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1.BasicConv2d类 2.Inception 3.InceptionAux(nn.Module):#辅助分类器 4.GoogLeNet
其中上表格查的第一个参数,输入:
import torch.nn as nn import torch import torch.nn.functional as F class GoogLeNet(nn.Module): def __init__(self, num_classes=1000, aux_logits=True, init_weights=False):#aux_logits=是否使用辅助分类器 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)#如果是小数,ceil_mode向上取整,false向下 self.conv2 = BasicConv2d(64, 64, kernel_size=1)#第二份64是查的 self.conv3 = BasicConv2d(64, 192, kernel_size=3, padding=1)#第二份192是查的 self.maxpool2 = nn.MaxPool2d(3, stride=2, ceil_mode=True) self.inception3a = Inception(192, 64, 96, 128, 16, 32, 32)#64, 96, 128, 16, 32, 32后6个 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:#两个辅助分类器 self.aux1 = InceptionAux(512, num_classes)#深度,类别个数 self.aux2 = InceptionAux(528, num_classes) self.avgpool = nn.AdaptiveAvgPool2d((1, 1))#自适应到1,1的高和宽,不用在意输入图像大小了 self.dropout = nn.Dropout(0.4) self.fc = nn.Linear(1024, num_classes) if init_weights:#如果有初始化的权重 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,训练模式时才用辅助分类器 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,训练模式时才用辅助分类器 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) class Inception(nn.Module):# Iception结构的模型,四个并行,单独训练,输出直接合并 def __init__(self, in_channels, ch1x1, ch3x3red, ch3x3, ch5x5red, ch5x5, pool_proj):#第一个是输入矩阵,后6个是对应六个模块要的,ch1*1就是#1*1,red是reduce super(Inception, self).__init__() self.branch1 = BasicConv2d(in_channels, ch1x1, kernel_size=1)#卷积核大小是1,步距也是1省略 self.branch2 = nn.Sequential(#Sequential方便合并,不用管了 BasicConv2d(in_channels, ch3x3red, kernel_size=1), BasicConv2d(ch3x3red, ch3x3, kernel_size=3, padding=1) #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)#pool_proj是卷积核个数 ) 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)#放在一个列表里,torch.cat合并,第二个参数1是在第一个维度进行合并(channels)(第0个是batch)class InceptionAux(nn.Module):#辅助分类器 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)#分类类别个数 def forward(self, x): # aux1: N x 512 x 14 x 14, aux2: N x 528 x 14 x 14 #输出 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)#从channel进行展平 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 x class BasicConv2d(nn.Module):##卷积与relu共同使用,不然很麻烦 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