|
|
|
@@ -0,0 +1,282 @@ |
|
|
|
# Copyright 2020 Huawei Technologies Co., Ltd |
|
|
|
# |
|
|
|
# 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. |
|
|
|
# ============================================================================ |
|
|
|
"""ResNet.""" |
|
|
|
import numpy as np |
|
|
|
import mindspore.nn as nn |
|
|
|
from mindspore.ops import operations as P |
|
|
|
from mindspore.common.tensor import Tensor |
|
|
|
|
|
|
|
|
|
|
|
def _weight_variable(shape, factor=0.01): |
|
|
|
init_value = np.random.randn(*shape).astype(np.float32) * factor |
|
|
|
return Tensor(init_value) |
|
|
|
|
|
|
|
|
|
|
|
def _conv3x3(in_channel, out_channel, stride=1): |
|
|
|
weight_shape = (out_channel, in_channel, 3, 3) |
|
|
|
weight = _weight_variable(weight_shape) |
|
|
|
return nn.Conv2d(in_channel, out_channel, |
|
|
|
kernel_size=3, stride=stride, padding=0, pad_mode='same', weight_init=weight) |
|
|
|
|
|
|
|
|
|
|
|
def _conv1x1(in_channel, out_channel, stride=1): |
|
|
|
weight_shape = (out_channel, in_channel, 1, 1) |
|
|
|
weight = _weight_variable(weight_shape) |
|
|
|
return nn.Conv2d(in_channel, out_channel, |
|
|
|
kernel_size=1, stride=stride, padding=0, pad_mode='same', weight_init=weight) |
|
|
|
|
|
|
|
|
|
|
|
def _conv7x7(in_channel, out_channel, stride=1): |
|
|
|
weight_shape = (out_channel, in_channel, 7, 7) |
|
|
|
weight = _weight_variable(weight_shape) |
|
|
|
return nn.Conv2d(in_channel, out_channel, |
|
|
|
kernel_size=7, stride=stride, padding=0, pad_mode='same', weight_init=weight) |
|
|
|
|
|
|
|
|
|
|
|
def _bn(channel): |
|
|
|
return nn.BatchNorm2d(channel, eps=1e-4, momentum=0.9, |
|
|
|
gamma_init=1, beta_init=0, moving_mean_init=0, moving_var_init=1) |
|
|
|
|
|
|
|
|
|
|
|
def _bn_last(channel): |
|
|
|
return nn.BatchNorm2d(channel, eps=1e-4, momentum=0.9, |
|
|
|
gamma_init=0, beta_init=0, moving_mean_init=0, moving_var_init=1) |
|
|
|
|
|
|
|
|
|
|
|
def _fc(in_channel, out_channel): |
|
|
|
weight_shape = (out_channel, in_channel) |
|
|
|
weight = _weight_variable(weight_shape) |
|
|
|
return nn.Dense(in_channel, out_channel, has_bias=True, weight_init=weight, bias_init=0) |
|
|
|
|
|
|
|
|
|
|
|
class ResidualBlock(nn.Cell): |
|
|
|
""" |
|
|
|
ResNet V1 residual block definition. |
|
|
|
|
|
|
|
Args: |
|
|
|
in_channel (int): Input channel. |
|
|
|
out_channel (int): Output channel. |
|
|
|
stride (int): Stride size for the first convolutional layer. Default: 1. |
|
|
|
|
|
|
|
Returns: |
|
|
|
Tensor, output tensor. |
|
|
|
|
|
|
|
Examples: |
|
|
|
>>> ResidualBlock(3, 256, stride=2) |
|
|
|
""" |
|
|
|
expansion = 4 |
|
|
|
|
|
|
|
def __init__(self, |
|
|
|
in_channel, |
|
|
|
out_channel, |
|
|
|
stride=1): |
|
|
|
super(ResidualBlock, self).__init__() |
|
|
|
|
|
|
|
channel = out_channel // self.expansion |
|
|
|
self.conv1 = _conv1x1(in_channel, channel, stride=1) |
|
|
|
self.bn1 = _bn(channel) |
|
|
|
|
|
|
|
self.conv2 = _conv3x3(channel, channel, stride=stride) |
|
|
|
self.bn2 = _bn(channel) |
|
|
|
|
|
|
|
self.conv3 = _conv1x1(channel, out_channel, stride=1) |
|
|
|
self.bn3 = _bn_last(out_channel) |
|
|
|
|
|
|
|
self.relu = nn.ReLU() |
|
|
|
|
|
|
|
self.down_sample = False |
|
|
|
|
|
|
|
if stride != 1 or in_channel != out_channel: |
|
|
|
self.down_sample = True |
|
|
|
self.down_sample_layer = None |
|
|
|
|
|
|
|
if self.down_sample: |
|
|
|
self.down_sample_layer = nn.SequentialCell([_conv1x1(in_channel, out_channel, stride), |
|
|
|
_bn(out_channel)]) |
|
|
|
self.add = P.TensorAdd() |
|
|
|
|
|
|
|
def construct(self, x): |
|
|
|
identity = x |
|
|
|
|
|
|
|
out = self.conv1(x) |
|
|
|
out = self.bn1(out) |
|
|
|
out = self.relu(out) |
|
|
|
|
|
|
|
out = self.conv2(out) |
|
|
|
out = self.bn2(out) |
|
|
|
out = self.relu(out) |
|
|
|
|
|
|
|
out = self.conv3(out) |
|
|
|
out = self.bn3(out) |
|
|
|
|
|
|
|
if self.down_sample: |
|
|
|
identity = self.down_sample_layer(identity) |
|
|
|
|
|
|
|
out = self.add(out, identity) |
|
|
|
out = self.relu(out) |
|
|
|
|
|
|
|
return out |
|
|
|
|
|
|
|
|
|
|
|
class ResNet(nn.Cell): |
|
|
|
""" |
|
|
|
ResNet architecture. |
|
|
|
|
|
|
|
Args: |
|
|
|
block (Cell): Block for network. |
|
|
|
layer_nums (list): Numbers of block in different layers. |
|
|
|
in_channels (list): Input channel in each layer. |
|
|
|
out_channels (list): Output channel in each layer. |
|
|
|
strides (list): Stride size in each layer. |
|
|
|
num_classes (int): The number of classes that the training images are belonging to. |
|
|
|
Returns: |
|
|
|
Tensor, output tensor. |
|
|
|
|
|
|
|
Examples: |
|
|
|
>>> ResNet(ResidualBlock, |
|
|
|
>>> [3, 4, 6, 3], |
|
|
|
>>> [64, 256, 512, 1024], |
|
|
|
>>> [256, 512, 1024, 2048], |
|
|
|
>>> [1, 2, 2, 2], |
|
|
|
>>> 10) |
|
|
|
""" |
|
|
|
|
|
|
|
def __init__(self, |
|
|
|
block, |
|
|
|
layer_nums, |
|
|
|
in_channels, |
|
|
|
out_channels, |
|
|
|
strides, |
|
|
|
num_classes): |
|
|
|
super(ResNet, self).__init__() |
|
|
|
|
|
|
|
if not len(layer_nums) == len(in_channels) == len(out_channels) == 4: |
|
|
|
raise ValueError("the length of layer_num, in_channels, out_channels list must be 4!") |
|
|
|
|
|
|
|
self.conv1 = _conv7x7(3, 64, stride=2) |
|
|
|
self.bn1 = _bn(64) |
|
|
|
self.relu = P.ReLU() |
|
|
|
self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, pad_mode="same") |
|
|
|
|
|
|
|
self.layer1 = self._make_layer(block, |
|
|
|
layer_nums[0], |
|
|
|
in_channel=in_channels[0], |
|
|
|
out_channel=out_channels[0], |
|
|
|
stride=strides[0]) |
|
|
|
self.layer2 = self._make_layer(block, |
|
|
|
layer_nums[1], |
|
|
|
in_channel=in_channels[1], |
|
|
|
out_channel=out_channels[1], |
|
|
|
stride=strides[1]) |
|
|
|
self.layer3 = self._make_layer(block, |
|
|
|
layer_nums[2], |
|
|
|
in_channel=in_channels[2], |
|
|
|
out_channel=out_channels[2], |
|
|
|
stride=strides[2]) |
|
|
|
self.layer4 = self._make_layer(block, |
|
|
|
layer_nums[3], |
|
|
|
in_channel=in_channels[3], |
|
|
|
out_channel=out_channels[3], |
|
|
|
stride=strides[3]) |
|
|
|
|
|
|
|
self.mean = P.ReduceMean(keep_dims=True) |
|
|
|
self.flatten = nn.Flatten() |
|
|
|
self.end_point = _fc(out_channels[3], num_classes) |
|
|
|
|
|
|
|
def _make_layer(self, block, layer_num, in_channel, out_channel, stride): |
|
|
|
""" |
|
|
|
Make stage network of ResNet. |
|
|
|
|
|
|
|
Args: |
|
|
|
block (Cell): Resnet block. |
|
|
|
layer_num (int): Layer number. |
|
|
|
in_channel (int): Input channel. |
|
|
|
out_channel (int): Output channel. |
|
|
|
stride (int): Stride size for the first convolutional layer. |
|
|
|
|
|
|
|
Returns: |
|
|
|
SequentialCell, the output layer. |
|
|
|
|
|
|
|
Examples: |
|
|
|
>>> _make_layer(ResidualBlock, 3, 128, 256, 2) |
|
|
|
""" |
|
|
|
layers = [] |
|
|
|
|
|
|
|
resnet_block = block(in_channel, out_channel, stride=stride) |
|
|
|
layers.append(resnet_block) |
|
|
|
|
|
|
|
for _ in range(1, layer_num): |
|
|
|
resnet_block = block(out_channel, out_channel, stride=1) |
|
|
|
layers.append(resnet_block) |
|
|
|
|
|
|
|
return nn.SequentialCell(layers) |
|
|
|
|
|
|
|
def construct(self, x): |
|
|
|
x = self.conv1(x) |
|
|
|
x = self.bn1(x) |
|
|
|
x = self.relu(x) |
|
|
|
c1 = self.maxpool(x) |
|
|
|
|
|
|
|
c2 = self.layer1(c1) |
|
|
|
c3 = self.layer2(c2) |
|
|
|
c4 = self.layer3(c3) |
|
|
|
c5 = self.layer4(c4) |
|
|
|
|
|
|
|
out = self.mean(c5, (2, 3)) |
|
|
|
out = self.flatten(out) |
|
|
|
out = self.end_point(out) |
|
|
|
|
|
|
|
return out |
|
|
|
|
|
|
|
|
|
|
|
def resnet50(class_num=10): |
|
|
|
""" |
|
|
|
Get ResNet50 neural network. |
|
|
|
|
|
|
|
Args: |
|
|
|
class_num (int): Class number. |
|
|
|
|
|
|
|
Returns: |
|
|
|
Cell, cell instance of ResNet50 neural network. |
|
|
|
|
|
|
|
Examples: |
|
|
|
>>> net = resnet50(10) |
|
|
|
""" |
|
|
|
return ResNet(ResidualBlock, |
|
|
|
[3, 4, 6, 3], |
|
|
|
[64, 256, 512, 1024], |
|
|
|
[256, 512, 1024, 2048], |
|
|
|
[1, 2, 2, 2], |
|
|
|
class_num) |
|
|
|
|
|
|
|
def resnet101(class_num=1001): |
|
|
|
""" |
|
|
|
Get ResNet101 neural network. |
|
|
|
|
|
|
|
Args: |
|
|
|
class_num (int): Class number. |
|
|
|
|
|
|
|
Returns: |
|
|
|
Cell, cell instance of ResNet101 neural network. |
|
|
|
|
|
|
|
Examples: |
|
|
|
>>> net = resnet101(1001) |
|
|
|
""" |
|
|
|
return ResNet(ResidualBlock, |
|
|
|
[3, 4, 23, 3], |
|
|
|
[64, 256, 512, 1024], |
|
|
|
[256, 512, 1024, 2048], |
|
|
|
[1, 2, 2, 2], |
|
|
|
class_num) |