[MXNET-533] MXNet-ONNX export

LICENSE

@@ -298,8 +298,6 @@
     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
-
     =======================================================================================
     Other Licenses
     =======================================================================================
@@ -512,3 +510,53 @@
     For details, see, 3rdparty/dmlc-core/include/dmlc/concurrentqueue.h
 
     =======================================================================================
+
+    11. ONNX Export module
+    For details, see, python/mxnet/contrib/onnx/_export/LICENSE
+
+    # Licensed to the Apache Software Foundation (ASF) under one
+    # or more contributor license agreements.  See the NOTICE file
+    # distributed with this work for additional information
+    # regarding copyright ownership.  The ASF licenses this file
+    # to you 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.
+    #
+    # Based on
+    # https://github.com/NVIDIA/mxnet_to_onnx/blob/master/mx2onnx_converter/#
+    #  Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
+    #
+    #  Redistribution and use in source and binary forms, with or without
+    #  modification, are permitted provided that the following conditions
+    #  are met:
+    #  * Redistributions of source code must retain the above copyright
+    #    notice, this list of conditions and the following disclaimer.
+    #  * Redistributions in binary form must reproduce the above copyright
+    #    notice, this list of conditions and the following disclaimer in the
+    #    documentation and/or other materials provided with the distribution.
+    #  * Neither the name of NVIDIA CORPORATION nor the names of its
+    #    contributors may be used to endorse or promote products derived
+    #    from this software without specific prior written permission.
+    #
+    #  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+    #  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    #  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+    #  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+    #  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+    #  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+    #  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+    #  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+    #  OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    #  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+    #  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+

ci/docker/runtime_functions.sh

@@ -601,6 +601,8 @@ integrationtest_ubuntu_cpu_onnx() {
 	pytest tests/python-pytest/onnx/import/mxnet_backend_test.py
 	pytest tests/python-pytest/onnx/import/onnx_import_test.py
 	pytest tests/python-pytest/onnx/import/gluon_backend_test.py
+	pytest tests/python-pytest/onnx/export/onnx_backend_test.py
+	python tests/python-pytest/onnx/export/mxnet_export_test.py
 }
 
 integrationtest_ubuntu_gpu_python() {

docs/api/python/contrib/onnx.md

@@ -24,6 +24,7 @@ This document describes all the ONNX-MXNet APIs.
 
     mxnet.contrib.onnx.import_model
     mxnet.contrib.onnx.get_model_metadata
+    mxnet.contrib.onnx.export_model
 ```
 
 ## ONNX Tutorials
@@ -46,6 +47,7 @@ This document describes all the ONNX-MXNet APIs.
 .. automodule:: mxnet.contrib.onnx
     :members: import_model
     :members: get_model_metadata
+    :members: export_model
 
 ```
 

python/mxnet/contrib/onnx/__init__.py

@@ -16,5 +16,6 @@
 # under the License.
 """Module for ONNX model format support for Apache MXNet."""
 
-from ._import.import_model import import_model, get_model_metadata
-from ._import.import_to_gluon import import_to_gluon
+from .onnx2mx.import_model import import_model, get_model_metadata
+from .onnx2mx.import_to_gluon import import_to_gluon
+from .mx2onnx.export_model import export_model

python/mxnet/contrib/onnx/mx2onnx/LICENSE

@@ -0,0 +1,44 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+#
+# Based on
+# https://github.com/NVIDIA/mxnet_to_onnx/blob/master/mx2onnx_converter/#
+#  Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions
+#  are met:
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of NVIDIA CORPORATION nor the names of its
+#    contributors may be used to endorse or promote products derived
+#    from this software without specific prior written permission.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+#  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+#  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+#  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+#  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+#  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+#  OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

python/mxnet/contrib/onnx/mx2onnx/__init__.py

@@ -0,0 +1,24 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+# coding: utf-8
+"""ONNX Export module"""
+from __future__ import absolute_import
+
+from . import export_model
+from . import export_onnx
+from . import _op_translations

python/mxnet/contrib/onnx/mx2onnx/_export_helper.py

@@ -0,0 +1,65 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+"""export helper functions"""
+# coding: utf-8
+import os
+import logging
+import mxnet as mx
+
+
+def load_module(sym_filepath, params_filepath):
+    """Loads the MXNet model file and
+    returns MXNet symbol and params (weights).
+
+    Parameters
+    ----------
+    json_path : str
+        Path to the json file
+    params_path : str
+        Path to the params file
+
+    Returns
+    -------
+    sym : MXNet symbol
+        Model symbol object
+
+    params : params object
+        Model weights including both arg and aux params.
+    """
+    if not (os.path.isfile(sym_filepath) and os.path.isfile(params_filepath)):
+        raise ValueError("Symbol and params files provided are invalid")
+    else:
+        try:
+            # reads symbol.json file from given path and
+            # retrieves model prefix and number of epochs
+            model_name = sym_filepath.rsplit('.', 1)[0].rsplit('-', 1)[0]
+            params_file_list = params_filepath.rsplit('.', 1)[0].rsplit('-', 1)
+            # Setting num_epochs to 0 if not present in filename
+            num_epochs = 0 if len(params_file_list) == 1 else int(params_file_list[1])
+        except IndexError:
+            logging.info("Model and params name should be in format: "
+                         "prefix-symbol.json, prefix-epoch.params")
+            raise
+
+        sym, arg_params, aux_params = mx.model.load_checkpoint(model_name, num_epochs)
+
+        # Merging arg and aux parameters
+        params = {}
+        params.update(arg_params)
+        params.update(aux_params)
+
+        return sym, params