=training_hooks)