Pytorch入门下 —— 其他

发布时间:2022-06-28 发布网站:脚本宝典
脚本宝典收集整理的这篇文章主要介绍了Pytorch入门下 —— 其他脚本宝典觉得挺不错的,现在分享给大家,也给大家做个参考。

本节内容参照小土堆的pytorch入门视频教程。

现有模型使用和修改

pytorch框架提供了很多现有模型,其中torchvision.models包中有很多关于视觉(图像)领域的模型,如下图:

Pytorch入门下 —— 其他

下面以VGG16为例讲解如何使用以及更改现有模型:

Pytorch入门下 —— 其他

PRetrainedTrue,返回在ImageNet上预训练过的模型;pregressTrue在下载模型时会通过标准错误流输出进度条。

创建如下脚本并运行:

From torchvision import models


# 创建预训练过的模型,并输出进度
vgg16_pretrained = models.vgg16(pretrained=True, progress=True)
# 创建没训练过的模型,不输出进度
vgg16 = models.vgg16(pretrained=False, progress=False)

# 控制台输出模型结构
print(vgg16_pretrained)

控制台输出如下:

Downloading: "https://download.pytorch.org/models/vgg16-397923af.pth" to C:Userswinlsr/.cachetorchhubcheckpointsvgg16-397923af.pth
100.0%
VGG(
  (features): Sequential(
    (0): Conv2d(3, 64, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (1): ReLU(inplace=True)
    (2): Conv2d(64, 64, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (3): ReLU(inplace=True)
    (4): Maxpool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (5): Conv2d(64, 128, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (6): ReLU(inplace=True)
    (7): Conv2d(128, 128, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (8): ReLU(inplace=True)
    (9): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (10): Conv2d(128, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (11): ReLU(inplace=True)
    (12): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (13): ReLU(inplace=True)
    (14): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (15): ReLU(inplace=True)
    (16): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (17): Conv2d(256, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (18): ReLU(inplace=True)
    (19): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (20): ReLU(inplace=True)
    (21): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (22): ReLU(inplace=True)
    (23): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (24): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (25): ReLU(inplace=True)
    (26): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (27): ReLU(inplace=True)
    (28): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (29): ReLU(inplace=True)
    (30): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
  )
  (avgpool): AdaptiveAvgPool2d(output_size=(7, 7))
  (classifier): Sequential(
    (0): Linear(in_features=25088, out_features=4096, bias=True)
    (1): ReLU(inplace=True)
    (2): Dropout(p=0.5, inplace=False)
    (3): Linear(in_features=4096, out_features=4096, bias=True)
    (4): ReLU(inplace=True)
    (5): Dropout(p=0.5, inplace=False)
    (6): Linear(in_features=4096, out_features=1000, bias=True)
  )
)

如上输出中的的VGG表示模型的class名,featuresVGG含有的一个Sequential组件(Module),avgpoolAdaptiveAvgPool2d组件,classifier同样为Sequential组件。

创建如下脚本并运行:

from torchvision import models
from torch import nn


# 创建预训练过的模型,并输出进度
vgg16_pretrained = models.vgg16(pretrained=True, progress=True)
# 创建没训练过的模型,不输出进度
vgg16 = models.vgg16(pretrained=False, progress=False)

# 给vgg添加一个线性Module(层)
vgg16_pretrained.add_module("linear", nn.Linear(1000, 10))

# 控制台输出模型结构
print(vgg16_pretrained)

输出如下:

VGG(
  (features): Sequential(
    (0): Conv2d(3, 64, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (1): ReLU(inplace=True)
    (2): Conv2d(64, 64, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (3): ReLU(inplace=True)
    (4): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (5): Conv2d(64, 128, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (6): ReLU(inplace=True)
    (7): Conv2d(128, 128, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (8): ReLU(inplace=True)
    (9): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (10): Conv2d(128, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (11): ReLU(inplace=True)
    (12): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (13): ReLU(inplace=True)
    (14): Conv2d(256, 256, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (15): ReLU(inplace=True)
    (16): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (17): Conv2d(256, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (18): ReLU(inplace=True)
    (19): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (20): ReLU(inplace=True)
    (21): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (22): ReLU(inplace=True)
    (23): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (24): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (25): ReLU(inplace=True)
    (26): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (27): ReLU(inplace=True)
    (28): Conv2d(512, 512, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
    (29): ReLU(inplace=True)
    (30): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
  )
  (avgpool): AdaptiveAvgPool2d(output_size=(7, 7))
  (classifier): Sequential(
    (0): Linear(in_features=25088, out_features=4096, bias=True)
    (1): ReLU(inplace=True)
    (2): Dropout(p=0.5, inplace=False)
    (3): Linear(in_features=4096, out_features=4096, bias=True)
    (4): ReLU(inplace=True)
    (5): Dropout(p=0.5, inplace=False)
    (6): Linear(in_features=4096, out_features=1000, bias=True)
  )
  (linear): Linear(in_features=1000, out_features=10, bias=True) # 添加成功
)

创建如下脚本并运行:

from torchvision import models
from torch import nn


# 创建预训练过的模型,并输出进度
vgg16_pretrained = models.vgg16(pretrained=True, progress=True)
# 创建没训练过的模型,不输出进度
vgg16 = models.vgg16(pretrained=False, progress=False)

# 删除 features 组件
del vgg16_pretrained.features
# 在 classifier 组件中添加组件
vgg16_pretrained.classifier.add_module("7", nn.Linear(1000, 10))
# 修改 classifier 组件中的第1个组件为 softmax(0开始)
vgg16_pretrained.classifier[1] = nn.Softmax()

# 控制台输出模型结构
print(vgg16_pretrained)

输出如下:

VGG(
  # 删除features成功
  (avgpool): AdaptiveAvgPool2d(output_size=(7, 7))
  (classifier): Sequential(
    (0): Linear(in_features=25088, out_features=4096, bias=True)
    # 修改为softmax成功
    (1): Softmax(dim=None)
    (2): Dropout(p=0.5, inplace=False)
    (3): Linear(in_features=4096, out_features=4096, bias=True)
    (4): ReLU(inplace=True)
    (5): Dropout(p=0.5, inplace=False)
    (6): Linear(in_features=4096, out_features=1000, bias=True)
    # 添加成功
    (7): Linear(in_features=1000, out_features=10, bias=True)
  )
)

模型的保存与读取

pytorch中有两种模型保存和读取方式:

执行如下脚本:

from _07_cifar10_model.cifar10_model import MyModel
import torch

cifar10_model = MyModel()

# 方式1:保存 模型 + 参数
torch.save(cifar10_model, "cifar10_model.pth")
# 方式2:只保存 参数(官方推荐)
torch.save(cifar10_model.state_dict(), "cifar10_model_state_dict.pth")

执行成功后,脚本文件所在目录会生成:cifar10_model.pthcifar10_model_state_dict.pth两个文件。

恢复方式1保存的模型:

import torch

# 方式1
cifar10_model = torch.load("cifar10_model.pth")
print(cifar10_model)

输出如下:

MyModel(
  (model): Sequential(
    (0): Conv2d(3, 32, kernel_size=(5, 5), stride=(1, 1), padding=(2, 2))
    (1): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (2): Conv2d(32, 32, kernel_size=(5, 5), stride=(1, 1), padding=(2, 2))
    (3): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (4): Conv2d(32, 64, kernel_size=(5, 5), stride=(1, 1), padding=(2, 2))
    (5): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (6): Flatten(start_dim=1, end_dim=-1)
    (7): Linear(in_features=1024, out_features=64, bias=True)
    (8): Linear(in_features=64, out_features=10, bias=True)
  )
)

恢复方式2保存的模型(官方推荐):

import torch
from _07_cifar10_model.cifar10_model import MyModel

# 方式2(官方推荐)
cifar10_model = MyModel()
cifar10_model.load_state_dict(torch.load("cifar10_model_state_dict.pth"))
print(cifar10_model)

输出如下:

MyModel(
  (model): Sequential(
    (0): Conv2d(3, 32, kernel_size=(5, 5), stride=(1, 1), padding=(2, 2))
    (1): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (2): Conv2d(32, 32, kernel_size=(5, 5), stride=(1, 1), padding=(2, 2))
    (3): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (4): Conv2d(32, 64, kernel_size=(5, 5), stride=(1, 1), padding=(2, 2))
    (5): MaxPool2d(kernel_size=2, stride=2, padding=0, dilation=1, ceil_mode=False)
    (6): Flatten(start_dim=1, end_dim=-1)
    (7): Linear(in_features=1024, out_features=64, bias=True)
    (8): Linear(in_features=64, out_features=10, bias=True)
  )
)

模型的完整训练套路

前面我们虽然搭建了在CIFAR10数据集上的分类模型,但是我们并没有对模型进行完整的训练。下面会对我们的模型进行一个完整的训练。训练代码如下:

import time
from torch.utils import tensorboard
from torch.utils.data import DataLoader
from _07_cifar10_model.cifar10_model import MyModel
import torchvision
import torch.nn

if __name__ == "__main__":
    start_time = time.time()
    # 准备训练数据集和测试数据集
    transform = torchvision.transforms.COMpose({
        torchvision.transforms.ToTensor()
    })
    train_data = torchvision.datasets.CIFAR10("./dataset", train=True,
                                              transform=transform,
                                              download=True)
    test_data = torchvision.datasets.CIFAR10("./dataset", train=False,
                                             transform=transform,
                                             download=True)
    train_data_len = len(train_data)
    test_data_len = len(test_data)
    print("训练集的长度: {}".format(train_data_len))
    print("测试集的长度: {}".format(test_data_len))

    # 创建训练集和测试集的dataloader
    train_dataloader = DataLoader(dataset=train_data, batch_size=64,
                                  shuffle=True,
                                  num_workers=16)
    test_dataloader = DataLoader(dataset=test_data, batch_size=64,
                                 shuffle=True,
                                 num_workers=16)

    # 创建网络
    cifar10_model = MyModel()

    # 创建损失函数
    loss_func = torch.nn.CrossEntropyLoss()

    # 创建优化器
    # 学习率,科学计数的形式方便改动
    learning_rate = 1e-2
    optimizer = torch.optim.SGD(cifar10_model.parameters(), lr=learning_rate)

    # 训练次数
    total_train_step = 0
    # 训练轮次
    epoch = 20

    # 创建 tensorboard SummaryWrITer
    writer = tensorboard.SummaryWriter("LOGs")

    for i in range(epoch):
        print("----------第 {} 轮训练开始-----------".format(i))

        # 模型进入训练模式,该方法在当前模型可有可无(加上是个@R_406_2752@)
        cifar10_model.train()
        for data in train_dataloader:
            images, targets = data
            outputs = cifar10_model(images)
            loss = loss_func(outputs, targets)

            # 清空上一轮计算的梯度
            optimizer.zero_grad()
            # 反向传播计算梯度
            loss.backward()
            # 优化器优化参数(执行梯度下降)
            optimizer.step()

            total_train_step += 1
            writer.add_scalar("train/Loss", loss.item(), total_train_step)
            if total_train_step % 100 == 0:
                print("训练次数: {}, Loss: {}".
                      format(total_train_step, loss.item()))

        total_test_loss = 0.0
        total_accuracy = 0.0
        # 每轮 epoch 后计算模型在测试集上的loss表现
        # 测试时无需计算梯度,可加快计算速度
        # 模型进入验证(测试)模式,该方法在当前模型可有可无(加上是个好习惯)
        cifar10_model.eval()
        with torch.no_grad():
            for data in test_dataloader:
                images, targets = data
                outputs = cifar10_model(images)
                loss = loss_func(outputs, targets)

                total_test_loss += loss.item()

                accuracy = (outputs.argmax(1) == targets).sum()
                total_accuracy += accuracy
            print("测试准确率:{}".format(total_accuracy/test_data_len))
            writer.add_scalar("test/Loss", total_test_loss, i)
            writer.add_scalar("test/accuracy", total_accuracy/test_data_len, i)

        # 保存每轮训练后的模型
        torch.save(cifar10_model.state_dict(),
                   "cifar10_model_state_dict_{}_epoch.pth".format(i))

    writer.close()

    end_time = time.time()
    print("耗时:{}".format(end_time - start_time))

如上代码中调用模型的train()eval()方法主要是对模型中的DropoutBatchNormModule有用(如果存在),官方解释如下:

Pytorch入门下 —— 其他

Pytorch入门下 —— 其他

tensorboard可视化结果如下:

Pytorch入门下 —— 其他

利用GPU训练

没有GPU同学可以想办法使用GOOGLE colab,他提供了免费的GPU使用时长,使用起来和jupyter noteBook很像。

利用GPU训练很简单

方式一:.cuda()

只需要对 网络模型、数据(输入、标注)、损失函数调用.cuda()方法:

import time
from torch.utils import tensorboard
from torch.utils.data import DataLoader
from _07_cifar10_model.cifar10_model import MyModel
import torchvision
import torch.nn

if __name__ == "__main__":
    start_time = time.time()
    # 准备训练数据集和测试数据集
    transform = torchvision.transforms.Compose({
        torchvision.transforms.ToTensor()
    })
    train_data = torchvision.datasets.CIFAR10("./dataset", train=True,
                                              transform=transform,
                                              download=True)
    test_data = torchvision.datasets.CIFAR10("./dataset", train=False,
                                             transform=transform,
                                             download=True)
    train_data_len = len(train_data)
    test_data_len = len(test_data)
    print("训练集的长度: {}".format(train_data_len))
    print("测试集的长度: {}".format(test_data_len))

    # 创建训练集和测试集的dataloader
    train_dataloader = DataLoader(dataset=train_data, batch_size=64,
                                  shuffle=True,
                                  num_workers=16)
    test_dataloader = DataLoader(dataset=test_data, batch_size=64,
                                 shuffle=True,
                                 num_workers=16)

    # 创建网络
    cifar10_model = MyModel()
    if torch.cuda.is_available():
        cifar10_model = cifar10_model.cuda()

    # 创建损失函数
    loss_func = torch.nn.CrossEntropyLoss()
    if torch.cuda.is_available():
        loss_func = loss_func.cuda()

    # 创建优化器
    # 学习率,科学计数的形式方便改动
    learning_rate = 1e-2
    optimizer = torch.optim.SGD(cifar10_model.parameters(), lr=learning_rate)

    # 训练次数
    total_train_step = 0
    # 训练轮次
    epoch = 20

    # 创建 tensorboard SummaryWriter
    writer = tensorboard.SummaryWriter("logs")

    for i in range(epoch):
        print("----------第 {} 轮训练开始-----------".format(i))

        # 模型进入训练模式,该方法在当前模型可有可无(加上是个好习惯)
        cifar10_model.train()
        for data in train_dataloader:
            images, targets = data

            if torch.cuda.is_available():
                images = images.cuda()
                targets = targets.cuda()

            outputs = cifar10_model(images)
            loss = loss_func(outputs, targets)

            # 清空上一轮计算的梯度
            optimizer.zero_grad()
            # 反向传播计算梯度
            loss.backward()
            # 优化器优化参数(执行梯度下降)
            optimizer.step()

            total_train_step += 1
            writer.add_scalar("train/Loss", loss.item(), total_train_step)
            if total_train_step % 100 == 0:
                print("训练次数: {}, Loss: {}".
                      format(total_train_step, loss.item()))

        total_test_loss = 0.0
        total_accuracy = 0.0
        # 每轮 epoch 后计算模型在测试集上的loss表现
        # 测试时无需计算梯度,可加快计算速度
        # 模型进入验证(测试)模式,该方法在当前模型可有可无(加上是个好习惯)
        cifar10_model.eval()
        with torch.no_grad():
            for data in test_dataloader:
                images, targets = data

                if torch.cuda.is_available():
                    images = images.cuda()
                    targets = targets.cuda()

                outputs = cifar10_model(images)
                loss = loss_func(outputs, targets)

                total_test_loss += loss.item()

                accuracy = (outputs.argmax(1) == targets).sum()
                total_accuracy += accuracy
            print("测试准确率:{}".format(total_accuracy/test_data_len))
            writer.add_scalar("test/Loss", total_test_loss, i)
            writer.add_scalar("test/accuracy", total_accuracy/test_data_len, i)

        # 保存每轮训练后的模型
        torch.save(cifar10_model.state_dict(),
                   "cifar10_model_state_dict_{}_epoch.pth".format(i))

    writer.close()

    end_time = time.time()
    print("耗时:{}".format(end_time - start_time))

方式二:.to()

对 网络模型、数据(输入、标注)、损失函数调用.to()方法,方法中传入torch.device()对象。这种方式的好处在于不但可以使用GPU,还可以在有多块GPU时指定使用某块GPU

如下:

# cpu
CPU_device = torch.device("cpu")
# gpu 只有一块显卡无需指明使用第几块
GPU_device = torch.device("cuda")
# 第0块 gpu
GPU_0_device = torch.device("cuda:0")

完整代码如下:

import time
from torch.utils import tensorboard
from torch.utils.data import DataLoader
from _07_cifar10_model.cifar10_model import MyModel
import torchvision
import torch.nn

if __name__ == "__main__":

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

    start_time = time.time()
    # 准备训练数据集和测试数据集
    transform = torchvision.transforms.Compose({
        torchvision.transforms.ToTensor()
    })
    train_data = torchvision.datasets.CIFAR10("./dataset", train=True,
                                              transform=transform,
                                              download=True)
    test_data = torchvision.datasets.CIFAR10("./dataset", train=False,
                                             transform=transform,
                                             download=True)
    train_data_len = len(train_data)
    test_data_len = len(test_data)
    print("训练集的长度: {}".format(train_data_len))
    print("测试集的长度: {}".format(test_data_len))

    # 创建训练集和测试集的dataloader
    train_dataloader = DataLoader(dataset=train_data, batch_size=64,
                                  shuffle=True,
                                  num_workers=16)
    test_dataloader = DataLoader(dataset=test_data, batch_size=64,
                                 shuffle=True,
                                 num_workers=16)

    # 创建网络
    cifar10_model = MyModel()
    cifar10_model = cifar10_model.to(device)
    # if torch.cuda.is_available():
    #     cifar10_model = cifar10_model.cuda()

    # 创建损失函数
    loss_func = torch.nn.CrossEntropyLoss()
    loss_func = loss_func.to(device)
    # if torch.cuda.is_available():
    #     loss_func = loss_func.cuda()

    # 创建优化器
    # 学习率,科学计数的形式方便改动
    learning_rate = 1e-2
    optimizer = torch.optim.SGD(cifar10_model.parameters(), lr=learning_rate)

    # 训练次数
    total_train_step = 0
    # 训练轮次
    epoch = 20

    # 创建 tensorboard SummaryWriter
    writer = tensorboard.SummaryWriter("logs")

    for i in range(epoch):
        print("----------第 {} 轮训练开始-----------".format(i))

        # 模型进入训练模式,该方法在当前模型可有可无(加上是个好习惯)
        cifar10_model.train()
        for data in train_dataloader:
            images, targets = data

            images = images.to(device)
            targets = targets.to(device)
            # if torch.cuda.is_available():
            #     images = images.cuda()
            #     targets = targets.cuda()

            outputs = cifar10_model(images)
            loss = loss_func(outputs, targets)

            # 清空上一轮计算的梯度
            optimizer.zero_grad()
            # 反向传播计算梯度
            loss.backward()
            # 优化器优化参数(执行梯度下降)
            optimizer.step()

            total_train_step += 1
            writer.add_scalar("train/Loss", loss.item(), total_train_step)
            if total_train_step % 100 == 0:
                print("训练次数: {}, Loss: {}".
                      format(total_train_step, loss.item()))

        total_test_loss = 0.0
        total_accuracy = 0.0
        # 每轮 epoch 后计算模型在测试集上的loss表现
        # 测试时无需计算梯度,可加快计算速度
        # 模型进入验证(测试)模式,该方法在当前模型可有可无(加上是个好习惯)
        cifar10_model.eval()
        with torch.no_grad():
            for data in test_dataloader:
                images, targets = data

                images = images.to(device)
                targets = targets.to(device)
                # if torch.cuda.is_available():
                #     images = images.cuda()
                #     targets = targets.cuda()

                outputs = cifar10_model(images)
                loss = loss_func(outputs, targets)

                total_test_loss += loss.item()

                accuracy = (outputs.argmax(1) == targets).sum()
                total_accuracy += accuracy
            print("测试准确率:{}".format(total_accuracy/test_data_len))
            writer.add_scalar("test/Loss", total_test_loss, i)
            writer.add_scalar("test/accuracy", total_accuracy/test_data_len, i)

        # 保存每轮训练后的模型
        torch.save(cifar10_model.state_dict(),
                   "cifar10_model_state_dict_{}_epoch.pth".format(i))

    writer.close()

    end_time = time.time()
    print("耗时:{}".format(end_time - start_time))

模型验证

前面的小节中,我们已经将模型训练好了,且保存了每轮训练后的模型参数。现在我们选择一个在测试集上表现最好的模型进行恢复,然后在网上随便找些图片,看我们的模型能否分类正确。根据tensorboard的显示,表现最好的模型是在第18轮训练后的模型,能达到65%左右的正确率。预测图片如下:

Pytorch入门下 —— 其他

Pytorch入门下 —— 其他

根据CIFAR10数据集中定义,dogtarget5airplanetarget0

Pytorch入门下 —— 其他

预测代码如下:

import torch
from PIL import Image
import torchvision
from _07_cifar10_model.cifar10_model import MyModel

dog_img_path = "dog.png"
airplane_img_path = "airplane.png"
dog_img_PIL = Image.oPEn(dog_img_path)
airplane_img_PIL = Image.open(airplane_img_path)
# 将4通道RGBA转成3通道RGB
dog_img_PIL = dog_img_PIL.convert("RGB")
airplane_img_PIL = airplane_img_PIL.convert("RGB")

transform = torchvision.transforms.Compose([
    torchvision.transforms.Resize((32, 32)),
    torchvision.transforms.ToTensor()
])
dog_img_tensor = transform(dog_img_PIL)
airplane_img_tensor = transform(airplane_img_PIL)
# print(dog_img_tensor.Shape)
dog_img_tensor = torch.reshape(dog_img_tensor, (-1, 3, 32, 32))
airplane_img_tensor = torch.reshape(airplane_img_tensor, (1, 3, 32, 32))

cifar10_model = MyModel()
cifar10_model.load_state_dict(torch.load(
    "../_10_train_model/cifar10_model_state_dict_18_epoch.pth"))

cifar10_model.eval()
with torch.no_grad():
    output = cifar10_model(dog_img_tensor)
    print(output.argmax(1))
    output = cifar10_model(airplane_img_tensor)
    print(output.argmax(1))

输出如下:

tensor([7]) # 预测错误
tensor([0]) # 预测正确

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