DeepLearningExamples/PyTorch/Classification/ConvNets/image_classification/models/resnet.py
2021-11-09 13:42:18 -08:00

457 lines
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Python

# Copyright (c) 2018-2019, NVIDIA CORPORATION
# Copyright (c) 2017- Facebook, Inc
#
# 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 the copyright holder 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 AND CONTRIBUTORS "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 HOLDER 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,
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import argparse
from collections import OrderedDict
from dataclasses import dataclass
from typing import List, Dict, Callable, Any, Type
import torch
import torch.nn as nn
from .common import (
SqueezeAndExcitation,
LayerBuilder,
SqueezeAndExcitationTRT,
)
from .model import (
Model,
ModelParams,
ModelArch,
EntryPoint,
)
__all__ = ["ResNet", "resnet_configs"]
# BasicBlock {{{
class BasicBlock(nn.Module):
def __init__(
self,
builder,
inplanes,
planes,
expansion,
stride=1,
cardinality=1,
downsample=None,
last_bn_0_init=False,
):
super(BasicBlock, self).__init__()
self.conv1 = builder.conv3x3(inplanes, planes, stride, cardinality=cardinality)
self.bn1 = builder.batchnorm(planes)
self.relu = builder.activation()
self.conv2 = builder.conv3x3(
planes, planes * expansion, cardinality=cardinality
)
self.bn2 = builder.batchnorm(planes * expansion, zero_init=last_bn_0_init)
self.downsample = downsample
self.stride = stride
def forward(self, x):
residual = x
out = self.conv1(x)
if self.bn1 is not None:
out = self.bn1(out)
out = self.relu(out)
out = self.conv2(out)
if self.bn2 is not None:
out = self.bn2(out)
if self.downsample is not None:
residual = self.downsample(x)
out += residual
out = self.relu(out)
return out
# BasicBlock }}}
# Bottleneck {{{
class Bottleneck(nn.Module):
def __init__(
self,
builder,
inplanes,
planes,
expansion,
stride=1,
cardinality=1,
se=False,
se_squeeze=16,
downsample=None,
fused_se=True,
last_bn_0_init=False,
trt=False,
):
super(Bottleneck, self).__init__()
self.conv1 = builder.conv1x1(inplanes, planes)
self.bn1 = builder.batchnorm(planes)
self.conv2 = builder.conv3x3(planes, planes, groups=cardinality, stride=stride)
self.bn2 = builder.batchnorm(planes)
self.conv3 = builder.conv1x1(planes, planes * expansion)
self.bn3 = builder.batchnorm(planes * expansion, zero_init=last_bn_0_init)
self.relu = builder.activation()
self.downsample = downsample
self.stride = stride
self.fused_se = fused_se
if se:
self.squeeze = (
SqueezeAndExcitation(
planes * expansion, se_squeeze, builder.activation()
)
if not trt
else SqueezeAndExcitationTRT(
planes * expansion, se_squeeze, builder.activation()
)
)
else:
self.squeeze = None
def forward(self, x):
residual = 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.downsample is not None:
residual = self.downsample(x)
if self.squeeze is None:
out += residual
else:
if self.fused_se:
out = torch.addcmul(residual, out, self.squeeze(out), value=1)
else:
out = residual + out * self.squeeze(out)
out = self.relu(out)
return out
class SEBottleneck(Bottleneck):
def __init__(
self,
builder,
inplanes,
planes,
expansion,
stride=1,
cardinality=1,
downsample=None,
fused_se=True,
last_bn_0_init=False,
trt=False,
):
super(SEBottleneck, self).__init__(
builder,
inplanes,
planes,
expansion,
stride=stride,
cardinality=cardinality,
se=True,
se_squeeze=16,
downsample=downsample,
fused_se=fused_se,
last_bn_0_init=last_bn_0_init,
trt=trt,
)
# Bottleneck }}}
class ResNet(nn.Module):
@dataclass
class Arch(ModelArch):
block: Type[Bottleneck]
layers: List[int] # arch
widths: List[int] # arch
expansion: int
cardinality: int = 1
stem_width: int = 64
activation: str = "relu"
default_image_size: int = 224
@dataclass
class Params(ModelParams):
num_classes: int = 1000
last_bn_0_init: bool = False
conv_init: str = "fan_in"
trt: bool = False
fused_se: bool = True
def parser(self, name):
p = super().parser(name)
p.add_argument(
"--num_classes",
metavar="N",
default=self.num_classes,
type=int,
help="number of classes",
)
p.add_argument(
"--last_bn_0_init",
metavar="True|False",
default=self.last_bn_0_init,
type=bool,
)
p.add_argument(
"--conv_init",
default=self.conv_init,
choices=["fan_in", "fan_out"],
type=str,
help="initialization mode for convolutional layers, see https://pytorch.org/docs/stable/nn.init.html#torch.nn.init.kaiming_normal_",
)
p.add_argument("--trt", metavar="True|False", default=self.trt, type=bool)
p.add_argument(
"--fused_se", metavar="True|False", default=self.fused_se, type=bool
)
return p
def __init__(
self,
arch: Arch,
num_classes: int = 1000,
last_bn_0_init: bool = False,
conv_init: str = "fan_in",
trt: bool = False,
fused_se: bool = True,
):
super(ResNet, self).__init__()
self.arch = arch
self.builder = LayerBuilder(
LayerBuilder.Config(activation=arch.activation, conv_init=conv_init)
)
self.last_bn_0_init = last_bn_0_init
self.conv1 = self.builder.conv7x7(3, arch.stem_width, stride=2)
self.bn1 = self.builder.batchnorm(arch.stem_width)
self.relu = self.builder.activation()
self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
inplanes = arch.stem_width
assert len(arch.widths) == len(arch.layers)
self.num_layers = len(arch.widths)
layers = []
for i, (w, l) in enumerate(zip(arch.widths, arch.layers)):
layer, inplanes = self._make_layer(
arch.block,
arch.expansion,
inplanes,
w,
l,
cardinality=arch.cardinality,
stride=1 if i == 0 else 2,
trt=trt,
fused_se=fused_se,
)
layers.append(layer)
self.layers = nn.Sequential(*layers)
self.avgpool = nn.AdaptiveAvgPool2d(1)
self.fc = nn.Linear(arch.widths[-1] * arch.expansion, num_classes)
def stem(self, x):
x = self.conv1(x)
if self.bn1 is not None:
x = self.bn1(x)
x = self.relu(x)
x = self.maxpool(x)
return x
def classifier(self, x):
x = self.avgpool(x)
x = x.view(x.size(0), -1)
x = self.fc(x)
return x
def forward(self, x):
x = self.stem(x)
x = self.layers(x)
x = self.classifier(x)
return x
def extract_features(self, x, layers=None):
if layers is None:
layers = [f"layer{i+1}" for i in range(self.num_layers)] + ["classifier"]
run = [
i
for i in range(self.num_layers)
if "classifier" in layers
or any([f"layer{j+1}" in layers for j in range(i, self.num_layers)])
]
output = {}
x = self.stem(x)
for l in run:
fn = self.layers[l]
x = fn(x)
if f"layer{l+1}" in layers:
output[f"layer{l+1}"] = x
if "classifier" in layers:
output["classifier"] = self.classifier(x)
return output
# helper functions {{{
def _make_layer(
self,
block,
expansion,
inplanes,
planes,
blocks,
stride=1,
cardinality=1,
trt=False,
fused_se=True,
):
downsample = None
if stride != 1 or inplanes != planes * expansion:
dconv = self.builder.conv1x1(inplanes, planes * expansion, stride=stride)
dbn = self.builder.batchnorm(planes * expansion)
if dbn is not None:
downsample = nn.Sequential(dconv, dbn)
else:
downsample = dconv
layers = []
for i in range(blocks):
layers.append(
block(
self.builder,
inplanes,
planes,
expansion,
stride=stride if i == 0 else 1,
cardinality=cardinality,
downsample=downsample if i == 0 else None,
fused_se=fused_se,
last_bn_0_init=self.last_bn_0_init,
trt=trt,
)
)
inplanes = planes * expansion
return nn.Sequential(*layers), inplanes
def ngc_checkpoint_remap(self, url=None, version=None):
if version is None:
version = url.split("/")[8]
def to_sequential_remap(s):
splited = s.split(".")
if splited[0].startswith("layer"):
return ".".join(
["layers." + str(int(splited[0][len("layer") :]) - 1)] + splited[1:]
)
else:
return s
def no_remap(s):
return s
return {"20.06.0": to_sequential_remap}.get(version, no_remap)
# }}}
__models: Dict[str, Model] = {
"resnet50": Model(
constructor=ResNet,
arch=ResNet.Arch(
stem_width=64,
block=Bottleneck,
layers=[3, 4, 6, 3],
widths=[64, 128, 256, 512],
expansion=4,
default_image_size=224,
),
params=ResNet.Params(),
checkpoint_url="https://api.ngc.nvidia.com/v2/models/nvidia/resnet50_pyt_amp/versions/20.06.0/files/nvidia_resnet50_200821.pth.tar",
),
"resnext101-32x4d": Model(
constructor=ResNet,
arch=ResNet.Arch(
stem_width=64,
block=Bottleneck,
layers=[3, 4, 23, 3],
widths=[128, 256, 512, 1024],
expansion=2,
cardinality=32,
default_image_size=224,
),
params=ResNet.Params(),
checkpoint_url="https://api.ngc.nvidia.com/v2/models/nvidia/resnext101_32x4d_pyt_amp/versions/20.06.0/files/nvidia_resnext101-32x4d_200821.pth.tar",
),
"se-resnext101-32x4d": Model(
constructor=ResNet,
arch=ResNet.Arch(
stem_width=64,
block=SEBottleneck,
layers=[3, 4, 23, 3],
widths=[128, 256, 512, 1024],
expansion=2,
cardinality=32,
default_image_size=224,
),
params=ResNet.Params(),
checkpoint_url="https://api.ngc.nvidia.com/v2/models/nvidia/seresnext101_32x4d_pyt_amp/versions/20.06.0/files/nvidia_se-resnext101-32x4d_200821.pth.tar",
),
}
_ce = lambda n: EntryPoint(n, __models[n])
resnet50 = _ce("resnet50")
resnext101_32x4d = _ce("resnext101-32x4d")
se_resnext101_32x4d = _ce("se-resnext101-32x4d")