PulseFocusPlatform/ppdet/modeling/reid/resnet.py

321 lines
11 KiB
Python

# copyright (c) 2021 PaddlePaddle Authors. All Rights Reserve.
#
# 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.
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import os
import math
import paddle
from paddle import ParamAttr
import paddle.nn as nn
import paddle.nn.functional as F
from paddle.nn.initializer import Normal
__all__ = ["ResNet18", "ResNet34", "ResNet50", "ResNet101", "ResNet152"]
class ConvBNLayer(nn.Layer):
def __init__(self,
num_channels,
num_filters,
filter_size,
stride=1,
dilation=1,
groups=1,
act=None,
lr_mult=1.0,
name=None,
data_format="NCHW"):
super(ConvBNLayer, self).__init__()
conv_stdv = filter_size * filter_size * num_filters
self._conv = nn.Conv2D(
in_channels=num_channels,
out_channels=num_filters,
kernel_size=filter_size,
stride=stride,
padding=(filter_size - 1) // 2,
dilation=dilation,
groups=groups,
weight_attr=ParamAttr(
name=name + "_weights",
learning_rate=lr_mult,
initializer=Normal(0, math.sqrt(2. / conv_stdv))),
bias_attr=False,
data_format=data_format)
if name == "conv1":
bn_name = "bn_" + name
else:
bn_name = "bn" + name[3:]
self._batch_norm = nn.BatchNorm(
num_filters,
act=act,
param_attr=ParamAttr(name=bn_name + "_scale"),
bias_attr=ParamAttr(bn_name + "_offset"),
moving_mean_name=bn_name + "_mean",
moving_variance_name=bn_name + "_variance",
data_layout=data_format)
def forward(self, inputs):
y = self._conv(inputs)
y = self._batch_norm(y)
return y
class BottleneckBlock(nn.Layer):
def __init__(self,
num_channels,
num_filters,
stride,
shortcut=True,
name=None,
lr_mult=1.0,
dilation=1,
data_format="NCHW"):
super(BottleneckBlock, self).__init__()
self.conv0 = ConvBNLayer(
num_channels=num_channels,
num_filters=num_filters,
filter_size=1,
dilation=dilation,
act="relu",
lr_mult=lr_mult,
name=name + "_branch2a",
data_format=data_format)
self.conv1 = ConvBNLayer(
num_channels=num_filters,
num_filters=num_filters,
filter_size=3,
dilation=dilation,
stride=stride,
act="relu",
lr_mult=lr_mult,
name=name + "_branch2b",
data_format=data_format)
self.conv2 = ConvBNLayer(
num_channels=num_filters,
num_filters=num_filters * 4,
filter_size=1,
dilation=dilation,
act=None,
lr_mult=lr_mult,
name=name + "_branch2c",
data_format=data_format)
if not shortcut:
self.short = ConvBNLayer(
num_channels=num_channels,
num_filters=num_filters * 4,
filter_size=1,
dilation=dilation,
stride=stride,
lr_mult=lr_mult,
name=name + "_branch1",
data_format=data_format)
self.shortcut = shortcut
self._num_channels_out = num_filters * 4
def forward(self, inputs):
y = self.conv0(inputs)
conv1 = self.conv1(y)
conv2 = self.conv2(conv1)
if self.shortcut:
short = inputs
else:
short = self.short(inputs)
y = paddle.add(x=short, y=conv2)
y = F.relu(y)
return y
class BasicBlock(nn.Layer):
def __init__(self,
num_channels,
num_filters,
stride,
shortcut=True,
name=None,
data_format="NCHW"):
super(BasicBlock, self).__init__()
self.stride = stride
self.conv0 = ConvBNLayer(
num_channels=num_channels,
num_filters=num_filters,
filter_size=3,
stride=stride,
act="relu",
name=name + "_branch2a",
data_format=data_format)
self.conv1 = ConvBNLayer(
num_channels=num_filters,
num_filters=num_filters,
filter_size=3,
act=None,
name=name + "_branch2b",
data_format=data_format)
if not shortcut:
self.short = ConvBNLayer(
num_channels=num_channels,
num_filters=num_filters,
filter_size=1,
stride=stride,
name=name + "_branch1",
data_format=data_format)
self.shortcut = shortcut
def forward(self, inputs):
y = self.conv0(inputs)
conv1 = self.conv1(y)
if self.shortcut:
short = inputs
else:
short = self.short(inputs)
y = paddle.add(x=short, y=conv1)
y = F.relu(y)
return y
class ResNet(nn.Layer):
def __init__(self,
layers=50,
lr_mult=1.0,
last_conv_stride=2,
last_conv_dilation=1):
super(ResNet, self).__init__()
self.layers = layers
self.data_format = "NCHW"
self.input_image_channel = 3
supported_layers = [18, 34, 50, 101, 152]
assert layers in supported_layers, \
"supported layers are {} but input layer is {}".format(
supported_layers, layers)
if layers == 18:
depth = [2, 2, 2, 2]
elif layers == 34 or layers == 50:
depth = [3, 4, 6, 3]
elif layers == 101:
depth = [3, 4, 23, 3]
elif layers == 152:
depth = [3, 8, 36, 3]
num_channels = [64, 256, 512,
1024] if layers >= 50 else [64, 64, 128, 256]
num_filters = [64, 128, 256, 512]
self.conv = ConvBNLayer(
num_channels=self.input_image_channel,
num_filters=64,
filter_size=7,
stride=2,
act="relu",
lr_mult=lr_mult,
name="conv1",
data_format=self.data_format)
self.pool2d_max = nn.MaxPool2D(
kernel_size=3, stride=2, padding=1, data_format=self.data_format)
self.block_list = []
if layers >= 50:
for block in range(len(depth)):
shortcut = False
for i in range(depth[block]):
if layers in [101, 152] and block == 2:
if i == 0:
conv_name = "res" + str(block + 2) + "a"
else:
conv_name = "res" + str(block + 2) + "b" + str(i)
else:
conv_name = "res" + str(block + 2) + chr(97 + i)
if i != 0 or block == 0:
stride = 1
elif block == len(depth) - 1:
stride = last_conv_stride
else:
stride = 2
bottleneck_block = self.add_sublayer(
conv_name,
BottleneckBlock(
num_channels=num_channels[block]
if i == 0 else num_filters[block] * 4,
num_filters=num_filters[block],
stride=stride,
shortcut=shortcut,
name=conv_name,
lr_mult=lr_mult,
dilation=last_conv_dilation
if block == len(depth) - 1 else 1,
data_format=self.data_format))
self.block_list.append(bottleneck_block)
shortcut = True
else:
for block in range(len(depth)):
shortcut = False
for i in range(depth[block]):
conv_name = "res" + str(block + 2) + chr(97 + i)
basic_block = self.add_sublayer(
conv_name,
BasicBlock(
num_channels=num_channels[block]
if i == 0 else num_filters[block],
num_filters=num_filters[block],
stride=2 if i == 0 and block != 0 else 1,
shortcut=shortcut,
name=conv_name,
data_format=self.data_format))
self.block_list.append(basic_block)
shortcut = True
def forward(self, inputs):
y = self.conv(inputs)
y = self.pool2d_max(y)
for block in self.block_list:
y = block(y)
return y
def ResNet18(**args):
model = ResNet(layers=18, **args)
return model
def ResNet34(**args):
model = ResNet(layers=34, **args)
return model
def ResNet50(pretrained=None, **args):
model = ResNet(layers=50, **args)
if pretrained is not None:
if not (os.path.isdir(pretrained) or
os.path.exists(pretrained + '.pdparams')):
raise ValueError("Model pretrain path {} does not "
"exists.".format(pretrained))
param_state_dict = paddle.load(pretrained + '.pdparams')
model.set_dict(param_state_dict)
return model
def ResNet101(pretrained=None, **args):
model = ResNet(layers=101, **args)
if pretrained is not None:
if not (os.path.isdir(pretrained) or
os.path.exists(pretrained + '.pdparams')):
raise ValueError("Model pretrain path {} does not "
"exists.".format(pretrained))
param_state_dict = paddle.load(pretrained + '.pdparams')
model.set_dict(param_state_dict)
return model
def ResNet152(**args):
model = ResNet(layers=152, **args)
return model