231 lines
8.5 KiB
Python
231 lines
8.5 KiB
Python
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import math
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import torch.nn as nn
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from torch.hub import load_state_dict_from_url
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from typing import Type, Any, Callable, Union, List, Optional
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from torch import Tensor
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model_urls = {
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'resnet50': 'https://github.com/bubbliiiing/pspnet-pytorch/releases/download/v1.0/resnet50s-a75c83cf.pth',
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'resnet101': '',
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}
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class BasicBlock(nn.Module):
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expansion: int = 1
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def __init__(
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self,
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inplanes: int,
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planes: int,
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stride: int = 1,
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downsample: Optional[nn.Module] = None,
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groups: int = 1,
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base_width: int = 64,
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dilation: int = 1,
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norm_layer: Optional[Callable[..., nn.Module]] = None
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) -> None:
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super(BasicBlock, self).__init__()
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if norm_layer is None:
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norm_layer = nn.BatchNorm2d
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if groups != 1 or base_width != 64:
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raise ValueError('BasicBlock only supports groups=1 and base_width=64')
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if dilation > 1:
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raise NotImplementedError("Dilation > 1 not supported in BasicBlock")
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# Both self.conv1 and self.downsample layers downsample the input when stride != 1
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self.conv1 = conv3x3(inplanes, planes, stride)
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self.bn1 = norm_layer(planes)
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self.relu = nn.ReLU(inplace=True)
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self.conv2 = conv3x3(planes, planes)
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self.bn2 = norm_layer(planes)
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self.downsample = downsample
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self.stride = stride
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def forward(self, x: Tensor) -> Tensor:
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identity = x
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out = self.conv1(x)
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out = self.bn1(out)
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out = self.relu(out)
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out = self.conv2(out)
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out = self.bn2(out)
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if self.downsample is not None:
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identity = self.downsample(x)
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out += identity
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out = self.relu(out)
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return out
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def conv3x3(in_planes, out_planes, stride=1):
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"3x3 convolution with padding"
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return nn.Conv2d(in_planes, out_planes, kernel_size=3, stride=stride,
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padding=1, bias=False)
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class Bottleneck(nn.Module):
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expansion = 4
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def __init__(self, inplanes, planes, stride=1, dilation=1, downsample=None, previous_dilation=1,
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norm_layer=None):
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super(Bottleneck, self).__init__()
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self.conv1 = nn.Conv2d(inplanes, planes, kernel_size=1, bias=False)
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self.bn1 = norm_layer(planes)
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self.conv2 = nn.Conv2d(planes, planes, kernel_size=3, stride=stride, padding=dilation, dilation=dilation,
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bias=False)
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self.bn2 = norm_layer(planes)
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self.conv3 = nn.Conv2d(planes, planes * 4, kernel_size=1, bias=False)
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self.bn3 = norm_layer(planes * 4)
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self.relu = nn.ReLU(inplace=True)
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self.downsample = downsample
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self.dilation = dilation
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self.stride = stride
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def forward(self, x):
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residual = x
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out = self.conv1(x)
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out = self.bn1(out)
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out = self.relu(out)
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out = self.conv2(out)
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out = self.bn2(out)
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out = self.relu(out)
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out = self.conv3(out)
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out = self.bn3(out)
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if self.downsample is not None:
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residual = self.downsample(x)
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out += residual
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out = self.relu(out)
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return out
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class ResNet(nn.Module):
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def __init__(self, block, layers, num_classes=1000, dilated=False, deep_base=True, norm_layer=nn.BatchNorm2d):
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self.inplanes = 128 if deep_base else 64
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super(ResNet, self).__init__()
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if deep_base:
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self.conv1 = nn.Sequential(
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nn.Conv2d(3, 64, kernel_size=3, stride=2, padding=1, bias=False),
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norm_layer(64),
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nn.ReLU(inplace=True),
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nn.Conv2d(64, 64, kernel_size=3, stride=1, padding=1, bias=False),
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norm_layer(64),
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nn.ReLU(inplace=True),
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nn.Conv2d(64, 128, kernel_size=3, stride=1, padding=1, bias=False),
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)
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else:
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self.conv1 = nn.Conv2d(3, 64, kernel_size=7, stride=2, padding=3,
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bias=False)
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self.bn1 = norm_layer(self.inplanes)
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self.relu = nn.ReLU(inplace=True)
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self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
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self.layer1 = self._make_layer(block, 64, layers[0], norm_layer=norm_layer)
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self.layer2 = self._make_layer(block, 128, layers[1], stride=2, norm_layer=norm_layer)
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if dilated:
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self.layer3 = self._make_layer(block, 256, layers[2], stride=1,
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dilation=2, norm_layer=norm_layer)
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self.layer4 = self._make_layer(block, 512, layers[3], stride=1,
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dilation=4, norm_layer=norm_layer)
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else:
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self.layer3 = self._make_layer(block, 256, layers[2], stride=2,
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norm_layer=norm_layer)
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self.layer4 = self._make_layer(block, 512, layers[3], stride=2,
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norm_layer=norm_layer)
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self.avgpool = nn.AvgPool2d(7, stride=1)
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self.fc = nn.Linear(512 * block.expansion, num_classes)
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for m in self.modules():
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if isinstance(m, nn.Conv2d):
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n = m.kernel_size[0] * m.kernel_size[1] * m.out_channels
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m.weight.data.normal_(0, math.sqrt(2. / n))
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elif isinstance(m, norm_layer):
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m.weight.data.fill_(1)
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m.bias.data.zero_()
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def _make_layer(self, block, planes, blocks, stride=1, dilation=1, norm_layer=None, multi_grid=False):
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downsample = None
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if stride != 1 or self.inplanes != planes * block.expansion:
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downsample = nn.Sequential(
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nn.Conv2d(self.inplanes, planes * block.expansion,
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kernel_size=1, stride=stride, bias=False),
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norm_layer(planes * block.expansion),
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)
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layers = []
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multi_dilations = [4, 8, 16]
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if multi_grid:
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layers.append(block(self.inplanes, planes, stride, dilation=multi_dilations[0],
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downsample=downsample, previous_dilation=dilation, norm_layer=norm_layer))
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elif dilation == 1 or dilation == 2:
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layers.append(block(self.inplanes, planes, stride, dilation=1,
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downsample=downsample, previous_dilation=dilation, norm_layer=norm_layer))
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elif dilation == 4:
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layers.append(block(self.inplanes, planes, stride, dilation=2,
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downsample=downsample, previous_dilation=dilation, norm_layer=norm_layer))
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else:
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raise RuntimeError("=> unknown dilation size: {}".format(dilation))
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self.inplanes = planes * block.expansion
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for i in range(1, blocks):
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if multi_grid:
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layers.append(block(self.inplanes, planes, dilation=multi_dilations[i],
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previous_dilation=dilation, norm_layer=norm_layer))
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else:
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layers.append(block(self.inplanes, planes, dilation=dilation, previous_dilation=dilation,
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norm_layer=norm_layer))
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return nn.Sequential(*layers)
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def forward(self, x):
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x = self.conv1(x)
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x = self.bn1(x)
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x = self.relu(x)
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x = self.maxpool(x)
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x = self.layer1(x)
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x = self.layer2(x)
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x = self.layer3(x)
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x = self.layer4(x)
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x = self.avgpool(x)
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x = x.view(x.size(0), -1)
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x = self.fc(x)
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return x
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def resnet50(pretrained=False, **kwargs):
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model = ResNet(Bottleneck, [3, 4, 6, 3], **kwargs)
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if pretrained:
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model.load_state_dict(load_state_dict_from_url(model_urls['resnet50'], "./model_data"), strict=False)
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return model
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def resnet101(pretrained=False, **kwargs):
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model = ResNet(Bottleneck, [3, 4, 23, 3], **kwargs)
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# if pretrained:
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# model.load_state_dict(load_state_dict_from_url(model_urls['resnet101'], "./model_data"), strict=False)
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return model
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def resnet18(pretrained: bool = False, progress: bool = True, **kwargs):
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r"""ResNet-18 model from
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`"Deep Residual Learning for Image Recognition" <https://arxiv.org/pdf/1512.03385.pdf>`_.
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Args:
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pretrained (bool): If True, returns a model pre-trained on ImageNet
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progress (bool): If True, displays a progress bar of the download to stderr
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"""
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model = ResNet(BasicBlock, [2, 2, 2, 2], **kwargs)
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return model
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