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import torch
import torch.nn as nn
import torch.nn.functional as F
from torch.autograd import Variable
import math
from functools import partial
__all__ = [
'ResNet', 'resnet10', 'resnet18', 'resnet34', 'resnet50', 'resnet101',
'resnet152', 'resnet200'
]
def conv3x3x3(in_planes, out_planes, stride=1, dilation=1):
# 3x3x3 convolution with padding
return nn.Conv3d(
in_planes,
out_planes,
kernel_size=3,
dilation=dilation,
stride=stride,
padding=dilation,
bias=False)
def downsample_basic_block(x, planes, stride, no_cuda=False):
out = F.avg_pool3d(x, kernel_size=1, stride=stride)
zero_pads = torch.Tensor(
out.size(0), planes - out.size(1), out.size(2), out.size(3),
out.size(4)).zero_()
if not no_cuda:
if isinstance(out.data, torch.cuda.FloatTensor):
zero_pads = zero_pads.cuda()
out = Variable(torch.cat([out.data, zero_pads], dim=1))
return out
class BasicBlock(nn.Module):
expansion = 1
def __init__(self, inplanes, planes, stride=1, dilation=1, downsample=None):
super(BasicBlock, self).__init__()
self.conv1 = conv3x3x3(inplanes, planes, stride=stride, dilation=dilation)
self.bn1 = nn.BatchNorm3d(planes)
self.relu = nn.ReLU(inplace=True)
self.conv2 = conv3x3x3(planes, planes, dilation=dilation)
self.bn2 = nn.BatchNorm3d(planes)
self.downsample = downsample
self.stride = stride
self.dilation = dilation
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)
if self.downsample is not None:
residual = self.downsample(x)
out += residual
out = self.relu(out)
return out
class Bottleneck(nn.Module):
expansion = 4
def __init__(self, inplanes, planes, stride=1, dilation=1, downsample=None):
super(Bottleneck, self).__init__()
self.conv1 = nn.Conv3d(inplanes, planes, kernel_size=1, bias=False)
self.bn1 = nn.BatchNorm3d(planes)
self.conv2 = nn.Conv3d(
planes, planes, kernel_size=3, stride=stride, dilation=dilation, padding=dilation, bias=False)
self.bn2 = nn.BatchNorm3d(planes)
self.conv3 = nn.Conv3d(planes, planes * 4, kernel_size=1, bias=False)
self.bn3 = nn.BatchNorm3d(planes * 4)
self.relu = nn.ReLU(inplace=True)
self.downsample = downsample
self.stride = stride
self.dilation = dilation
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)
out += residual
out = self.relu(out)
return out
class ResNet(nn.Module):
def __init__(self,
block,
layers,
sample_input_D,
sample_input_H,
sample_input_W,
num_seg_classes,
shortcut_type='B',
no_cuda = False):
self.inplanes = 64
self.no_cuda = no_cuda
super(ResNet, self).__init__()
self.conv1 = nn.Conv3d(
1,
64,
kernel_size=7,
stride=(2, 2, 2),
padding=(3, 3, 3),
bias=False)
self.bn1 = nn.BatchNorm3d(64)
self.relu = nn.ReLU(inplace=True)
self.maxpool = nn.MaxPool3d(kernel_size=(3, 3, 3), stride=2, padding=1)
self.layer1 = self._make_layer(block, 64, layers[0], shortcut_type)
self.layer2 = self._make_layer(
block, 128, layers[1], shortcut_type, stride=2)
self.layer3 = self._make_layer(
block, 256, layers[2], shortcut_type, stride=1, dilation=2)
self.layer4 = self._make_layer(
block, 512, layers[3], shortcut_type, stride=1, dilation=4)
self.conv_seg = nn.Sequential(
nn.ConvTranspose3d(
512 * block.expansion,
32,
2,
stride=2
),
nn.BatchNorm3d(32),
nn.ReLU(inplace=True),
nn.Conv3d(
32,
32,
kernel_size=3,
stride=(1, 1, 1),
padding=(1, 1, 1),
bias=False),
nn.BatchNorm3d(32),
nn.ReLU(inplace=True),
nn.Conv3d(
32,
num_seg_classes,
kernel_size=1,
stride=(1, 1, 1),
bias=False)
)
for m in self.modules():
if isinstance(m, nn.Conv3d):
m.weight = nn.init.kaiming_normal_(m.weight, mode='fan_out')
elif isinstance(m, nn.BatchNorm3d):
m.weight.data.fill_(1)
m.bias.data.zero_()
def _make_layer(self, block, planes, blocks, shortcut_type, stride=1, dilation=1):
downsample = None
if stride != 1 or self.inplanes != planes * block.expansion:
if shortcut_type == 'A':
downsample = partial(
downsample_basic_block,
planes=planes * block.expansion,
stride=stride,
no_cuda=self.no_cuda)
else:
downsample = nn.Sequential(
nn.Conv3d(
self.inplanes,
planes * block.expansion,
kernel_size=1,
stride=stride,
bias=False), nn.BatchNorm3d(planes * block.expansion))
layers = []
layers.append(block(self.inplanes, planes, stride=stride, dilation=dilation, downsample=downsample))
self.inplanes = planes * block.expansion
for i in range(1, blocks):
layers.append(block(self.inplanes, planes, dilation=dilation))
return nn.Sequential(*layers)
def forward(self, x):
x = self.conv1(x)
x = self.bn1(x)
x = self.relu(x)
x = self.maxpool(x)
x = self.layer1(x)
x = self.layer2(x)
x = self.layer3(x)
x = self.layer4(x)
x = self.conv_seg(x)
return x
class ResNetClassifier(nn.Module):
def __init__(self,
block,
layers,
sample_input_D,
sample_input_H,
sample_input_W,
shortcut_type='B',
num_classes=2,
out_channels=2048,
no_cuda = False):
self.inplanes = 64
self.no_cuda = no_cuda
super(ResNetClassifier, self).__init__()
self.conv1 = nn.Conv3d(
1,
64,
kernel_size=7,
stride=(2, 2, 2),
padding=(3, 3, 3),
bias=False)
self.bn1 = nn.BatchNorm3d(64)
self.relu = nn.ReLU(inplace=True)
self.maxpool = nn.MaxPool3d(kernel_size=(3, 3, 3), stride=2, padding=1)
self.layer1 = self._make_layer(block, 64, layers[0], shortcut_type)
self.layer2 = self._make_layer(
block, 128, layers[1], shortcut_type, stride=2)
self.layer3 = self._make_layer(
block, 256, layers[2], shortcut_type, stride=1, dilation=2)
self.layer4 = self._make_layer(
block, 512, layers[3], shortcut_type, stride=1, dilation=4)
for m in self.modules():
if isinstance(m, nn.Conv3d):
m.weight = nn.init.kaiming_normal_(m.weight, mode='fan_out')
elif isinstance(m, nn.BatchNorm3d):
m.weight.data.fill_(1)
m.bias.data.zero_()
self.cls = nn.Sequential(
nn.AdaptiveMaxPool3d((1, 1, 1)),
nn.Flatten(),
nn.Linear(in_features=2048, out_features=num_classes-1),
)
self.sigmoid = nn.Sigmoid()
def _make_layer(self, block, planes, blocks, shortcut_type, stride=1, dilation=1):
downsample = None
if stride != 1 or self.inplanes != planes * block.expansion:
if shortcut_type == 'A':
downsample = partial(
downsample_basic_block,
planes=planes * block.expansion,
stride=stride,
no_cuda=self.no_cuda)
else:
downsample = nn.Sequential(
nn.Conv3d(
self.inplanes,
planes * block.expansion,
kernel_size=1,
stride=stride,
bias=False), nn.BatchNorm3d(planes * block.expansion))
layers = []
layers.append(block(self.inplanes, planes, stride=stride, dilation=dilation, downsample=downsample))
self.inplanes = planes * block.expansion
for i in range(1, blocks):
layers.append(block(self.inplanes, planes, dilation=dilation))
return nn.Sequential(*layers)
def forward(self, x):
x = self.conv1(x)
x = self.bn1(x)
x = self.relu(x)
x = self.maxpool(x)
x = self.layer1(x)
x = self.layer2(x)
x = self.layer3(x)
x = self.layer4(x)
x = self.cls(x)
x = self.sigmoid(x)
x = x.squeeze(1)
return x
def resnet10(**kwargs):
"""Constructs a ResNet-18 model.
"""
model = ResNet(BasicBlock, [1, 1, 1, 1], **kwargs)
return model
def resnet18(**kwargs):
"""Constructs a ResNet-18 model.
"""
model = ResNet(BasicBlock, [2, 2, 2, 2], **kwargs)
return model
def resnet34(**kwargs):
"""Constructs a ResNet-34 model.
"""
model = ResNet(BasicBlock, [3, 4, 6, 3], **kwargs)
return model
def resnet50(**kwargs):
"""Constructs a ResNet-50 model.
"""
model = ResNet(Bottleneck, [3, 4, 6, 3], **kwargs)
return model
def resnet101(**kwargs):
"""Constructs a ResNet-101 model.
"""
model = ResNet(Bottleneck, [3, 4, 23, 3], **kwargs)
return model
def resnet152(**kwargs):
"""Constructs a ResNet-101 model.
"""
model = ResNet(Bottleneck, [3, 8, 36, 3], **kwargs)
return model
def resnet200(**kwargs):
"""Constructs a ResNet-101 model.
"""
model = ResNet(Bottleneck, [3, 24, 36, 3], **kwargs)
return model