下载resnet50的模型权重的pytorch代码
时间: 2024-06-14 10:06:50 浏览: 212
以下是使用PyTorch下载ResNet50模型权重的代码示例:
```python
import torch
import torchvision.models as models
# 下载ResNet50模型权重
model = models.resnet50(pretrained=True)
# 保存模型权重
torch.save(model.state_dict(), 'resnet50.pth')
```
请注意,上述代码中的`pretrained=True`参数将自动下载并加载ResNet50模型的预训练权重。下载完成后,可以使用`torch.save()`函数将权重保存到指定的文件中(此处为'resnet50.pth')。
相关问题
resnet50预训练权重pytorch
你可以在PyTorch官方的模型库中找到ResNet-50的预训练权重。你可以使用以下代码来加载ResNet-50的预训练权重:
```python
import torch
import torchvision.models as models
# 加载预训练权重
resnet = models.resnet50(pretrained=True)
# 保存权重
torch.save(resnet.state_dict(), 'resnet50_weights.pth')
```
在上面的代码中,我们使用`torchvision.models`模块中的`resnet50`函数来加载ResNet-50的预训练模型。然后,我们可以使用`state_dict()`方法来获取模型的权重,并使用`torch.save()`函数将权重保存到一个.pth文件中。
希望这能帮到你!如果你还有其他问题,请随时问。
给出ResNet50的pytorch代码,并详细注释
以下是使用PyTorch实现ResNet50模型的完整代码,注释已经添加在代码中:
```python
import torch.nn as nn
import torch.utils.model_zoo as model_zoo
# 定义ResNet50模型
class ResNet50(nn.Module):
def __init__(self, num_classes=1000):
super(ResNet50, self).__init__()
self.inplanes = 64
self.conv1 = nn.Conv2d(3, 64, kernel_size=7, stride=2, padding=3, bias=False)
self.bn1 = nn.BatchNorm2d(64)
self.relu = nn.ReLU(inplace=True)
self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.layer1 = self._make_layer(Bottleneck, 64, 3)
self.layer2 = self._make_layer(Bottleneck, 128, 4, stride=2)
self.layer3 = self._make_layer(Bottleneck, 256, 6, stride=2)
self.layer4 = self._make_layer(Bottleneck, 512, 3, stride=2)
self.avgpool = nn.AdaptiveAvgPool2d((1, 1))
self.fc = nn.Linear(512 * Bottleneck.expansion, num_classes)
# 初始化权重
for m in self.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')
elif isinstance(m, nn.BatchNorm2d):
nn.init.constant_(m.weight, 1)
nn.init.constant_(m.bias, 0)
# 定义Bottleneck块
def _make_layer(self, block, planes, blocks, stride=1):
downsample = None
if stride != 1 or self.inplanes != planes * block.expansion:
downsample = nn.Sequential(
nn.Conv2d(self.inplanes, planes * block.expansion,
kernel_size=1, stride=stride, bias=False),
nn.BatchNorm2d(planes * block.expansion),
)
layers = []
layers.append(block(self.inplanes, planes, stride, downsample))
self.inplanes = planes * block.expansion
for _ in range(1, blocks):
layers.append(block(self.inplanes, planes))
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.avgpool(x)
x = x.view(x.size(0), -1)
x = self.fc(x)
return x
# 定义Bottleneck块
class Bottleneck(nn.Module):
expansion = 4
def __init__(self, inplanes, planes, stride=1, downsample=None):
super(Bottleneck, self).__init__()
self.conv1 = nn.Conv2d(inplanes, planes, kernel_size=1, bias=False)
self.bn1 = nn.BatchNorm2d(planes)
self.conv2 = nn.Conv2d(planes, planes, kernel_size=3, stride=stride,
padding=1, bias=False)
self.bn2 = nn.BatchNorm2d(planes)
self.conv3 = nn.Conv2d(planes, planes * self.expansion, kernel_size=1, bias=False)
self.bn3 = nn.BatchNorm2d(planes * self.expansion)
self.relu = nn.ReLU(inplace=True)
self.downsample = downsample
self.stride = stride
def forward(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.downsample is not None:
identity = self.downsample(x)
out += identity
out = self.relu(out)
return out
# 加载ImageNet预训练模型
def resnet50(pretrained=True, **kwargs):
model = ResNet50(**kwargs)
if pretrained:
model.load_state_dict(model_zoo.load_url(model_urls['resnet50']))
return model
```
在上面的代码中,我们首先定义了ResNet50模型,包括卷积层、批归一化层、Bottleneck块、全局平均池化层和全连接层。然后,我们定义了Bottleneck块,包括三个卷积层和批归一化层。最后,我们提供了加载ImageNet预训练模型的函数resnet50。
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