手动顺序搭建resnet18

文件名:mode_resnet18

import torch

from torch import nn

# 导入记好了, 2维卷积,2维最大池化,展成1维,全连接层,构建网络结构辅助工具,2d网络归一化,激活函数,自适应平均池化

from torch.nn import Conv2d, MaxPool2d, Flatten, Linear, Sequential, BatchNorm2d, ReLU, AdaptiveAvgPool2d

from torchsummary import summary

class Resnet18(nn.Module):

def __init__(self, num_classes):

super(Resnet18, self).__init__()

self.model0 = Sequential(

# 0

# 输入3通道、输出64通道、卷积核大小、步长、补零、

Conv2d(in_channels=3, out_channels=64, kernel_size=(7, 7), stride=2, padding=3),

BatchNorm2d(64),

ReLU(),

MaxPool2d(kernel_size=(3, 3), stride=2, padding=1),

)

self.model1 = Sequential(

# 1.1

Conv2d(in_channels=64, out_channels=64, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(64),

ReLU(),

Conv2d(in_channels=64, out_channels=64, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(64),

ReLU(),

)

self.R1 = ReLU()

self.model2 = Sequential(

# 1.2

Conv2d(in_channels=64, out_channels=64, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(64),

ReLU(),

Conv2d(in_channels=64, out_channels=64, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(64),

ReLU(),

)

self.R2 = ReLU()

self.model3 = Sequential(

# 2.1

Conv2d(in_channels=64, out_channels=128, kernel_size=(3, 3), stride=2, padding=1),

BatchNorm2d(128),

ReLU(),

Conv2d(in_channels=128, out_channels=128, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(128),

ReLU(),

)

self.en1 = Sequential(

Conv2d(in_channels=64, out_channels=128, kernel_size=(1, 1), stride=2, padding=0),

BatchNorm2d(128),

ReLU(),

)

self.R3 = ReLU()

self.model4 = Sequential(

# 2.2

Conv2d(in_channels=128, out_channels=128, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(128),

ReLU(),

Conv2d(in_channels=128, out_channels=128, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(128),

ReLU(),

)

self.R4 = ReLU()

self.model5 = Sequential(

# 3.1

Conv2d(in_channels=128, out_channels=256, kernel_size=(3, 3), stride=2, padding=1),

BatchNorm2d(256),

ReLU(),

Conv2d(in_channels=256, out_channels=256, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(256),

ReLU(),

)

self.en2 = Sequential(

Conv2d(in_channels=128, out_channels=256, kernel_size=(1, 1), stride=2, padding=0),

BatchNorm2d(256),

ReLU(),

)

self.R5 = ReLU()

self.model6 = Sequential(

# 3.2

Conv2d(in_channels=256, out_channels=256, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(256),

ReLU(),

Conv2d(in_channels=256, out_channels=256, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(256),

ReLU(),

)

self.R6 = ReLU()

self.model7 = Sequential(

# 4.1

Conv2d(in_channels=256, out_channels=512, kernel_size=(3, 3), stride=2, padding=1),

BatchNorm2d(512),

ReLU(),

Conv2d(in_channels=512, out_channels=512, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(512),

ReLU(),

)

self.en3 = Sequential(

Conv2d(in_channels=256, out_channels=512, kernel_size=(1, 1), stride=2, padding=0),

BatchNorm2d(512),

ReLU(),

)

self.R7 = ReLU()

self.model8 = Sequential(

# 4.2

Conv2d(in_channels=512, out_channels=512, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(512),

ReLU(),

Conv2d(in_channels=512, out_channels=512, kernel_size=(3, 3), stride=1, padding=1),

BatchNorm2d(512),

ReLU(),

)

self.R8 = ReLU()

# AAP 自适应平均池化

self.aap = AdaptiveAvgPool2d((1, 1))

# flatten 维度展平

self.flatten = Flatten(start_dim=1)

# FC 全连接层

self.fc = Linear(512, num_classes)

def forward(self, x):

x = self.model0(x)

f1 = x

x = self.model1(x)

x = x + f1

x = self.R1(x)

f1_1 = x

x = self.model2(x)

x = x + f1_1

x = self.R2(x)

f2_1 = x

f2_1 = self.en1(f2_1)

x = self.model3(x)

x = x + f2_1

x = self.R3(x)

f2_2 = x

x = self.model4(x)

x = x + f2_2

x = self.R4(x)

f3_1 = x

f3_1 = self.en2(f3_1)

x = self.model5(x)

x = x + f3_1

x = self.R5(x)

f3_2 = x

x = self.model6(x)

x = x + f3_2

x = self.R6(x)

f4_1 = x

f4_1 = self.en3(f4_1)

x = self.model7(x)

x = x + f4_1

x = self.R7(x)

f4_2 = x

x = self.model8(x)

x = x + f4_2

x = self.R8(x)

# 最后3个

x = self.aap(x)

x = self.flatten(x)

x = self.fc(x)

return x

if __name__ == '__main__':

# 10分类

res18 = Resnet18(10).to('cuda:0')

summary(res18, (3, 224, 224))

10分类训练代码

import torch

import torchvision

from torch import nn

from torch.utils.data import DataLoader

# from torch.utils.tensorboard import SummaryWriter

from mode_resnet18 import Resnet18

# 使用GPU: 需要添加的地方-->模型--损失函数-- .to(device)

# 使用第 0 个GPU, 判断语句,能使用GPU则使用。

device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")

# 加载数据

# 参数:下载保存路径、train=训练集(True)或者测试集(False)、download=在线(True) 或者 本地(False)、数据类型转换

train_data = torchvision.datasets.CIFAR10("./dataset",

train=True,

download=True,

transform=torchvision.transforms.ToTensor())

test_data = torchvision.datasets.CIFAR10("./dataset",

train=False,

download=True,

transform=torchvision.transforms.ToTensor())

train_len = len(train_data)

val_len = len(test_data)

print("训练数据集合{} = 50000".format(train_len))

print("测试数据集合{} = 10000".format(val_len))

# 格式打包

# 参数:数据、1组几个、下一轮轮是否打乱、进程个数、最后一组是否凑成一组

train_loader = DataLoader(dataset=train_data, batch_size=2, shuffle=True, num_workers=0, drop_last=True)

test_loader = DataLoader(dataset=test_data, batch_size=2, shuffle=True, num_workers=0, drop_last=True)

# 导入网络

tudui = Resnet18(10)

# 使用GPU

tudui = tudui.to(device)

# 损失函数

loss_fn = nn.CrossEntropyLoss()

# 使用GPU

loss_fn = loss_fn.to(device)

# 优化器

# 学习率

learning_rate = 1e-4

optimizer = torch.optim.SGD(tudui.parameters(), lr=learning_rate)

# 记录训练次数

train = 0

# 记录测试次数

val = 0

# 训练轮数

epoch = 1000

# writer = SummaryWriter("logs")

for i in range(epoch):

print()

print("第{}轮训练开始".format(i + 1))

# 训练开关-->针对与过拟合的操作层才有效,例如:Dropout,BatchNorm,etc等

tudui.train(mode=True)

# 准确率总和

acc_ = 0

# 训练

for data in train_loader:

imgs, targets = data

# 使用GPU

imgs = imgs.to(device)

targets = targets.to(device)

# 数据输入模型

outputs = tudui(imgs)

loss = loss_fn(outputs, targets)

# 优化模型 清零、反向传播、优化器开始优化

optimizer.zero_grad()

loss.backward()

optimizer.step()

# 累计训练次数

train += 1

# loss现在看不出来,但应该加 loss.item() 这可让其直接显示数值

print("\r训练次数:{},Loss:{}".format(train, loss), end="")

# 准确率

accuracy = (outputs.argmax(1) == targets).sum()

acc_ += accuracy

if train % 4000 == 0:

print("训练次数:{},Loss:{}".format(train, loss))

# writer.add_scalar("train", loss, train)

print()

print("Loss:{}, 准确率:{}".format(loss, acc_/train_len))

# 测试开关

tudui.eval()

# 测试

total_test_loss = 0

acc_val = 0

with torch.no_grad():

for data in test_loader:

imgs, targets = data

# 使用GPU

imgs = imgs.to(device)

targets = targets.to(device)

outputs = tudui(imgs)

loss = loss_fn(outputs, targets)

# 准确率

accuracy_val = (outputs.argmax(1) == targets).sum()

acc_val += accuracy_val

total_test_loss += loss

print("\r测试集的Loss:{}".format(total_test_loss), end="")

print()

print("整体测试集的Loss:{}, 准确率{}".format(total_test_loss, acc_val/val_len))

# writer.add_scalar("val", loss, val)

val += 1

# 每轮保存模型

torch.save(tudui, "tudui_{}.pth".format(i))

print("模型已保存")

# writer.close()

测试代码

去网上随便下载一张图

import torchvision

from resnaet_18.a2 import Resnet18

import torch

from PIL import Image

# 读取图像

img = Image.open("9.jpg")

# 数据预处理

# 缩放

transform = torchvision.transforms.Compose([torchvision.transforms.Resize((32, 32)),

torchvision.transforms.ToTensor()])

image = transform(img)

print(image.shape)

# 根据保存方式加载

model = torch.load("tudui_38.pth", map_location=torch.device('cpu'))

# 注意维度转换,单张图片

image1 = torch.reshape(image, (1, 3, 32, 32))

# 测试开关

model.eval()

# 节约性能

with torch.no_grad():

output = model(image1)

print(output)

# print(output.argmax(1))

# 定义类别对应字典

dist = {0: "飞机", 1: "汽车", 2: "鸟", 3: "猫", 4: "鹿", 5: "狗", 6: "青蛙", 7: "马", 8: "船", 9: "卡车"}

# 转numpy格式,列表内取第一个

a = dist[output.argmax(1).numpy()[0]]

img.show()

print(a)

精彩文章

评论可见,请评论后查看内容,谢谢!!!
 您阅读本篇文章共花了: