pytorch实现googlenet
时间: 2023-06-05 22:47:45 浏览: 172
PyTorch可以通过定义网络结构和训练过程来实现GoogleNet。
GoogleNet是一个深度卷积神经网络,由多个Inception模块组成。每个Inception模块包含多个卷积层和池化层,以及不同大小的卷积核和池化核。在PyTorch中,可以使用nn.Module来定义每个Inception模块和整个网络结构。
在训练过程中,可以使用PyTorch提供的优化器和损失函数来优化模型。常用的优化器包括SGD和Adam,常用的损失函数包括交叉熵和均方误差。
需要注意的是,GoogleNet是一个较为复杂的模型,需要较长的训练时间和大量的数据集来训练。在实现过程中,需要注意调整超参数和优化算法,以达到更好的性能。
相关问题
基Pytorch实现GoogleNet模型实现图片分类,能输出分类结果的那种,附代码
以下是基于PyTorch实现的GoogleNet模型代码,可以用于图片分类,并输出分类结果:
```python
import torch
import torch.nn as nn
import torch.nn.functional as F
class Inception_Module(nn.Module):
def __init__(self, input_channels, kernel_1x1, reduce_3x3, kernel_3x3, reduce_5x5, kernel_5x5, pool_proj):
super(Inception_Module, self).__init__()
# 1x1 conv branch
self.branch1 = nn.Conv2d(input_channels, kernel_1x1, kernel_size=1)
# 1x1 conv -> 3x3 conv branch
self.branch2 = nn.Sequential(
nn.Conv2d(input_channels, reduce_3x3, kernel_size=1),
nn.ReLU(inplace=True),
nn.Conv2d(reduce_3x3, kernel_3x3, kernel_size=3, padding=1)
)
# 1x1 conv -> 5x5 conv branch
self.branch3 = nn.Sequential(
nn.Conv2d(input_channels, reduce_5x5, kernel_size=1),
nn.ReLU(inplace=True),
nn.Conv2d(reduce_5x5, kernel_5x5, kernel_size=5, padding=2)
)
# 3x3 max pool -> 1x1 conv branch
self.branch4 = nn.Sequential(
nn.MaxPool2d(kernel_size=3, stride=1, padding=1),
nn.Conv2d(input_channels, pool_proj, kernel_size=1)
)
def forward(self, x):
branch1_output = self.branch1(x)
branch2_output = self.branch2(x)
branch3_output = self.branch3(x)
branch4_output = self.branch4(x)
outputs = [branch1_output, branch2_output, branch3_output, branch4_output]
return torch.cat(outputs, 1)
class GoogleNet(nn.Module):
def __init__(self, num_classes=1000):
super(GoogleNet, self).__init__()
self.conv1 = nn.Conv2d(3, 64, kernel_size=7, stride=2, padding=3)
self.max_pool1 = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.conv2a = nn.Conv2d(64, 64, kernel_size=1)
self.conv2b = nn.Conv2d(64, 192, kernel_size=3, padding=1)
self.max_pool2 = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.inception3a = Inception_Module(192, 64, 96, 128, 16, 32, 32)
self.inception3b = Inception_Module(256, 128, 128, 192, 32, 96, 64)
self.max_pool3 = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.inception4a = Inception_Module(480, 192, 96, 208, 16, 48, 64)
self.inception4b = Inception_Module(512, 160, 112, 224, 24, 64, 64)
self.inception4c = Inception_Module(512, 128, 128, 256, 24, 64, 64)
self.inception4d = Inception_Module(512, 112, 144, 288, 32, 64, 64)
self.inception4e = Inception_Module(528, 256, 160, 320, 32, 128, 128)
self.max_pool4 = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.inception5a = Inception_Module(832, 256, 160, 320, 32, 128, 128)
self.inception5b = Inception_Module(832, 384, 192, 384, 48, 128, 128)
self.avg_pool = nn.AdaptiveAvgPool2d((1, 1))
self.dropout = nn.Dropout(p=0.4)
self.fc1 = nn.Linear(1024, num_classes)
def forward(self, x):
x = F.relu(self.conv1(x))
x = self.max_pool1(x)
x = F.relu(self.conv2a(x))
x = F.relu(self.conv2b(x))
x = self.max_pool2(x)
x = self.inception3a(x)
x = self.inception3b(x)
x = self.max_pool3(x)
x = self.inception4a(x)
x = self.inception4b(x)
x = self.inception4c(x)
x = self.inception4d(x)
x = self.inception4e(x)
x = self.max_pool4(x)
x = self.inception5a(x)
x = self.inception5b(x)
x = self.avg_pool(x)
x = x.view(x.size(0), -1)
x = self.dropout(x)
x = self.fc1(x)
return x
```
使用时,可以像下面这样调用:
```python
model = GoogleNet(num_classes=10) # num_classes指定分类的类别数
input = torch.randn(1, 3, 224, 224) # 输入图片大小为224x224
output = model(input)
pred = output.argmax(dim=1)
print(pred)
```
其中,`model(input)`会输出一个大小为`(1, num_classes)`的张量,每一行表示一张图片对应的各个类别的概率。`pred`是预测出来的类别,即概率最大的那个类别。
pytorch实现googlenet模型对C:\Users\14463\Desktop\指甲病数据\Nail Images目录下test和train两个文里的图片的自动识别与分类
PyTorch是一种基于Python的数据科学库,特别适用于深度学习。GoogLeNet(也称为Inception v1)是一个经典的卷积神经网络(CNN)架构,由Google开发,用于ImageNet图像分类挑战。要在C:\Users\14463\Desktop\Nail Images目录下的test和train文件夹中对图片进行自动识别和分类,你需要按照以下步骤操作:
1. **安装必要的库**:
确保已经安装了PyTorch、torchvision以及numpy等常用库。如果未安装,可以使用以下命令:
```bash
pip install torch torchvision numpy
```
2. **加载数据**:
使用`torchvision.datasets.ImageFolder`将目录结构转换为PyTorch可以处理的数据集。这里需要编写函数读取训练集和测试集:
```python
from torchvision import datasets, transforms
transform = transforms.Compose([
transforms.Resize((224, 224)), # 调整图片大小
transforms.ToTensor(),
transforms.Normalize(mean=[0.5, 0.5, 0.5], std=[0.5, 0.5, 0.5]) # 归一化
])
train_dataset = datasets.ImageFolder(root="C:\\Users\\14463\\Desktop\\Nail Images\\train", transform=transform)
test_dataset = datasets.ImageFolder(root="C:\\Users\\14463\\Desktop\\Nail Images\\test", transform=transform)
```
3. **数据预处理和分批**:
创建数据加载器以便从目录加载数据并按批次传递给模型:
```python
batch_size = 32
train_loader = torch.utils.data.DataLoader(train_dataset, batch_size=batch_size, shuffle=True)
test_loader = torch.utils.data.DataLoader(test_dataset, batch_size=batch_size, shuffle=False)
```
4. **构建GoogLeNet模型**:
导入预先定义好的模型,例如通过`torchvision.models.googlenet`:
```python
model = torchvision.models.googlenet(pretrained=True)
num_classes = len(train_dataset.classes) # 获取类别数
model.fc = nn.Linear(model.fc.in_features, num_classes) # 修改最后一层为适应任务
```
5. **训练与评估**:
定义损失函数(如交叉熵),优化器(如SGD或Adam),然后开始训练模型,并在测试集上评估性能:
```python
criterion = nn.CrossEntropyLoss()
optimizer = optim.SGD(model.parameters(), lr=0.001)
for epoch in range(num_epochs):
train_loss, _ = train_epoch(model, train_loader, criterion, optimizer)
test_loss, accuracy = test_epoch(model, test_loader, criterion)
print(f"Epoch {epoch+1}: Train Loss={train_loss:.4f}, Test Loss={test_loss:.4f}, Accuracy={accuracy*100:.2f}%")
```
6. **保存与预测**:
训练完成后,你可以选择保存模型以便将来使用:
```python
torch.save(model.state_dict(), "GoogLeNet_Nail_Disease.pth")
```
对新图片进行分类:
```python
model.eval() # 将模型置为评估模式
with torch.no_grad():
img = ... # 加载单张图片
pred = model(img.unsqueeze(0))
_, predicted_class = torch.max(pred.data, 1)
print(f"The image is classified as: {predicted_class.item()} class.")
```
记得替换上述代码中的`num_epochs`、`train_dataset.classes`、`img`等变量。完成这些步骤后,你就实现了GoogLeNet模型在指定目录下的图片识别和分类。
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