def __init__(
self,
checkpoint=None,
text_postproc=None,
data_preproc=None,
codec=None,
network=None,
batch_size=1,
processes=1,
auto_update_checkpoints=True,
with_gt=False,
ctc_decoder_params=None,
):
""" Predicting a dataset based on a trained model
Parameters
----------
checkpoint : str, optional
filepath of the checkpoint of the network to load, alternatively you can directly use a loaded `network`
text_postproc : TextProcessor, optional
text processor to be applied on the predicted sentence for the final output.
If loaded from a checkpoint the text processor will be loaded from it.
data_preproc : DataProcessor, optional
data processor (must be the same as of the trained model) to be applied to the input image.
If loaded from a checkpoint the text processor will be loaded from it.
codec : Codec, optional
Codec of the deep net to use for decoding. This parameter is only required if a custom codec is used,
or a `network` has been provided instead of a `checkpoint`
network : ModelInterface, optional
DNN instance to used. Alternatively you can provide a `checkpoint` to load a network.
batch_size : int, optional
Batch size to use for prediction
processes : int, optional
The number of processes to use for prediction
auto_update_checkpoints : bool, optional
Update old models automatically (this will change the checkpoint files)
with_gt : bool, optional
The prediction will also output the ground truth if available else None
ctc_decoder_params : optional
Parameters of the ctc decoder
"""
self.network = network
self.checkpoint = checkpoint
self.processes = processes
self.auto_update_checkpoints = auto_update_checkpoints
self.with_gt = with_gt
if checkpoint:
if network:
raise Exception(
"Either a checkpoint or a network can be provided")
ckpt = Checkpoint(checkpoint,
auto_update=self.auto_update_checkpoints)
self.checkpoint = ckpt.ckpt_path
checkpoint_params = ckpt.checkpoint
self.model_params = checkpoint_params.model
self.codec = codec if codec else Codec(
self.model_params.codec.charset)
self.network_params = self.model_params.network
backend = create_backend_from_checkpoint(
checkpoint_params=checkpoint_params, processes=processes)
self.text_postproc = text_postproc if text_postproc else text_processor_from_proto(
self.model_params.text_postprocessor, "post")
self.data_preproc = data_preproc if data_preproc else data_processor_from_proto(
self.model_params.data_preprocessor)
self.network = backend.create_net(
codec=self.codec,
ctc_decoder_params=ctc_decoder_params,
checkpoint_to_load=ckpt,
graph_type="predict",
batch_size=batch_size)
elif network:
self.codec = codec
self.model_params = None
self.network_params = network.network_proto
self.text_postproc = text_postproc
self.data_preproc = data_preproc
if not codec:
raise Exception(
"A codec is required if preloaded network is used.")
else:
raise Exception(
"Either a checkpoint or a existing backend must be provided")
self.out_to_in_trans = OutputToInputTransformer(
self.data_preproc, self.network)
def train(self, auto_compute_codec=False, progress_bar=False, training_callback=ConsoleTrainingCallback()):
""" Launch the training
Parameters
----------
auto_compute_codec : bool
Compute the codec automatically based on the provided ground truth.
Else provide a codec using a whitelist (faster).
progress_bar : bool
Show or hide any progress bar
training_callback : TrainingCallback
Callback for the training process (e.g., for displaying the current cer, loss in the console)
"""
with ExitStackWithPop() as exit_stack:
checkpoint_params = self.checkpoint_params
train_start_time = time.time() + self.checkpoint_params.total_time
exit_stack.enter_context(self.dataset)
if self.validation_dataset:
exit_stack.enter_context(self.validation_dataset)
# load training dataset
if self.preload_training:
new_dataset = self.dataset.to_raw_input_dataset(processes=checkpoint_params.processes, progress_bar=progress_bar)
exit_stack.pop(self.dataset)
self.dataset = new_dataset
exit_stack.enter_context(self.dataset)
# load validation dataset
if self.validation_dataset and self.preload_validation:
new_dataset = self.validation_dataset.to_raw_input_dataset(processes=checkpoint_params.processes, progress_bar=progress_bar)
exit_stack.pop(self.validation_dataset)
self.validation_dataset = new_dataset
exit_stack.enter_context(self.validation_dataset)
# compute the codec
if self.codec:
codec = self.codec
else:
if len(self.codec_whitelist) == 0 or auto_compute_codec:
codec = Codec.from_input_dataset([self.dataset, self.validation_dataset],
whitelist=self.codec_whitelist, progress_bar=progress_bar)
else:
codec = Codec.from_texts([], whitelist=self.codec_whitelist)
# create backend
network_params = checkpoint_params.model.network
network_params.features = checkpoint_params.model.line_height
if self.weights:
# if we load the weights, take care of codec changes as-well
ckpt = Checkpoint(self.weights + '.json', auto_update=self.auto_update_checkpoints)
restore_checkpoint_params = ckpt.checkpoint
restore_model_params = restore_checkpoint_params.model
# checks
if checkpoint_params.model.line_height != network_params.features:
raise Exception("The model to restore has a line height of {} but a line height of {} is requested".format(
network_params.features, checkpoint_params.model.line_height
))
# create codec of the same type
restore_codec = codec.__class__(restore_model_params.codec.charset)
# the codec changes as tuple (deletions/insertions), and the new codec is the changed old one
codec_changes = restore_codec.align(codec, shrink=not self.keep_loaded_codec)
codec = restore_codec
print("Codec changes: {} deletions, {} appends".format(len(codec_changes[0]), len(codec_changes[1])))
# The actual weight/bias matrix will be changed after loading the old weights
if all([c == 0 for c in codec_changes]):
codec_changes = None # No codec changes
else:
codec_changes = None
# store the new codec
network_params.classes = len(codec)
checkpoint_params.model.codec.charset[:] = codec.charset
print("CODEC: {}".format(codec.charset))
backend = create_backend_from_checkpoint(
checkpoint_params=checkpoint_params,
processes=checkpoint_params.processes,
)
train_net = backend.create_net(codec, graph_type="train",
checkpoint_to_load=Checkpoint(self.weights) if self.weights else None,
batch_size=checkpoint_params.batch_size, codec_changes=codec_changes)
if checkpoint_params.current_stage == 0:
self._run_train(train_net, train_start_time, progress_bar, self.dataset, self.validation_dataset, training_callback)
if checkpoint_params.data_aug_retrain_on_original and self.data_augmenter and self.n_augmentations != 0:
print("Starting training on original data only")
if checkpoint_params.current_stage == 0:
checkpoint_params.current_stage = 1
checkpoint_params.iter = 0
checkpoint_params.early_stopping_best_at_iter = 0
checkpoint_params.early_stopping_best_cur_nbest = 0
checkpoint_params.early_stopping_best_accuracy = 0
self.dataset.generate_only_non_augmented = True # this is the important line!
self._run_train(train_net, train_start_time, progress_bar, self.dataset, self.validation_dataset, training_callback)