pytorch实现 GoogLeNet——CNN经典网络模型详解( 三 )

pytorch实现 GoogLeNet——CNN经典网络模型详解

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三、GoogLeNet相关论文及下载地址[v1] Going Deeper withConvolutions, 6.67% test error,2014.9
论文地址:http://arxiv.org/abs/1409.4842
[v2] Batch Normalization:Accelerating Deep Network Training by Reducing Internal Covariate Shift, 4.8% test error,2015.2
论文地址:http://arxiv.org/abs/1502.03167
[v3] Rethinking theInception Architecture for Computer Vision, 3.5%test error,2015.12
论文地址:http://arxiv.org/abs/1512.00567
[v4] Inception-v4,Inception-ResNet and the Impact of Residual Connections on Learning, 3.08% test error,2016.2
代码:注:本次训练集下载在AlexNet博客有详细解说:https://blog.csdn.net/weixin_44023658/article/details/105798326
#model.pyimport torch.nn as nnimport torchimport torch.nn.functional as Fclass GoogLeNet(nn.Module):    def __init__(self, num_classes=1000, aux_logits=True, init_weights=False):        super(GoogLeNet, self).__init__()        self.aux_logits = aux_logits        self.conv1 = BasicConv2d(3, 64, kernel_size=7, stride=2, padding=3)        self.maxpool1 = nn.MaxPool2d(3, stride=2, ceil_mode=True)        self.conv2 = BasicConv2d(64, 64, kernel_size=1)        self.conv3 = BasicConv2d(64, 192, kernel_size=3, padding=1)        self.maxpool2 = nn.MaxPool2d(3, stride=2, ceil_mode=True)        self.inception3a = Inception(192, 64, 96, 128, 16, 32, 32)        self.inception3b = Inception(256, 128, 128, 192, 32, 96, 64)        self.maxpool3 = nn.MaxPool2d(3, stride=2, ceil_mode=True)        self.inception4a = Inception(480, 192, 96, 208, 16, 48, 64)        self.inception4b = Inception(512, 160, 112, 224, 24, 64, 64)        self.inception4c = Inception(512, 128, 128, 256, 24, 64, 64)        self.inception4d = Inception(512, 112, 144, 288, 32, 64, 64)        self.inception4e = Inception(528, 256, 160, 320, 32, 128, 128)        self.maxpool4 = nn.MaxPool2d(3, stride=2, ceil_mode=True)        self.inception5a = Inception(832, 256, 160, 320, 32, 128, 128)        self.inception5b = Inception(832, 384, 192, 384, 48, 128, 128)        if self.aux_logits:            self.aux1 = InceptionAux(512, num_classes)            self.aux2 = InceptionAux(528, num_classes)        self.avgpool = nn.AdaptiveAvgPool2d((1, 1))        self.dropout = nn.Dropout(0.4)        self.fc = nn.Linear(1024, num_classes)        if init_weights:            self._initialize_weights()    def forward(self, x):        # N x 3 x 224 x 224        x = self.conv1(x)        # N x 64 x 112 x 112        x = self.maxpool1(x)        # N x 64 x 56 x 56        x = self.conv2(x)        # N x 64 x 56 x 56        x = self.conv3(x)        # N x 192 x 56 x 56        x = self.maxpool2(x)        # N x 192 x 28 x 28        x = self.inception3a(x)        # N x 256 x 28 x 28        x = self.inception3b(x)        # N x 480 x 28 x 28        x = self.maxpool3(x)        # N x 480 x 14 x 14        x = self.inception4a(x)        # N x 512 x 14 x 14        if self.training and self.aux_logits:    # eval model lose this layer            aux1 = self.aux1(x)        x = self.inception4b(x)        # N x 512 x 14 x 14        x = self.inception4c(x)        # N x 512 x 14 x 14        x = self.inception4d(x)        # N x 528 x 14 x 14        if self.training and self.aux_logits:    # eval model lose this layer            aux2 = self.aux2(x)        x = self.inception4e(x)        # N x 832 x 14 x 14        x = self.maxpool4(x)        # N x 832 x 7 x 7        x = self.inception5a(x)        # N x 832 x 7 x 7        x = self.inception5b(x)        # N x 1024 x 7 x 7        x = self.avgpool(x)        # N x 1024 x 1 x 1        x = torch.flatten(x, 1)        # N x 1024        x = self.dropout(x)        x = self.fc(x)        # N x 1000 (num_classes)        if self.training and self.aux_logits:   # eval model lose this layer            return x, aux2, aux1        return x    def _initialize_weights(self):        for m in self.modules():            if isinstance(m, nn.Conv2d):                nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')                if m.bias is not None:                    nn.init.constant_(m.bias, 0)            elif isinstance(m, nn.Linear):                nn.init.normal_(m.weight, 0, 0.01)                nn.init.constant_(m.bias, 0)#inception结构class Inception(nn.Module):    def __init__(self, in_channels, ch1x1, ch3x3red, ch3x3, ch5x5red, ch5x5, pool_proj):        super(Inception, self).__init__()        self.branch1 = BasicConv2d(in_channels, ch1x1, kernel_size=1)        self.branch2 = nn.Sequential(            BasicConv2d(in_channels, ch3x3red, kernel_size=1),            BasicConv2d(ch3x3red, ch3x3, kernel_size=3, padding=1)   # 保证输出大小等于输入大小        )        self.branch3 = nn.Sequential(            BasicConv2d(in_channels, ch5x5red, kernel_size=1),            BasicConv2d(ch5x5red, ch5x5, kernel_size=5, padding=2)   # 保证输出大小等于输入大小        )        self.branch4 = nn.Sequential(            nn.MaxPool2d(kernel_size=3, stride=1, padding=1),            BasicConv2d(in_channels, pool_proj, kernel_size=1)        )    def forward(self, x):        branch1 = self.branch1(x)        branch2 = self.branch2(x)        branch3 = self.branch3(x)        branch4 = self.branch4(x)        outputs = [branch1, branch2, branch3, branch4]        return torch.cat(outputs, 1)#辅助分类器class InceptionAux(nn.Module):    def __init__(self, in_channels, num_classes):        super(InceptionAux, self).__init__()        self.averagePool = nn.AvgPool2d(kernel_size=5, stride=3)        self.conv = BasicConv2d(in_channels, 128, kernel_size=1)  # output[batch, 128, 4, 4]        self.fc1 = nn.Linear(2048, 1024)        self.fc2 = nn.Linear(1024, num_classes)    def forward(self, x):        # aux1: N x 512 x 14 x 14, aux2: N x 528 x 14 x 14        x = self.averagePool(x)        # aux1: N x 512 x 4 x 4, aux2: N x 528 x 4 x 4        x = self.conv(x)        # N x 128 x 4 x 4        x = torch.flatten(x, 1)        x = F.dropout(x, 0.5, training=self.training)        # N x 2048        x = F.relu(self.fc1(x), inplace=True)        x = F.dropout(x, 0.5, training=self.training)        # N x 1024        x = self.fc2(x)        # N x num_classes        return xclass BasicConv2d(nn.Module):    def __init__(self, in_channels, out_channels, **kwargs):        super(BasicConv2d, self).__init__()        self.conv = nn.Conv2d(in_channels, out_channels, **kwargs)        self.relu = nn.ReLU(inplace=True)    def forward(self, x):        x = self.conv(x)        x = self.relu(x)        return x


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