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使用Python实现CIFARNet()模型进行图像标签预测的实验研究

发布时间:2023-12-15 09:27:55

CIFARNet是一个经典的卷积神经网络模型,用于对CIFAR-10数据集中的图像进行分类预测。下面我将介绍如何使用Python实现CIFARNet模型,并进行图像标签预测的实验研究。

首先,我们需要导入必要的库和模块:

import torch
import torch.nn as nn
import torch.optim as optim
import torchvision
import torchvision.transforms as transforms

接下来,我们可以定义CIFARNet模型的结构。CIFARNet模型由多个卷积层、池化层和全连接层组成。这里我们使用了3个卷积层和2个全连接层。下面是CIFARNet模型的定义:

class CIFARNet(nn.Module):
    def __init__(self, num_classes=10):
        super(CIFARNet, self).__init__()
        self.conv1 = nn.Conv2d(3, 32, kernel_size=3, padding=1)
        self.conv2 = nn.Conv2d(32, 64, kernel_size=3, padding=1)
        self.conv3 = nn.Conv2d(64, 128, kernel_size=3, padding=1)
        self.pool = nn.MaxPool2d(kernel_size=2, stride=2)
        self.fc1 = nn.Linear(128 * 4 * 4, 512)
        self.fc2 = nn.Linear(512, num_classes)

    def forward(self, x):
        x = self.pool(F.relu(self.conv1(x)))
        x = self.pool(F.relu(self.conv2(x)))
        x = self.pool(F.relu(self.conv3(x)))
        x = x.view(-1, 128 * 4 * 4)
        x = F.relu(self.fc1(x))
        x = self.fc2(x)
        return x

然后,我们可以对CIFAR-10数据集进行预处理。这里我们使用torchvision中的transform模块来进行数据预处理,包括数据归一化和数据增强,以提高模型的性能。

transform_train = transforms.Compose([
    transforms.RandomCrop(32, padding=4),
    transforms.RandomHorizontalFlip(),
    transforms.ToTensor(),
    transforms.Normalize(mean=[0.5, 0.5, 0.5], std=[0.5, 0.5, 0.5])
])

transform_test = transforms.Compose([
    transforms.ToTensor(),
    transforms.Normalize(mean=[0.5, 0.5, 0.5], std=[0.5, 0.5, 0.5])
])

trainset = torchvision.datasets.CIFAR10(root='./data', train=True,
                                        download=True, transform=transform_train)

testset = torchvision.datasets.CIFAR10(root='./data', train=False,
                                       download=True, transform=transform_test)

trainloader = torch.utils.data.DataLoader(trainset, batch_size=128,
                                          shuffle=True, num_workers=2)

testloader = torch.utils.data.DataLoader(testset, batch_size=128,
                                         shuffle=False, num_workers=2)

classes = ('plane', 'car', 'bird', 'cat',
           'deer', 'dog', 'frog', 'horse', 'ship', 'truck')

接下来,我们可以定义优化器和损失函数:

net = CIFARNet()
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
net = net.to(device)
criterion = nn.CrossEntropyLoss()
optimizer = optim.SGD(net.parameters(), lr=0.01, momentum=0.9)

然后,我们可以进行模型的训练和测试:

def train(net, criterion, optimizer, trainloader, num_epochs):
    for epoch in range(num_epochs):
        running_loss = 0.0
        for i, data in enumerate(trainloader, 0):
            inputs, labels = data
            inputs, labels = inputs.to(device), labels.to(device)
            optimizer.zero_grad()
            outputs = net(inputs)
            loss = criterion(outputs, labels)
            loss.backward()
            optimizer.step()
            running_loss += loss.item()
            if i % 100 == 99:
                print('[%d, %5d] loss: %.3f' % (epoch + 1, i + 1, running_loss / 100))
                running_loss = 0.0

def test(net, testloader):
    correct = 0
    total = 0
    with torch.no_grad():
        for data in testloader:
            images, labels = data
            images, labels = images.to(device), labels.to(device)
            outputs = net(images)
            _, predicted = torch.max(outputs.data, 1)
            total += labels.size(0)
            correct += (predicted == labels).sum().item()
    print('Accuracy of the network on the 10000 test images: %.2f %%' % (100 * correct / total))

num_epochs = 10
train(net, criterion, optimizer, trainloader, num_epochs)
test(net, testloader)

以上就是使用Python实现CIFARNet模型进行图像标签预测的实验研究的示例。通过对CIFAR-10数据集的训练和测试,我们可以得到模型在测试集上的准确率。你也可以尝试调整模型的超参数和训练参数,以获取更好的性能。