# Copyright 2017 The TensorFlow Authors. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # ============================================================================== """TensorFlow Lite tooling helper functionality. EXPERIMENTAL: APIs here are unstable and likely to change without notice. @@TocoConverter @@toco_convert @@toco_convert_protos @@Interpreter @@OpHint @@convert_op_hints_to_stubs @@build_toco_convert_protos @@FLOAT @@QUANTIZED_UINT8 @@TFLITE @@GRAPHVIZ_DOT """ from __future__ import absolute_import from __future__ import division from __future__ import print_function from six import PY3 from google.protobuf import text_format as _text_format from google.protobuf.message import DecodeError from tensorflow.contrib.lite.python import lite_constants as constants from tensorflow.contrib.lite.python.convert import build_toco_convert_protos # pylint: disable=unused-import from tensorflow.contrib.lite.python.convert import tensor_name as _tensor_name from tensorflow.contrib.lite.python.convert import toco_convert from tensorflow.contrib.lite.python.convert import toco_convert_protos # pylint: disable=unused-import from tensorflow.contrib.lite.python.convert_saved_model import freeze_saved_model as _freeze_saved_model from tensorflow.contrib.lite.python.convert_saved_model import get_tensors_from_tensor_names as _get_tensors_from_tensor_names from tensorflow.contrib.lite.python.convert_saved_model import set_tensor_shapes as _set_tensor_shapes from tensorflow.contrib.lite.python.interpreter import Interpreter # pylint: disable=unused-import from tensorflow.contrib.lite.python.op_hint import convert_op_hints_to_stubs # pylint: disable=unused-import from tensorflow.contrib.lite.python.op_hint import OpHint # pylint: disable=unused-import from tensorflow.core.framework import graph_pb2 as _graph_pb2 from tensorflow.python import keras as _keras from tensorflow.python.client import session as _session from tensorflow.python.framework import graph_util as _tf_graph_util from tensorflow.python.framework.importer import import_graph_def as _import_graph_def from tensorflow.python.ops.variables import global_variables_initializer as _global_variables_initializer from tensorflow.python.saved_model import signature_constants as _signature_constants from tensorflow.python.saved_model import tag_constants as _tag_constants class TocoConverter(object): """Convert a TensorFlow model into `output_format` using TOCO. This is used to convert from a TensorFlow GraphDef or SavedModel into either a TFLite FlatBuffer or graph visualization. Attributes: inference_type: Target data type of real-number arrays in the output file. Must be `{FLOAT, QUANTIZED_UINT8}`. (default FLOAT) inference_input_type: Target data type of real-number input arrays. Allows for a different type for input arrays in the case of quantization. Must be `{FLOAT, QUANTIZED_UINT8}`. (default `inference_type`) output_format: Output file format. Currently must be `{TFLITE, GRAPHVIZ_DOT}`. (default TFLITE) quantized_input_stats: Dict of strings representing input tensor names mapped to tuple of integers representing the mean and standard deviation of the training data (e.g., {"foo" : (0., 1.)}). Only need if `inference_type` is `QUANTIZED_UINT8`. (default {}) default_ranges_stats: Tuple of integers representing (min, max) range values for all arrays without a specified range. Intended for experimenting with quantization via "dummy quantization". (default None) drop_control_dependency: Boolean indicating whether to drop control dependencies silently. This is due to TFLite not supporting control dependencies. (default True) reorder_across_fake_quant: Boolean indicating whether to reorder FakeQuant nodes in unexpected locations. Used when the location of the FakeQuant nodes is preventing graph transformations necessary to convert the graph. Results in a graph that differs from the quantized training graph, potentially causing differing arithmetic behavior. (default False) change_concat_input_ranges: Boolean to change behavior of min/max ranges for inputs and outputs of the concat operator for quantized models. Changes the ranges of concat operator overlap when true. (default False) allow_custom_ops: Boolean indicating whether to allow custom operations. When false any unknown operation is an error. When true, custom ops are created for any op that is unknown. The developer will need to provide these to the TensorFlow Lite runtime with a custom resolver. (default False) quantize_weights: Boolean indicating whether to store weights as quantized weights followed by dequantize operations. Computation is still done in float, but reduces model size (at the cost of accuracy and latency). (default False) dump_graphviz_dir: Full filepath of folder to dump the graphs at various stages of processing GraphViz .dot files. Preferred over --output_format=GRAPHVIZ_DOT in order to keep the requirements of the output file. (default None) dump_graphviz_video: Boolean indicating whether to dump the graph after every graph transformation. (default False) Example usage: # Converting a GraphDef from session. converter = lite.TocoConverter.from_session(sess, in_tensors, out_tensors) tflite_model = converter.convert() open("converted_model.tflite", "wb").write(tflite_model) # Converting a GraphDef from file. converter = lite.TocoConverter.from_frozen_graph( graph_def_file, input_arrays, output_arrays) tflite_model = converter.convert() open("converted_model.tflite", "wb").write(tflite_model) # Converting a SavedModel. converter = lite.TocoConverter.from_saved_model(saved_model_dir) tflite_model = converter.convert() """ def __init__(self, graph_def, input_tensors, output_tensors): """Constructor for TocoConverter. Args: graph_def: Frozen TensorFlow GraphDef. input_tensors: List of input tensors. Type and shape are computed using `foo.get_shape()` and `foo.dtype`. output_tensors: List of output tensors (only .name is used from this). """ self._graph_def = graph_def self._input_tensors = input_tensors self._output_tensors = output_tensors self.inference_type = constants.FLOAT self.inference_input_type = None self.output_format = constants.TFLITE self.quantized_input_stats = {} self.default_ranges_stats = None self.drop_control_dependency = True self.reorder_across_fake_quant = False self.change_concat_input_ranges = False self.allow_custom_ops = False self.quantize_weights = False self.dump_graphviz_dir = None self.dump_graphviz_video = False @classmethod def from_session(cls, sess, input_tensors, output_tensors): """Creates a TocoConverter class from a TensorFlow Session. Args: sess: TensorFlow Session. input_tensors: List of input tensors. Type and shape are computed using `foo.get_shape()` and `foo.dtype`. output_tensors: List of output tensors (only .name is used from this). Returns: TocoConverter class. """ graph_def = _freeze_graph(sess, output_tensors) return cls(graph_def, input_tensors, output_tensors) @classmethod def from_frozen_graph(cls, graph_def_file, input_arrays, output_arrays, input_shapes=None): """Creates a TocoConverter class from a file containing a frozen GraphDef. Args: graph_def_file: Full filepath of file containing frozen GraphDef. input_arrays: List of input tensors to freeze graph with. output_arrays: List of output tensors to freeze graph with. input_shapes: Dict of strings representing input tensor names to list of integers representing input shapes (e.g., {"foo" : [1, 16, 16, 3]}). Automatically determined when input shapes is None (e.g., {"foo" : None}). (default None) Returns: TocoConverter class. Raises: ValueError: Unable to parse input file. The graph is not frozen. input_arrays or output_arrays contains an invalid tensor name. """ with _session.Session() as sess: sess.run(_global_variables_initializer()) # Read GraphDef from file. graph_def = _graph_pb2.GraphDef() with open(graph_def_file, "rb") as f: file_content = f.read() try: graph_def.ParseFromString(file_content) except (_text_format.ParseError, DecodeError): try: print("Ignore 'tcmalloc: large alloc' warnings.") if not isinstance(file_content, str): if PY3: file_content = file_content.decode('utf-8') else: file_content = file_content.encode('utf-8') _text_format.Merge(file_content, graph_def) except (_text_format.ParseError, DecodeError): raise ValueError( "Unable to parse input file '{}'.".format(graph_def_file)) sess.graph.as_default() _import_graph_def(graph_def, name="") # Get input and output tensors. input_tensors = _get_tensors_from_tensor_names(sess.graph, input_arrays) output_tensors = _get_tensors_from_tensor_names(sess.graph, output_arrays) _set_tensor_shapes(input_tensors, input_shapes) # Check if graph is frozen. if not _is_frozen_graph(sess): raise ValueError("Please freeze the graph using freeze_graph.py.") # Create TocoConverter class. return cls(sess.graph_def, input_tensors, output_tensors) @classmethod def from_saved_model(cls, saved_model_dir, input_arrays=None, input_shapes=None, output_arrays=None, tag_set=None, signature_key=None): """Creates a TocoConverter class from a SavedModel. Args: saved_model_dir: SavedModel directory to convert. input_arrays: List of input tensors to freeze graph with. Uses input arrays from SignatureDef when none are provided. (default None) input_shapes: Dict of strings representing input tensor names to list of integers representing input shapes (e.g., {"foo" : [1, 16, 16, 3]}). Automatically determined when input shapes is None (e.g., {"foo" : None}). (default None) output_arrays: List of output tensors to freeze graph with. Uses output arrays from SignatureDef when none are provided. (default None) tag_set: Set of tags identifying the MetaGraphDef within the SavedModel to analyze. All tags in the tag set must be present. (default set("serve")) signature_key: Key identifying SignatureDef containing inputs and outputs. (default DEFAULT_SERVING_SIGNATURE_DEF_KEY) Returns: TocoConverter class. """ if tag_set is None: tag_set = set([_tag_constants.SERVING]) if signature_key is None: signature_key = _signature_constants.DEFAULT_SERVING_SIGNATURE_DEF_KEY result = _freeze_saved_model(saved_model_dir, input_arrays, input_shapes, output_arrays, tag_set, signature_key) return cls( graph_def=result[0], input_tensors=result[1], output_tensors=result[2]) @classmethod def from_keras_model_file(cls, model_file, input_arrays=None, input_shapes=None, output_arrays=None): """Creates a TocoConverter class from a tf.keras model file. Args: model_file: Full filepath of HDF5 file containing the tf.keras model. input_arrays: List of input tensors to freeze graph with. Uses input arrays from SignatureDef when none are provided. (default None) input_shapes: Dict of strings representing input tensor names to list of integers representing input shapes (e.g., {"foo" : [1, 16, 16, 3]}). Automatically determined when input shapes is None (e.g., {"foo" : None}). (default None) output_arrays: List of output tensors to freeze graph with. Uses output arrays from SignatureDef when none are provided. (default None) Returns: TocoConverter class. """ _keras.backend.clear_session() _keras.backend.set_learning_phase(False) keras_model = _keras.models.load_model(model_file) sess = _keras.backend.get_session() # Get input and output tensors. if input_arrays: input_tensors = _get_tensors_from_tensor_names(sess.graph, input_arrays) else: input_tensors = keras_model.inputs if output_arrays: output_tensors = _get_tensors_from_tensor_names(sess.graph, output_arrays) else: output_tensors = keras_model.outputs _set_tensor_shapes(input_tensors, input_shapes) graph_def = _freeze_graph(sess, output_tensors) return cls(graph_def, input_tensors, output_tensors) def convert(self): """Converts a TensorFlow GraphDef based on instance variables. Returns: The converted data in serialized format. Either a TFLite Flatbuffer or a Graphviz graph depending on value in `output_format`. Raises: ValueError: Input shape is not specified. None value for dimension in input_tensor. """ # Checks dimensions in input tensor. for tensor in self._input_tensors: if not tensor.get_shape(): raise ValueError("Provide an input shape for input array '{0}'.".format( _tensor_name(tensor))) shape = tensor.get_shape().as_list() if None in shape[1:]: raise ValueError( "None is only supported in the 1st dimension. Tensor '{0}' has " "invalid shape '{1}'.".format(_tensor_name(tensor), shape)) elif shape[0] is None: self._set_batch_size(batch_size=1) # Get quantization stats. Ensures there is one stat per name if the stats # are specified. if self.quantized_input_stats: quantized_stats = [] invalid_stats = [] for tensor in self._input_tensors: name = _tensor_name(tensor) if name in self.quantized_input_stats: quantized_stats.append(self.quantized_input_stats[name]) else: invalid_stats.append(name) if invalid_stats: raise ValueError("Quantization input stats are not available for input " "tensors '{0}'.".format(",".join(invalid_stats))) else: quantized_stats = None # Converts model. result = toco_convert( input_data=self._graph_def, input_tensors=self._input_tensors, output_tensors=self._output_tensors, inference_type=self.inference_type, inference_input_type=self.inference_input_type, input_format=constants.TENSORFLOW_GRAPHDEF, output_format=self.output_format, quantized_input_stats=quantized_stats, default_ranges_stats=self.default_ranges_stats, drop_control_dependency=self.drop_control_dependency, reorder_across_fake_quant=self.reorder_across_fake_quant, change_concat_input_ranges=self.change_concat_input_ranges, allow_custom_ops=self.allow_custom_ops, quantize_weights=self.quantize_weights, dump_graphviz_dir=self.dump_graphviz_dir, dump_graphviz_video=self.dump_graphviz_video) return result def get_input_arrays(self): """Returns a list of the names of the input tensors. Returns: List of strings. """ return [_tensor_name(tensor) for tensor in self._input_tensors] def _set_batch_size(self, batch_size): """Sets the first dimension of the input tensor to `batch_size`. Args: batch_size: Batch size for the model. Replaces the first dimension of an input size array if undefined. (default 1) """ for tensor in self._input_tensors: shape = tensor.get_shape().as_list() shape[0] = batch_size tensor.set_shape(shape) def _is_frozen_graph(sess): """Determines if the graph is frozen. Determines if a graph has previously been frozen by checking for any operations of type Variable*. If variables are found, the graph is not frozen. Args: sess: TensorFlow Session. Returns: Bool. """ for op in sess.graph.get_operations(): if op.type.startswith("Variable") or op.type.endswith("VariableOp"): return False return True def _freeze_graph(sess, output_tensors): """Returns a frozen GraphDef. Freezes a graph with Variables in it. Otherwise the existing GraphDef is returned. Args: sess: TensorFlow Session. output_tensors: List of output tensors (only .name is used from this). Returns: Frozen GraphDef. """ if not _is_frozen_graph(sess): sess.run(_global_variables_initializer()) output_arrays = [_tensor_name(tensor) for tensor in output_tensors] return _tf_graph_util.convert_variables_to_constants( sess, sess.graph_def, output_arrays) else: return sess.graph_def