CNN進階 | 關於Inception Module與 Residual network | MNIST資料集
阿新 • • 發佈:2022-05-30
1. 關於GoogleNet:
2. Inception Module
3. 1*1 Convolution:
為什麼使用1*1的卷積:
節省訓練時間
4. Inception Module 的實現
程式碼:
import torch import torch.nn as nn from torchvision import transforms from torchvision import datasets from torch.utils.data import DataLoader import torch.nn.functional as F import torch.optim as optim # prepare dataset batch_size = 64 transform = transforms.Compose([transforms.ToTensor(), transforms.Normalize((0.1307,), (0.3081,))]) # 歸一化,均值和方差 train_dataset = datasets.MNIST(root='./dataset/mnist/', train=True, download=False, transform=transform) train_loader = DataLoader(train_dataset, shuffle=True, batch_size=batch_size) test_dataset = datasets.MNIST(root='./dataset/mnist/', train=False, download=False, transform=transform) test_loader = DataLoader(test_dataset, shuffle=False, batch_size=batch_size) # design model using class class InceptionA(nn.Module): def __init__(self, in_channels): super(InceptionA, self).__init__() self.branch1x1 = nn.Conv2d(in_channels, 16, kernel_size=1) self.branch5x5_1 = nn.Conv2d(in_channels, 16, kernel_size=1) self.branch5x5_2 = nn.Conv2d(16, 24, kernel_size=5, padding=2) self.branch3x3_1 = nn.Conv2d(in_channels, 16, kernel_size=1) self.branch3x3_2 = nn.Conv2d(16, 24, kernel_size=3, padding=1) self.branch3x3_3 = nn.Conv2d(24, 24, kernel_size=3, padding=1) self.branch_pool = nn.Conv2d(in_channels, 24, kernel_size=1) def forward(self, x): branch1x1 = self.branch1x1(x) branch5x5 = self.branch5x5_1(x) branch5x5 = self.branch5x5_2(branch5x5) branch3x3 = self.branch3x3_1(x) branch3x3 = self.branch3x3_2(branch3x3) branch3x3 = self.branch3x3_3(branch3x3) branch_pool = F.avg_pool2d(x, kernel_size=3, stride=1, padding=1) branch_pool = self.branch_pool(branch_pool) outputs = [branch1x1, branch5x5, branch3x3, branch_pool] return torch.cat(outputs, dim=1) # b,c,w,h c對應的是dim=1 class Net(nn.Module): def __init__(self): super(Net, self).__init__() self.conv1 = nn.Conv2d(1, 10, kernel_size=5) self.conv2 = nn.Conv2d(88, 20, kernel_size=5) # 88 = 24x3 + 16 self.incep1 = InceptionA(in_channels=10) # 與conv1 中的10對應 self.incep2 = InceptionA(in_channels=20) # 與conv2 中的20對應 self.mp = nn.MaxPool2d(2) self.fc = nn.Linear(1408, 10) def forward(self, x): in_size = x.size(0) x = F.relu(self.mp(self.conv1(x))) x = self.incep1(x) x = F.relu(self.mp(self.conv2(x))) x = self.incep2(x) x = x.view(in_size, -1) x = self.fc(x) return x model = Net() # construct loss and optimizer criterion = torch.nn.CrossEntropyLoss() optimizer = optim.SGD(model.parameters(), lr=0.01, momentum=0.5) # training cycle forward, backward, update def train(epoch): running_loss = 0.0 for batch_idx, data in enumerate(train_loader, 0): inputs, target = data optimizer.zero_grad() outputs = model(inputs) loss = criterion(outputs, target) loss.backward() optimizer.step() running_loss += loss.item() if batch_idx % 300 == 299: print('[%d, %5d] loss: %.3f' % (epoch + 1, batch_idx + 1, running_loss / 300)) running_loss = 0.0 def test(): correct = 0 total = 0 with torch.no_grad(): for data in test_loader: images, labels = data outputs = model(images) _, predicted = torch.max(outputs.data, dim=1) total += labels.size(0) correct += (predicted == labels).sum().item() print('accuracy on test set: %d %% ' % (100 * correct / total)) if __name__ == '__main__': for epoch in range(10): train(epoch) test()
[1, 300] loss: 0.931 [1, 600] loss: 0.190 [1, 900] loss: 0.129 accuracy on test set: 97 % [2, 300] loss: 0.105 [2, 600] loss: 0.088 [2, 900] loss: 0.083 accuracy on test set: 97 % [3, 300] loss: 0.074 [3, 600] loss: 0.074 [3, 900] loss: 0.066 accuracy on test set: 98 % [4, 300] loss: 0.063 [4, 600] loss: 0.062 [4, 900] loss: 0.055 accuracy on test set: 98 % [5, 300] loss: 0.058 [5, 600] loss: 0.052 [5, 900] loss: 0.052 accuracy on test set: 98 % [6, 300] loss: 0.047 [6, 600] loss: 0.051 [6, 900] loss: 0.047 accuracy on test set: 98 % [7, 300] loss: 0.044 [7, 600] loss: 0.043 [7, 900] loss: 0.043 accuracy on test set: 98 % [8, 300] loss: 0.041 [8, 600] loss: 0.041 [8, 900] loss: 0.039 accuracy on test set: 98 % [9, 300] loss: 0.033 [9, 600] loss: 0.039 [9, 900] loss: 0.038 accuracy on test set: 98 % [10, 300] loss: 0.033 [10, 600] loss: 0.039 [10, 900] loss: 0.031 accuracy on test set: 98 %
5. 執行結果:
6. 關於梯度消失:
7. 關於Residual network
8. Residual network的實現
程式碼:
import torch import torch.nn as nn from torchvision import transforms from torchvision import datasets from torch.utils.data import DataLoader import torch.nn.functional as F import torch.optim as optim # prepare dataset batch_size = 64 transform = transforms.Compose([transforms.ToTensor(), transforms.Normalize((0.1307,), (0.3081,))]) # 歸一化,均值和方差 train_dataset = datasets.MNIST(root='./dataset/mnist/', train=True, download=False, transform=transform) train_loader = DataLoader(train_dataset, shuffle=True, batch_size=batch_size) test_dataset = datasets.MNIST(root='./dataset/mnist/', train=False, download=False, transform=transform) test_loader = DataLoader(test_dataset, shuffle=False, batch_size=batch_size) # design model using class class ResidualBlock(nn.Module): def __init__(self, channels): super(ResidualBlock, self).__init__() self.channels = channels self.conv1 = nn.Conv2d(channels, channels, kernel_size=3, padding=1) self.conv2 = nn.Conv2d(channels, channels, kernel_size=3, padding=1) def forward(self, x): y = F.relu(self.conv1(x)) y = self.conv2(y) return F.relu(x + y) class Net(nn.Module): def __init__(self): super(Net, self).__init__() self.conv1 = nn.Conv2d(1, 16, kernel_size=5) self.conv2 = nn.Conv2d(16, 32, kernel_size=5) # 88 = 24x3 + 16 self.rblock1 = ResidualBlock(16) self.rblock2 = ResidualBlock(32) self.mp = nn.MaxPool2d(2) self.fc = nn.Linear(512, 10) # 暫時不知道1408咋能自動出來的 def forward(self, x): in_size = x.size(0) x = self.mp(F.relu(self.conv1(x))) x = self.rblock1(x) x = self.mp(F.relu(self.conv2(x))) x = self.rblock2(x) x = x.view(in_size, -1) x = self.fc(x) return x model = Net() # construct loss and optimizer criterion = torch.nn.CrossEntropyLoss() optimizer = optim.SGD(model.parameters(), lr=0.01, momentum=0.5) # training cycle forward, backward, update def train(epoch): running_loss = 0.0 for batch_idx, data in enumerate(train_loader, 0): inputs, target = data optimizer.zero_grad() outputs = model(inputs) loss = criterion(outputs, target) loss.backward() optimizer.step() running_loss += loss.item() if batch_idx % 300 == 299: print('[%d, %5d] loss: %.3f' % (epoch+1, batch_idx+1, running_loss/300)) running_loss = 0.0 def test(): correct = 0 total = 0 with torch.no_grad(): for data in test_loader: images, labels = data outputs = model(images) _, predicted = torch.max(outputs.data, dim=1) total += labels.size(0) correct += (predicted == labels).sum().item() print('accuracy on test set: %d %% ' % (100*correct/total)) if __name__ == '__main__': for epoch in range(10): train(epoch) test()
[1, 300] loss: 0.543
[1, 600] loss: 0.145
[1, 900] loss: 0.123
accuracy on test set: 97 %
[2, 300] loss: 0.089
[2, 600] loss: 0.080
[2, 900] loss: 0.067
accuracy on test set: 97 %
[3, 300] loss: 0.058
[3, 600] loss: 0.057
[3, 900] loss: 0.054
accuracy on test set: 98 %
[4, 300] loss: 0.045
[4, 600] loss: 0.047
[4, 900] loss: 0.047
accuracy on test set: 98 %
[5, 300] loss: 0.038
[5, 600] loss: 0.040
[5, 900] loss: 0.038
accuracy on test set: 98 %
[6, 300] loss: 0.033
[6, 600] loss: 0.036
[6, 900] loss: 0.031
accuracy on test set: 98 %
[7, 300] loss: 0.027
[7, 600] loss: 0.032
[7, 900] loss: 0.028
accuracy on test set: 98 %
[8, 300] loss: 0.028
[8, 600] loss: 0.025
[8, 900] loss: 0.027
accuracy on test set: 98 %
[9, 300] loss: 0.020
[9, 600] loss: 0.025
[9, 900] loss: 0.024
accuracy on test set: 98 %
[10, 300] loss: 0.021
[10, 600] loss: 0.024
[10, 900] loss: 0.020
accuracy on test set: 99 %