Source code for detectron2.export.api

# Copyright (c) Facebook, Inc. and its affiliates.
import copy
import logging
import os
import torch
from caffe2.proto import caffe2_pb2
from torch import nn

from detectron2.config import CfgNode
from detectron2.utils.file_io import PathManager

from .caffe2_inference import ProtobufDetectionModel
from .caffe2_modeling import META_ARCH_CAFFE2_EXPORT_TYPE_MAP, convert_batched_inputs_to_c2_format
from .shared import get_pb_arg_vali, get_pb_arg_vals, save_graph

__all__ = [

[docs]def add_export_config(cfg): """ Add options needed by caffe2 export. Args: cfg (CfgNode): a detectron2 config Returns: CfgNode: an updated config with new options that will be used by :class:`Caffe2Tracer`. """ is_frozen = cfg.is_frozen() cfg.defrost() cfg.EXPORT_CAFFE2 = CfgNode() cfg.EXPORT_CAFFE2.USE_HEATMAP_MAX_KEYPOINT = False if is_frozen: cfg.freeze() return cfg
[docs]class Caffe2Tracer: """ Make a detectron2 model traceable with Caffe2 operators. This class creates a traceable version of a detectron2 model which: 1. Rewrite parts of the model using ops in Caffe2. Note that some ops do not have GPU implementation in Caffe2. 2. Remove post-processing and only produce raw layer outputs After making a traceable model, the class provide methods to export such a model to different deployment formats. Exported graph produced by this class take two input tensors: 1. (1, C, H, W) float "data" which is an image (usually in [0, 255]). (H, W) often has to be padded to multiple of 32 (depend on the model architecture). 2. 1x3 float "im_info", each row of which is (height, width, 1.0). Height and width are true image shapes before padding. The class currently only supports models using builtin meta architectures. Batch inference is not supported, and contributions are welcome. """
[docs] def __init__(self, cfg: CfgNode, model: nn.Module, inputs): """ Args: cfg (CfgNode): a detectron2 config, with extra export-related options added by :func:`add_export_config`. It's used to construct caffe2-compatible model. model (nn.Module): An original pytorch model. Must be among a few official models in detectron2 that can be converted to become caffe2-compatible automatically. Weights have to be already loaded to this model. inputs: sample inputs that the given model takes for inference. Will be used to trace the model. For most models, random inputs with no detected objects will not work as they lead to wrong traces. """ assert isinstance(cfg, CfgNode), cfg assert isinstance(model, torch.nn.Module), type(model) if "EXPORT_CAFFE2" not in cfg: cfg = add_export_config(cfg) # will just the defaults # TODO make it support custom models, by passing in c2 model directly C2MetaArch = META_ARCH_CAFFE2_EXPORT_TYPE_MAP[cfg.MODEL.META_ARCHITECTURE] self.traceable_model = C2MetaArch(cfg, copy.deepcopy(model)) self.inputs = inputs self.traceable_inputs = self.traceable_model.get_caffe2_inputs(inputs)
[docs] def export_caffe2(self): """ Export the model to Caffe2's protobuf format. The returned object can be saved with its :meth:`.save_protobuf()` method. The result can be loaded and executed using Caffe2 runtime. Returns: :class:`Caffe2Model` """ from .caffe2_export import export_caffe2_detection_model predict_net, init_net = export_caffe2_detection_model( self.traceable_model, self.traceable_inputs ) return Caffe2Model(predict_net, init_net)
[docs] def export_onnx(self): """ Export the model to ONNX format. Note that the exported model contains custom ops only available in caffe2, therefore it cannot be directly executed by other runtime (such as onnxruntime or TensorRT). Post-processing or transformation passes may be applied on the model to accommodate different runtimes, but we currently do not provide support for them. Returns: onnx.ModelProto: an onnx model. """ from .caffe2_export import export_onnx_model as export_onnx_model_impl return export_onnx_model_impl(self.traceable_model, (self.traceable_inputs,))
[docs] def export_torchscript(self): """ Export the model to a ``torch.jit.TracedModule`` by tracing. The returned object can be saved to a file by ``.save()``. Returns: torch.jit.TracedModule: a torch TracedModule """ logger = logging.getLogger(__name__)"Tracing the model with torch.jit.trace ...") with torch.no_grad(): return torch.jit.trace(self.traceable_model, (self.traceable_inputs,))
[docs]class Caffe2Model(nn.Module): """ A wrapper around the traced model in Caffe2's protobuf format. The exported graph has different inputs/outputs from the original Pytorch model, as explained in :class:`Caffe2Tracer`. This class wraps around the exported graph to simulate the same interface as the original Pytorch model. It also provides functions to save/load models in Caffe2's format.' Examples: :: c2_model = Caffe2Tracer(cfg, torch_model, inputs).export_caffe2() inputs = [{"image": img_tensor_CHW}] outputs = c2_model(inputs) orig_outputs = torch_model(inputs) """ def __init__(self, predict_net, init_net): super().__init__() self.eval() # always in eval mode self._predict_net = predict_net self._init_net = init_net self._predictor = None __init__.__HIDE_SPHINX_DOC__ = True @property def predict_net(self): """ caffe2.core.Net: the underlying caffe2 predict net """ return self._predict_net @property def init_net(self): """ caffe2.core.Net: the underlying caffe2 init net """ return self._init_net
[docs] def save_protobuf(self, output_dir): """ Save the model as caffe2's protobuf format. It saves the following files: * "model.pb": definition of the graph. Can be visualized with tools like `netron <>`_. * "model_init.pb": model parameters * "model.pbtxt": human-readable definition of the graph. Not needed for deployment. Args: output_dir (str): the output directory to save protobuf files. """ logger = logging.getLogger(__name__)"Saving model to {} ...".format(output_dir)) if not PathManager.exists(output_dir): PathManager.mkdirs(output_dir) with, "model.pb"), "wb") as f: f.write(self._predict_net.SerializeToString()) with, "model.pbtxt"), "w") as f: f.write(str(self._predict_net)) with, "model_init.pb"), "wb") as f: f.write(self._init_net.SerializeToString())
[docs] def save_graph(self, output_file, inputs=None): """ Save the graph as SVG format. Args: output_file (str): a SVG file inputs: optional inputs given to the model. If given, the inputs will be used to run the graph to record shape of every tensor. The shape information will be saved together with the graph. """ from .caffe2_export import run_and_save_graph if inputs is None: save_graph(self._predict_net, output_file, op_only=False) else: size_divisibility = get_pb_arg_vali(self._predict_net, "size_divisibility", 0) device = get_pb_arg_vals(self._predict_net, "device", b"cpu").decode("ascii") inputs = convert_batched_inputs_to_c2_format(inputs, size_divisibility, device) inputs = [x.cpu().numpy() for x in inputs] run_and_save_graph(self._predict_net, self._init_net, inputs, output_file)
[docs] @staticmethod def load_protobuf(dir): """ Args: dir (str): a directory used to save Caffe2Model with :meth:`save_protobuf`. The files "model.pb" and "model_init.pb" are needed. Returns: Caffe2Model: the caffe2 model loaded from this directory. """ predict_net = caffe2_pb2.NetDef() with, "model.pb"), "rb") as f: predict_net.ParseFromString( init_net = caffe2_pb2.NetDef() with, "model_init.pb"), "rb") as f: init_net.ParseFromString( return Caffe2Model(predict_net, init_net)
[docs] def __call__(self, inputs): """ An interface that wraps around a Caffe2 model and mimics detectron2's models' input/output format. See details about the format at :doc:`/tutorials/models`. This is used to compare the outputs of caffe2 model with its original torch model. Due to the extra conversion between Pytorch/Caffe2, this method is not meant for benchmark. Because of the conversion, this method also has dependency on detectron2 in order to convert to detectron2's output format. """ if self._predictor is None: self._predictor = ProtobufDetectionModel(self._predict_net, self._init_net) return self._predictor(inputs)
def export_caffe2_model(cfg, model, inputs): logger = logging.getLogger(__name__) logger.warning( "export_caffe2_model() is deprecated. Please use `Caffe2Tracer().export_caffe2() instead." ) return Caffe2Tracer(cfg, model, inputs).export_caffe2() def export_onnx_model(cfg, model, inputs): logger = logging.getLogger(__name__) logger.warning( "export_caffe2_model() is deprecated. Please use `Caffe2Tracer().export_onnx() instead." ) return Caffe2Tracer(cfg, model, inputs).export_onnx()