使用Python实现的CIFARNet算法进行图像分类
发布时间:2024-01-06 15:55:22
CIFARNet是一种基于深度学习的算法,用于在CIFAR-10数据集上进行图像分类。CIFAR-10数据集是一个包含10个分类的图像数据集,每个分类有6000张32x32的彩色图像。
下面是使用Python实现CIFARNet算法进行图像分类的示例:
首先,我们需要导入必要的库:
import torch import torch.nn as nn import torch.optim as optim import torchvision import torchvision.transforms as transforms
接下来,我们需要定义CIFARNet模型。这里我们使用一个简单的卷积神经网络作为模型:
class CIFARNet(nn.Module):
def __init__(self):
super(CIFARNet, self).__init__()
self.conv1 = nn.Conv2d(3, 32, kernel_size=5)
self.pool = nn.MaxPool2d(kernel_size=2, stride=2)
self.conv2 = nn.Conv2d(32, 64, kernel_size=5)
self.fc1 = nn.Linear(64 * 5 * 5, 512)
self.fc2 = nn.Linear(512, 10)
def forward(self, x):
x = self.pool(F.relu(self.conv1(x)))
x = self.pool(F.relu(self.conv2(x)))
x = x.view(-1, 64 * 5 * 5)
x = F.relu(self.fc1(x))
x = self.fc2(x)
return x
接下来,我们需要加载训练数据集和测试数据集,并对数据进行预处理:
transform = transforms.Compose(
[transforms.ToTensor(),
transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))])
trainset = torchvision.datasets.CIFAR10(root='./data', train=True,
download=True, transform=transform)
trainloader = torch.utils.data.DataLoader(trainset, batch_size=4,
shuffle=True, num_workers=2)
testset = torchvision.datasets.CIFAR10(root='./data', train=False,
download=True, transform=transform)
testloader = torch.utils.data.DataLoader(testset, batch_size=4,
shuffle=False, num_workers=2)
然后,我们可以创建CIFARNet模型的实例,选择合适的损失函数和优化器:
net = CIFARNet() criterion = nn.CrossEntropyLoss() optimizer = optim.SGD(net.parameters(), lr=0.001, momentum=0.9)
接下来,我们可以定义训练函数和测试函数:
def train(net, trainloader, criterion, optimizer, epochs):
for epoch in range(epochs):
running_loss = 0.0
for i, data in enumerate(trainloader, 0):
inputs, labels = data
optimizer.zero_grad()
outputs = net(inputs)
loss = criterion(outputs, labels)
loss.backward()
optimizer.step()
running_loss += loss.item()
if i % 2000 == 1999:
print('[%d, %5d] loss: %.3f' %
(epoch + 1, i + 1, running_loss / 2000))
running_loss = 0.0
def test(net, testloader):
correct = 0
total = 0
with torch.no_grad():
for data in testloader:
images, labels = data
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: %d %%' % (
100 * correct / total))
最后,我们可以调用训练函数和测试函数来训练和测试CIFARNet模型:
train(net, trainloader, criterion, optimizer, epochs=2) test(net, testloader)
通过执行上面的代码,我们可以使用CIFARNet算法对CIFAR-10数据集中的图像进行分类,并获得模型的准确率。
