Alexnet网络详解代码:手撕Alexnet卷积神经网络-pytorch-详细注释版(可以直接替换自己数据集)-直接放置自己的数据集就能直接跑。跑的代码有问题的可以在评论区指出,看到了会回复。训练代码和预测代码均有。_小馨馨的小翟的博客-CSDN博客_alexnet神经网络代码

VGG网络详解代码:手撕VGG卷积神经网络-pytorch-详细注释版(可以直接替换自己数据集)-直接放置自己的数据集就能直接跑。跑的代码有问题的可以在评论区指出,看到了会回复。训练代码和预测代码均有。_小馨馨的小翟的博客-CSDN博客

Resnet网络详解代码:手撕Resnet卷积神经网络-pytorch-详细注释版(可以直接替换自己数据集)-直接放置自己的数据集就能直接跑。跑的代码有问题的可以在评论区指出,看到了会回复。训练代码和预测代码均有。_小馨馨的小翟的博客-CSDN博客

Googlenet网络详解代码:手撕Googlenet卷积神经网络-pytorch-详细注释版(可以直接替换自己数据集)-直接放置自己的数据集就能直接跑。跑的代码有问题的可以在评论区指出,看到了会回复。训练代码和预测代码均有。_小馨馨的小翟的博客-CSDN博客_cnn测试集准确率低

集成学习模型融合网络详解代码:

集成学习-模型融合(Lenet,Alexnet,Vgg)三个模型进行融合-附源代码-宇宙的尽头一定是融合模型而不是单个模型。_小馨馨的小翟的博客-CSDN博客_torch模型融合

深度学习常用数据增强,数据扩充代码数据缩放代码:

深度学习数据增强方法-内含(亮度增强,对比度增强,旋转图图像,翻转图像,仿射变化扩充图像,错切变化扩充图像,HSV数据增强)七种方式进行增强-每种扩充一张实现7倍扩)+ 图像缩放代码-批量_小馨馨的小翟的博客-CSDN博客_训练数据增强

Resnet(Deep residual network, ResNet),深度残差神经网络,卷积神经网络历史在具有划时代意义的神经网络。与Alexnet和VGG不同的是,网络结构上就有很大的改变,在大家为了提升卷积神经网络的性能在不断提升网络深度的时候,大家发现随着网络深度的提升,网络的效果变得越来越差,甚至出现了网络的退化问题,80层的网络比30层的效果还差,深度网络存在的梯度消失和爆炸问题越来越严重,这使得训练一个优异的深度学习模型变得更加艰难,在这种情况下,网络结构图

事实上在一些目标检测算法例如yolo系列的算法当中也用到了Resnet的结构,而且在很多多尺度特征融合的算法里 也是采用类似的方法,多层不同的输出组合在一起,因此学好Resnet网络对于以后学习目标检测算法具有深刻的意义。

导入库:

import torchimport torchvisionimport torchvision.modelsimport osfrom matplotlib import pyplot as pltfrom tqdm import tqdmfrom torch import nnfrom torch.utils.data import DataLoaderfrom torchvision.transforms import transforms

图像预处理:

将图像放缩成120*120进行处理,如果需要放缩成其他比例的,直接修改代码中的120成其他数即可。

data_transform = {    "train": transforms.Compose([transforms.RandomResizedCrop(120),                                 transforms.RandomHorizontalFlip(),                                 transforms.ToTensor(),                                 transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))]),    "val": transforms.Compose([transforms.Resize((120, 120)),  # cannot 224, must (224, 224)                               transforms.ToTensor(),                               transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))])}

导入数据:

将数据像挤牙膏似的一点一点的抽出去,设置相应的batc_size

自己的数据放在跟代码相同的文件夹下新建一个data文件夹,data文件夹里的新建一个train文件夹用于放置训练集的图片。同理新建一个val文件夹用于放置测试集的图片。

train_data = torchvision.datasets.ImageFolder(root = "./data/train" ,   transform = data_transform["train"])traindata = DataLoader(dataset=train_data, batch_size=128, shuffle=True, num_workers=0)  # 将训练数据以每次32张图片的形式抽出进行训练test_data = torchvision.datasets.ImageFolder(root = "./data/val" , transform = data_transform["val"])train_size = len(train_data)  # 训练集的长度test_size = len(test_data)  # 测试集的长度print(train_size)   #输出训练集长度看一下,相当于看看有几张图片print(test_size)    #输出测试集长度看一下,相当于看看有几张图片testdata = DataLoader(dataset=test_data, batch_size=128, shuffle=True, num_workers=0)  # 将训练数据以每次32张图片的形式抽出进行测试

设置GPU 和 CPU的使用:

有GPU则调用GPU,没有的话就调用CPU

device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")print("using {} device.".format(device))

构建Resnet网络:

因为Resnet网络太深,所以一般采用迁移学习的方法进行搭建

class BasicBlock(nn.Module):    expansion = 1    def __init__(self, in_channel, out_channel, stride=1, downsample=None, **kwargs):        super(BasicBlock, self).__init__()        self.conv1 = nn.Conv2d(in_channels=in_channel, out_channels=out_channel,                               kernel_size=3, stride=stride, padding=1, bias=False)        self.bn1 = nn.BatchNorm2d(out_channel)        self.relu = nn.ReLU()        self.conv2 = nn.Conv2d(in_channels=out_channel, out_channels=out_channel,                               kernel_size=3, stride=1, padding=1, bias=False)        self.bn2 = nn.BatchNorm2d(out_channel)        self.downsample = downsample    def forward(self, x):        identity = x        if self.downsample is not None:            identity = self.downsample(x)        out = self.conv1(x)        out = self.bn1(out)        out = self.relu(out)        out = self.conv2(out)        out = self.bn2(out)        out += identity        out = self.relu(out)        return outclass Bottleneck(nn.Module):    expansion = 4    def __init__(self, in_channel, out_channel, stride=1, downsample=None,                 groups=1, width_per_group=64):        super(Bottleneck, self).__init__()        width = int(out_channel * (width_per_group / 64.)) * groups        self.conv1 = nn.Conv2d(in_channels=in_channel, out_channels=width,                               kernel_size=1, stride=1, bias=False)  # squeeze channels        self.bn1 = nn.BatchNorm2d(width)        # -----------------------------------------        self.conv2 = nn.Conv2d(in_channels=width, out_channels=width, groups=groups,                               kernel_size=3, stride=stride, bias=False, padding=1)        self.bn2 = nn.BatchNorm2d(width)        # -----------------------------------------        self.conv3 = nn.Conv2d(in_channels=width, out_channels=out_channel*self.expansion,                               kernel_size=1, stride=1, bias=False)  # unsqueeze channels        self.bn3 = nn.BatchNorm2d(out_channel*self.expansion)        self.relu = nn.ReLU(inplace=True)        self.downsample = downsample    def forward(self, x):        identity = x        if self.downsample is not None:            identity = self.downsample(x)        out = self.conv1(x)        out = self.bn1(out)        out = self.relu(out)        out = self.conv2(out)        out = self.bn2(out)        out = self.relu(out)        out = self.conv3(out)        out = self.bn3(out)        out += identity        out = self.relu(out)        return outclass ResNet(nn.Module):    def __init__(self,                 block,                 blocks_num,                 num_classes=7,#种类修改的地方,你是几种,就把这个改成几,我是7中所以这里是7                 include_top=True,                 groups=1,                 width_per_group=64):        super(ResNet, self).__init__()        self.include_top = include_top        self.in_channel = 64        self.groups = groups        self.width_per_group = width_per_group        self.conv1 = nn.Conv2d(3, self.in_channel, kernel_size=7, stride=2,                               padding=3, bias=False)        self.bn1 = nn.BatchNorm2d(self.in_channel)        self.relu = nn.ReLU(inplace=True)        self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)        self.layer1 = self._make_layer(block, 64, blocks_num[0])        self.layer2 = self._make_layer(block, 128, blocks_num[1], stride=2)        self.layer3 = self._make_layer(block, 256, blocks_num[2], stride=2)        self.layer4 = self._make_layer(block, 512, blocks_num[3], stride=2)        if self.include_top:            self.avgpool = nn.AdaptiveAvgPool2d((1, 1))  # output size = (1, 1)            self.fc = nn.Linear(512 * block.expansion, num_classes)        for m in self.modules():            if isinstance(m, nn.Conv2d):                nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')    def _make_layer(self, block, channel, block_num, stride=1):        downsample = None        if stride != 1 or self.in_channel != channel * block.expansion:            downsample = nn.Sequential(                nn.Conv2d(self.in_channel, channel * block.expansion, kernel_size=1, stride=stride, bias=False),                nn.BatchNorm2d(channel * block.expansion))        layers = []        layers.append(block(self.in_channel,                            channel,                            downsample=downsample,                            stride=stride,                            groups=self.groups,                            width_per_group=self.width_per_group))        self.in_channel = channel * block.expansion        for _ in range(1, block_num):            layers.append(block(self.in_channel,                                channel,                                groups=self.groups,                                width_per_group=self.width_per_group))        return nn.Sequential(*layers)    def forward(self, x):        x = self.conv1(x)        x = self.bn1(x)        x = self.relu(x)        x = self.maxpool(x)        x = self.layer1(x)        x = self.layer2(x)        x = self.layer3(x)        x = self.layer4(x)        if self.include_top:            x = self.avgpool(x)            x = torch.flatten(x, 1)            x = self.fc(x)        return xdef resnet34(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet34-333f7ec4.pth    return ResNet(BasicBlock, [3, 4, 6, 3], num_classes=num_classes, include_top=include_top)def resnet50(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet50-19c8e357.pth    return ResNet(Bottleneck, [3, 4, 6, 3], num_classes=num_classes, include_top=include_top)def resnet101(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet101-5d3b4d8f.pth    return ResNet(Bottleneck, [3, 4, 23, 3], num_classes=num_classes, include_top=include_top)def resnext50_32x4d(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnext50_32x4d-7cdf4587.pth    groups = 32    width_per_group = 4    return ResNet(Bottleneck, [3, 4, 6, 3],                  num_classes=num_classes,                  include_top=include_top,                  groups=groups,                  width_per_group=width_per_group)def resnext101_32x8d(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnext101_32x8d-8ba56ff5.pth    groups = 32    width_per_group = 8    return ResNet(Bottleneck, [3, 4, 23, 3],                  num_classes=num_classes,                  include_top=include_top,                  groups=groups,                  width_per_group=width_per_group)net = resnet34()# load pretrain weights# download url: https://download.pytorch.org/models/resnet34-333f7ec4.pthmodel_weight_path = "./resnet34-pre.pth"  #加载resnet的预训练模型assert os.path.exists(model_weight_path), "file {} does not exist.".format(model_weight_path)net.load_state_dict(torch.load(model_weight_path, map_location=device))net.to(device)print(net.to(device))  #输出模型结构

启动模型,测试模型输出:

test1 = torch.ones(64, 3, 120, 120)  # 测试一下输出的形状大小 输入一个64,3,120,120的向量test1 = net(test1.to(device))    #将向量打入神经网络进行测试print(test1.shape)  #查看输出的结果

设置训练需要的参数,epoch,学习率learning 优化器。损失函数。

epoch = 10  # 迭代次数即训练次数learning = 0.001  # 学习率optimizer = torch.optim.Adam(net.parameters(), lr=learning)  # 使用Adam优化器-写论文的话可以具体查一下这个优化器的原理loss = nn.CrossEntropyLoss()  # 损失计算方式,交叉熵损失函数

设置四个空数组,用来存放训练集的loss和accuracy 测试集的loss和 accuracy

train_loss_all = []train_accur_all = []test_loss_all = []test_accur_all = []

开始训练:

for i in range(epoch):  #开始迭代    train_loss = 0   #训练集的损失初始设为0    train_num = 0.0   #    train_accuracy = 0.0  #训练集的准确率初始设为0    net.train()   #将模型设置成 训练模式    train_bar = tqdm(traindata)  #用于进度条显示,没啥实际用处    for step, data in enumerate(train_bar):  #开始迭代跑, enumerate这个函数不懂可以查查,将训练集分为 data是序号,data是数据        img, target = data    #将data 分位 img图片,target标签        optimizer.zero_grad()  # 清空历史梯度        outputs = net(img.to(device))  # 将图片打入网络进行训练,outputs是输出的结果        loss1 = loss(outputs, target.to(device))  # 计算神经网络输出的结果outputs与图片真实标签target的差别-这就是我们通常情况下称为的损失        outputs = torch.argmax(outputs, 1)   #会输出10个值,最大的值就是我们预测的结果 求最大值        loss1.backward()   #神经网络反向传播        optimizer.step()  #梯度优化 用上面的abam优化        train_loss += abs(loss1.item()) * img.size(0)  #将所有损失的绝对值加起来        accuracy = torch.sum(outputs == target.to(device))   #outputs == target的 即使预测正确的,统计预测正确的个数,从而计算准确率        train_accuracy = train_accuracy + accuracy   #求训练集的准确率        train_num += img.size(0)  #    print("epoch:{} , train-Loss:{} , train-accuracy:{}".format(i + 1, train_loss / train_num,   #输出训练情况                                                                train_accuracy / train_num))    train_loss_all.append(train_loss / train_num)   #将训练的损失放到一个列表里 方便后续画图    train_accur_all.append(train_accuracy.double().item() / train_num)#训练集的准确率

开始测试:

    test_loss = 0   #同上 测试损失    test_accuracy = 0.0  #测试准确率    test_num = 0    net.eval()   #将模型调整为测试模型    with torch.no_grad():  #清空历史梯度,进行测试  与训练最大的区别是测试过程中取消了反向传播        test_bar = tqdm(testdata)        for data in test_bar:            img, target = data            outputs = net(img.to(device))            loss2 = loss(outputs, target.to(device))            outputs = torch.argmax(outputs, 1)            test_loss = test_loss + abs(loss2.item()) * img.size(0)            accuracy = torch.sum(outputs == target.to(device))            test_accuracy = test_accuracy + accuracy            test_num += img.size(0)    print("test-Loss:{} , test-accuracy:{}".format(test_loss / test_num, test_accuracy / test_num))    test_loss_all.append(test_loss / test_num)    test_accur_all.append(test_accuracy.double().item() / test_num)

绘制训练集loss和accuracy图 和测试集的loss和accuracy图:

#下面的是画图过程,将上述存放的列表  画出来即可plt.figure(figsize=(12, 4))plt.subplot(1, 2, 1)plt.plot(range(epoch), train_loss_all,         "ro-", label="Train loss")plt.plot(range(epoch), test_loss_all,         "bs-", label="test loss")plt.legend()plt.xlabel("epoch")plt.ylabel("Loss")plt.subplot(1, 2, 2)plt.plot(range(epoch), train_accur_all,         "ro-", label="Train accur")plt.plot(range(epoch), test_accur_all,         "bs-", label="test accur")plt.xlabel("epoch")plt.ylabel("acc")plt.legend()plt.show()torch.save(net.state_dict(), "Resnet.pth")print("模型已保存")

全部train训练代码:

import torchimport torchvisionimport torchvision.modelsimport osfrom matplotlib import pyplot as pltfrom tqdm import tqdmfrom torch import nnfrom torch.utils.data import DataLoaderfrom torchvision.transforms import transformsfrom sklearn.metrics import accuracy_score, confusion_matrix, classification_reportdata_transform = {    "train": transforms.Compose([transforms.RandomResizedCrop(120),                                 transforms.RandomHorizontalFlip(),                                 transforms.ToTensor(),                                 transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))]),    "val": transforms.Compose([transforms.Resize((120, 120)),  # cannot 224, must (224, 224)                               transforms.ToTensor(),                               transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))])}train_data = torchvision.datasets.ImageFolder(root = "./data/train" ,   transform = data_transform["train"])traindata = DataLoader(dataset=train_data, batch_size=128, shuffle=True, num_workers=0)  # 将训练数据以每次32张图片的形式抽出进行训练test_data = torchvision.datasets.ImageFolder(root = "./data/val" , transform = data_transform["val"])train_size = len(train_data)  # 训练集的长度test_size = len(test_data)  # 测试集的长度print(train_size)   #输出训练集长度看一下,相当于看看有几张图片print(test_size)    #输出测试集长度看一下,相当于看看有几张图片testdata = DataLoader(dataset=test_data, batch_size=128, shuffle=True, num_workers=0)  # 将训练数据以每次32张图片的形式抽出进行测试device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")print("using {} device.".format(device))class BasicBlock(nn.Module):    expansion = 1    def __init__(self, in_channel, out_channel, stride=1, downsample=None, **kwargs):        super(BasicBlock, self).__init__()        self.conv1 = nn.Conv2d(in_channels=in_channel, out_channels=out_channel,                               kernel_size=3, stride=stride, padding=1, bias=False)        self.bn1 = nn.BatchNorm2d(out_channel)        self.relu = nn.ReLU()        self.conv2 = nn.Conv2d(in_channels=out_channel, out_channels=out_channel,                               kernel_size=3, stride=1, padding=1, bias=False)        self.bn2 = nn.BatchNorm2d(out_channel)        self.downsample = downsample    def forward(self, x):        identity = x        if self.downsample is not None:            identity = self.downsample(x)        out = self.conv1(x)        out = self.bn1(out)        out = self.relu(out)        out = self.conv2(out)        out = self.bn2(out)        out += identity        out = self.relu(out)        return outclass Bottleneck(nn.Module):      expansion = 4    def __init__(self, in_channel, out_channel, stride=1, downsample=None,                 groups=1, width_per_group=64):        super(Bottleneck, self).__init__()        width = int(out_channel * (width_per_group / 64.)) * groups        self.conv1 = nn.Conv2d(in_channels=in_channel, out_channels=width,                               kernel_size=1, stride=1, bias=False)  # squeeze channels        self.bn1 = nn.BatchNorm2d(width)        # -----------------------------------------        self.conv2 = nn.Conv2d(in_channels=width, out_channels=width, groups=groups,                               kernel_size=3, stride=stride, bias=False, padding=1)        self.bn2 = nn.BatchNorm2d(width)        # -----------------------------------------        self.conv3 = nn.Conv2d(in_channels=width, out_channels=out_channel*self.expansion,                               kernel_size=1, stride=1, bias=False)  # unsqueeze channels        self.bn3 = nn.BatchNorm2d(out_channel*self.expansion)        self.relu = nn.ReLU(inplace=True)        self.downsample = downsample    def forward(self, x):        identity = x        if self.downsample is not None:            identity = self.downsample(x)        out = self.conv1(x)        out = self.bn1(out)        out = self.relu(out)        out = self.conv2(out)        out = self.bn2(out)        out = self.relu(out)        out = self.conv3(out)        out = self.bn3(out)        out += identity        out = self.relu(out)        return outclass ResNet(nn.Module):    def __init__(self,                 block,                 blocks_num,                 num_classes=7,                 include_top=True,                 groups=1,                 width_per_group=64):        super(ResNet, self).__init__()        self.include_top = include_top        self.in_channel = 64        self.groups = groups        self.width_per_group = width_per_group        self.conv1 = nn.Conv2d(3, self.in_channel, kernel_size=7, stride=2,                               padding=3, bias=False)        self.bn1 = nn.BatchNorm2d(self.in_channel)        self.relu = nn.ReLU(inplace=True)        self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)        self.layer1 = self._make_layer(block, 64, blocks_num[0])        self.layer2 = self._make_layer(block, 128, blocks_num[1], stride=2)        self.layer3 = self._make_layer(block, 256, blocks_num[2], stride=2)        self.layer4 = self._make_layer(block, 512, blocks_num[3], stride=2)        if self.include_top:            self.avgpool = nn.AdaptiveAvgPool2d((1, 1))  # output size = (1, 1)            self.fc = nn.Linear(512 * block.expansion, num_classes)        for m in self.modules():            if isinstance(m, nn.Conv2d):                nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')    def _make_layer(self, block, channel, block_num, stride=1):        downsample = None        if stride != 1 or self.in_channel != channel * block.expansion:            downsample = nn.Sequential(                nn.Conv2d(self.in_channel, channel * block.expansion, kernel_size=1, stride=stride, bias=False),                nn.BatchNorm2d(channel * block.expansion))        layers = []        layers.append(block(self.in_channel,                            channel,                            downsample=downsample,                            stride=stride,                            groups=self.groups,                            width_per_group=self.width_per_group))        self.in_channel = channel * block.expansion        for _ in range(1, block_num):            layers.append(block(self.in_channel,                                channel,                                groups=self.groups,                                width_per_group=self.width_per_group))        return nn.Sequential(*layers)    def forward(self, x):        x = self.conv1(x)        x = self.bn1(x)        x = self.relu(x)        x = self.maxpool(x)        x = self.layer1(x)        x = self.layer2(x)        x = self.layer3(x)        x = self.layer4(x)        if self.include_top:            x = self.avgpool(x)            x = torch.flatten(x, 1)            x = self.fc(x)        return xdef resnet34(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet34-333f7ec4.pth    return ResNet(BasicBlock, [3, 4, 6, 3], num_classes=num_classes, include_top=include_top)def resnet50(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet50-19c8e357.pth    return ResNet(Bottleneck, [3, 4, 6, 3], num_classes=num_classes, include_top=include_top)def resnet101(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet101-5d3b4d8f.pth    return ResNet(Bottleneck, [3, 4, 23, 3], num_classes=num_classes, include_top=include_top)def resnext50_32x4d(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnext50_32x4d-7cdf4587.pth    groups = 32    width_per_group = 4    return ResNet(Bottleneck, [3, 4, 6, 3],                  num_classes=num_classes,                  include_top=include_top,                  groups=groups,                  width_per_group=width_per_group)def resnext101_32x8d(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnext101_32x8d-8ba56ff5.pth    groups = 32    width_per_group = 8    return ResNet(Bottleneck, [3, 4, 23, 3],                  num_classes=num_classes,                  include_top=include_top,                  groups=groups,                  width_per_group=width_per_group)net = resnet34()# load pretrain weights# download url: https://download.pytorch.org/models/resnet34-333f7ec4.pthmodel_weight_path = "./resnet34-pre.pth"assert os.path.exists(model_weight_path), "file {} does not exist.".format(model_weight_path)net.load_state_dict(torch.load(model_weight_path, map_location=device))net.to(device)print(net.to(device))  #输出模型结构test1 = torch.ones(64, 3, 120, 120)  # 测试一下输出的形状大小 输入一个64,3,120,120的向量test1 = net(test1.to(device))    #将向量打入神经网络进行测试print(test1.shape)  #查看输出的结果epoch = 10  # 迭代次数即训练次数learning = 0.001  # 学习率optimizer = torch.optim.Adam(net.parameters(), lr=learning)  # 使用Adam优化器-写论文的话可以具体查一下这个优化器的原理loss = nn.CrossEntropyLoss()  # 损失计算方式,交叉熵损失函数train_loss_all = []  # 存放训练集损失的数组train_accur_all = []  # 存放训练集准确率的数组test_loss_all = []  # 存放测试集损失的数组test_accur_all = []  # 存放测试集准确率的数组for i in range(epoch):  #开始迭代    train_loss = 0   #训练集的损失初始设为0    train_num = 0.0   #    train_accuracy = 0.0  #训练集的准确率初始设为0    net.train()   #将模型设置成 训练模式    train_bar = tqdm(traindata)  #用于进度条显示,没啥实际用处    for step, data in enumerate(train_bar):  #开始迭代跑, enumerate这个函数不懂可以查查,将训练集分为 data是序号,data是数据        img, target = data    #将data 分位 img图片,target标签        optimizer.zero_grad()  # 清空历史梯度        outputs = net(img.to(device))  # 将图片打入网络进行训练,outputs是输出的结果        loss1 = loss(outputs, target.to(device))  # 计算神经网络输出的结果outputs与图片真实标签target的差别-这就是我们通常情况下称为的损失        outputs = torch.argmax(outputs, 1)   #会输出10个值,最大的值就是我们预测的结果 求最大值        loss1.backward()   #神经网络反向传播        optimizer.step()  #梯度优化 用上面的abam优化        train_loss += abs(loss1.item()) * img.size(0)  #将所有损失的绝对值加起来        accuracy = torch.sum(outputs == target.to(device))   #outputs == target的 即使预测正确的,统计预测正确的个数,从而计算准确率        train_accuracy = train_accuracy + accuracy   #求训练集的准确率        train_num += img.size(0)  #    print("epoch:{} , train-Loss:{} , train-accuracy:{}".format(i + 1, train_loss / train_num,   #输出训练情况                                                                train_accuracy / train_num))    train_loss_all.append(train_loss / train_num)   #将训练的损失放到一个列表里 方便后续画图    train_accur_all.append(train_accuracy.double().item() / train_num)#训练集的准确率    test_loss = 0   #同上 测试损失    test_accuracy = 0.0  #测试准确率    test_num = 0    net.eval()   #将模型调整为测试模型    with torch.no_grad():  #清空历史梯度,进行测试  与训练最大的区别是测试过程中取消了反向传播        test_bar = tqdm(testdata)        for data in test_bar:            img, target = data            outputs = net(img.to(device))            loss2 = loss(outputs, target.to(device))            outputs = torch.argmax(outputs, 1)            test_loss = test_loss + abs(loss2.item()) * img.size(0)            accuracy = torch.sum(outputs == target.to(device))            test_accuracy = test_accuracy + accuracy            test_num += img.size(0)    print("test-Loss:{} , test-accuracy:{}".format(test_loss / test_num, test_accuracy / test_num))    test_loss_all.append(test_loss / test_num)    test_accur_all.append(test_accuracy.double().item() / test_num)#下面的是画图过程,将上述存放的列表  画出来即可plt.figure(figsize=(12, 4))plt.subplot(1, 2, 1)plt.plot(range(epoch), train_loss_all,         "ro-", label="Train loss")plt.plot(range(epoch), test_loss_all,         "bs-", label="test loss")plt.legend()plt.xlabel("epoch")plt.ylabel("Loss")plt.subplot(1, 2, 2)plt.plot(range(epoch), train_accur_all,         "ro-", label="Train accur")plt.plot(range(epoch), test_accur_all,         "bs-", label="test accur")plt.xlabel("epoch")plt.ylabel("acc")plt.legend()plt.show()torch.save(net.state_dict(), "Resnet.pth")print("模型已保存")

全部predict代码:

import torchfrom PIL import Imagefrom torch import nnfrom torchvision.transforms import transformsimage_path = "1.JPG"  # 相对路径 导入图片trans = transforms.Compose([transforms.Resize((120, 120)),                            transforms.ToTensor()])  # 将图片缩放为跟训练集图片的大小一样 方便预测,且将图片转换为张量image = Image.open(image_path)  # 打开图片print(image)  # 输出图片 看看图片格式image = image.convert("RGB")  # 将图片转换为RGB格式image = trans(image)  # 上述的缩放和转张量操作在这里实现print(image)  # 查看转换后的样子image = torch.unsqueeze(image, dim=0)  # 将图片维度扩展一维classes = ["1", "2", "3", "4", "5", "6", "7"]  # 预测种类#自己是几种,这里就改成自己种类的字符数组class BasicBlock(nn.Module):    expansion = 1    def __init__(self, in_channel, out_channel, stride=1, downsample=None, **kwargs):        super(BasicBlock, self).__init__()        self.conv1 = nn.Conv2d(in_channels=in_channel, out_channels=out_channel,                               kernel_size=3, stride=stride, padding=1, bias=False)        self.bn1 = nn.BatchNorm2d(out_channel)        self.relu = nn.ReLU()        self.conv2 = nn.Conv2d(in_channels=out_channel, out_channels=out_channel,                               kernel_size=3, stride=1, padding=1, bias=False)        self.bn2 = nn.BatchNorm2d(out_channel)        self.downsample = downsample    def forward(self, x):        identity = x        if self.downsample is not None:            identity = self.downsample(x)        out = self.conv1(x)        out = self.bn1(out)        out = self.relu(out)        out = self.conv2(out)        out = self.bn2(out)        out += identity        out = self.relu(out)        return outclass Bottleneck(nn.Module):    """    注意:原论文中,在虚线残差结构的主分支上,第一个1x1卷积层的步距是2,第二个3x3卷积层步距是1。    但在pytorch官方实现过程中是第一个1x1卷积层的步距是1,第二个3x3卷积层步距是2,    这么做的好处是能够在top1上提升大概0.5%的准确率。    可参考Resnet v1.5 https://ngc.nvidia.com/catalog/model-scripts/nvidia:resnet_50_v1_5_for_pytorch    """    expansion = 4    def __init__(self, in_channel, out_channel, stride=1, downsample=None,                 groups=1, width_per_group=64):        super(Bottleneck, self).__init__()        width = int(out_channel * (width_per_group / 64.)) * groups        self.conv1 = nn.Conv2d(in_channels=in_channel, out_channels=width,                               kernel_size=1, stride=1, bias=False)  # squeeze channels        self.bn1 = nn.BatchNorm2d(width)        # -----------------------------------------        self.conv2 = nn.Conv2d(in_channels=width, out_channels=width, groups=groups,                               kernel_size=3, stride=stride, bias=False, padding=1)        self.bn2 = nn.BatchNorm2d(width)        # -----------------------------------------        self.conv3 = nn.Conv2d(in_channels=width, out_channels=out_channel*self.expansion,                               kernel_size=1, stride=1, bias=False)  # unsqueeze channels        self.bn3 = nn.BatchNorm2d(out_channel*self.expansion)        self.relu = nn.ReLU(inplace=True)        self.downsample = downsample    def forward(self, x):        identity = x        if self.downsample is not None:            identity = self.downsample(x)        out = self.conv1(x)        out = self.bn1(out)        out = self.relu(out)        out = self.conv2(out)        out = self.bn2(out)        out = self.relu(out)        out = self.conv3(out)        out = self.bn3(out)        out += identity        out = self.relu(out)        return outclass ResNet(nn.Module):    def __init__(self,                 block,                 blocks_num,                 num_classes=7,                 include_top=True,                 groups=1,                 width_per_group=64):        super(ResNet, self).__init__()        self.include_top = include_top        self.in_channel = 64        self.groups = groups        self.width_per_group = width_per_group        self.conv1 = nn.Conv2d(3, self.in_channel, kernel_size=7, stride=2,                               padding=3, bias=False)        self.bn1 = nn.BatchNorm2d(self.in_channel)        self.relu = nn.ReLU(inplace=True)        self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)        self.layer1 = self._make_layer(block, 64, blocks_num[0])        self.layer2 = self._make_layer(block, 128, blocks_num[1], stride=2)        self.layer3 = self._make_layer(block, 256, blocks_num[2], stride=2)        self.layer4 = self._make_layer(block, 512, blocks_num[3], stride=2)        if self.include_top:            self.avgpool = nn.AdaptiveAvgPool2d((1, 1))  # output size = (1, 1)            self.fc = nn.Linear(512 * block.expansion, num_classes)        for m in self.modules():            if isinstance(m, nn.Conv2d):                nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')    def _make_layer(self, block, channel, block_num, stride=1):        downsample = None        if stride != 1 or self.in_channel != channel * block.expansion:            downsample = nn.Sequential(                nn.Conv2d(self.in_channel, channel * block.expansion, kernel_size=1, stride=stride, bias=False),                nn.BatchNorm2d(channel * block.expansion))        layers = []        layers.append(block(self.in_channel,                            channel,                            downsample=downsample,                            stride=stride,                            groups=self.groups,                            width_per_group=self.width_per_group))        self.in_channel = channel * block.expansion        for _ in range(1, block_num):            layers.append(block(self.in_channel,                                channel,                                groups=self.groups,                                width_per_group=self.width_per_group))        return nn.Sequential(*layers)    def forward(self, x):        x = self.conv1(x)        x = self.bn1(x)        x = self.relu(x)        x = self.maxpool(x)        x = self.layer1(x)        x = self.layer2(x)        x = self.layer3(x)        x = self.layer4(x)        if self.include_top:            x = self.avgpool(x)            x = torch.flatten(x, 1)            x = self.fc(x)        return xdef resnet34(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet34-333f7ec4.pth    return ResNet(BasicBlock, [3, 4, 6, 3], num_classes=num_classes, include_top=include_top)def resnet50(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet50-19c8e357.pth    return ResNet(Bottleneck, [3, 4, 6, 3], num_classes=num_classes, include_top=include_top)def resnet101(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnet101-5d3b4d8f.pth    return ResNet(Bottleneck, [3, 4, 23, 3], num_classes=num_classes, include_top=include_top)def resnext50_32x4d(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnext50_32x4d-7cdf4587.pth    groups = 32    width_per_group = 4    return ResNet(Bottleneck, [3, 4, 6, 3],                  num_classes=num_classes,                  include_top=include_top,                  groups=groups,                  width_per_group=width_per_group)def resnext101_32x8d(num_classes=1000, include_top=True):    # https://download.pytorch.org/models/resnext101_32x8d-8ba56ff5.pth    groups = 32    width_per_group = 8    return ResNet(Bottleneck, [3, 4, 23, 3],                  num_classes=num_classes,                  include_top=include_top,                  groups=groups,                  width_per_group=width_per_group)# 以上是神经网络结构,因为读取了模型之后代码还得知道神经网络的结构才能进行预测device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")  # 将代码放入GPU进行训练print("using {} device.".format(device))net = resnet34()net.load_state_dict(torch.load("Resnet.pth", map_location=device))net.to(device)net.eval()  # 关闭梯度,将模型调整为测试模式with torch.no_grad():  # 梯度清零    outputs = net(image.to(device))  # 将图片打入神经网络进行测试    print(net)  # 输出模型结构    print(outputs)  # 输出预测的张量数组    ans = (outputs.argmax(1)).item()  # 最大的值即为预测结果,找出最大值在数组中的序号,    # 对应找其在种类中的序号即可然后输出即为其种类    print(classes[ans])##输出的是那种即为预测结果

代码下载链接:链接:https://pan.baidu.com/s/1el2kss9x1qiSLd4B4H3Iyw
提取码:m3zq

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