|
| 1 | +import torch |
| 2 | +import torch.nn as nn |
| 3 | +import torch.nn.functional as F |
| 4 | +from torch.utils import model_zoo |
| 5 | + |
| 6 | +__all__ = ['GoogLeNet', 'googlenet'] |
| 7 | + |
| 8 | +model_urls = { |
| 9 | + 'googlenet': '' |
| 10 | +} |
| 11 | + |
| 12 | + |
| 13 | +def googlenet(pretrained=False, **kwargs): |
| 14 | + r"""GoogLeNet (Inception v1) model architecture from |
| 15 | + `"Going Deeper with Convolutions" <http://arxiv.org/abs/1409.4842>`_. |
| 16 | + Args: |
| 17 | + pretrained (bool): If True, returns a model pre-trained on ImageNet |
| 18 | + """ |
| 19 | + if pretrained: |
| 20 | + model = GoogLeNet(**kwargs) |
| 21 | + model.load_state_dict(model_zoo.load_url(model_urls['googlenet'])) |
| 22 | + return model |
| 23 | + |
| 24 | + return GoogLeNet(**kwargs) |
| 25 | + |
| 26 | + |
| 27 | +class GoogLeNet(nn.Module): |
| 28 | + |
| 29 | + def __init__(self, num_classes=1000, aux_logits=True): |
| 30 | + super(GoogLeNet, self).__init__() |
| 31 | + self.aux_logits = aux_logits |
| 32 | + |
| 33 | + self.conv1 = BasicConv2d(3, 64, kernel_size=7, stride=2, padding=3) |
| 34 | + self.maxpool1 = nn.MaxPool2d(3, stride=2, padding=1) |
| 35 | + self.lrn1 = nn.LocalResponseNorm(5, alpha=0.0001) |
| 36 | + self.conv2 = BasicConv2d(64, 64, kernel_size=1) |
| 37 | + self.conv3 = BasicConv2d(64, 192, kernel_size=3, stride=1, padding=1) |
| 38 | + self.lrn2 = nn.LocalResponseNorm(5, alpha=0.0001) |
| 39 | + self.maxpool2 = nn.MaxPool2d(3, stride=2, padding=1) |
| 40 | + |
| 41 | + self.inception3a = Inception(192, 64, 96, 128, 16, 32, 32) |
| 42 | + self.inception3b = Inception(256, 128, 128, 192, 32, 96, 64) |
| 43 | + self.maxpool3 = nn.MaxPool2d(3, stride=2) |
| 44 | + |
| 45 | + self.inception4a = Inception(480, 192, 96, 208, 16, 48, 64) |
| 46 | + self.inception4b = Inception(512, 160, 112, 224, 24, 64, 64) |
| 47 | + self.inception4c = Inception(512, 128, 128, 256, 24, 64, 64) |
| 48 | + self.inception4d = Inception(512, 112, 144, 288, 32, 64, 64) |
| 49 | + self.inception4e = Inception(528, 256, 160, 320, 32, 128, 128) |
| 50 | + self.maxpool4 = nn.MaxPool2d(3, stride=2, padding=1) |
| 51 | + |
| 52 | + self.inception5a = Inception(832, 256, 160, 320, 32, 128, 128) |
| 53 | + self.inception5b = Inception(832, 384, 192, 384, 48, 128, 128) |
| 54 | + if aux_logits: |
| 55 | + self.aux1 = InceptionAux(512, num_classes) |
| 56 | + self.aux2 = InceptionAux(528, num_classes) |
| 57 | + self.avgpool = nn.AvgPool2d(7, stride=1) |
| 58 | + self.dropout = nn.Dropout(0.4) |
| 59 | + self.fc = nn.Linear(1024, num_classes) |
| 60 | + |
| 61 | + for m in self.modules(): |
| 62 | + if isinstance(m, nn.Conv2d) or isinstance(m, nn.Linear): |
| 63 | + import scipy.stats as stats |
| 64 | + X = stats.truncnorm(-2, 2, scale=0.01) |
| 65 | + values = torch.Tensor(X.rvs(m.weight.numel())) |
| 66 | + values = values.view(m.weight.size()) |
| 67 | + m.weight.data.copy_(values) |
| 68 | + |
| 69 | + def forward(self, x): |
| 70 | + x = self.conv1(x) |
| 71 | + x = self.maxpool1(x) |
| 72 | + x = self.lrn1(x) |
| 73 | + x = self.conv2(x) |
| 74 | + x = self.conv3(x) |
| 75 | + x = self.lrn2(x) |
| 76 | + x = self.maxpool2(x) |
| 77 | + |
| 78 | + x = self.inception3a(x) |
| 79 | + x = self.inception3b(x) |
| 80 | + x = self.maxpool3(x) |
| 81 | + x = self.inception4a(x) |
| 82 | + if self.training and self.aux_logits: |
| 83 | + aux1 = self.aux1(x) |
| 84 | + |
| 85 | + x = self.inception4b(x) |
| 86 | + x = self.inception4c(x) |
| 87 | + x = self.inception4d(x) |
| 88 | + if self.training and self.aux_logits: |
| 89 | + aux2 = self.aux2(x) |
| 90 | + |
| 91 | + x = self.inception4e(x) |
| 92 | + x = self.maxpool4(x) |
| 93 | + x = self.inception5a(x) |
| 94 | + x = self.inception5b(x) |
| 95 | + |
| 96 | + x = self.avgpool(x) |
| 97 | + x = x.view(x.size(0), -1) |
| 98 | + x = self.dropout(x) |
| 99 | + x = self.fc(x) |
| 100 | + if self.training and self.aux_logits: |
| 101 | + return aux1, aux2, x |
| 102 | + return x |
| 103 | + |
| 104 | + |
| 105 | +class Inception(nn.Module): |
| 106 | + |
| 107 | + def __init__(self, in_channels, ch1x1, ch3x3red, ch3x3, ch5x5red, ch5x5, pool_proj): |
| 108 | + super(Inception, self).__init__() |
| 109 | + |
| 110 | + self.branch1 = BasicConv2d(in_channels, ch1x1, kernel_size=1) |
| 111 | + |
| 112 | + self.branch2 = nn.Sequential( |
| 113 | + BasicConv2d(in_channels, ch3x3red, kernel_size=1, stride=1), |
| 114 | + BasicConv2d(ch3x3red, ch3x3, kernel_size=3, padding=1) |
| 115 | + ) |
| 116 | + |
| 117 | + self.branch3 = nn.Sequential( |
| 118 | + BasicConv2d(in_channels, ch5x5red, kernel_size=1), |
| 119 | + BasicConv2d(ch5x5red, ch5x5, kernel_size=5, padding=2) |
| 120 | + ) |
| 121 | + |
| 122 | + self.branch4 = nn.Sequential( |
| 123 | + nn.MaxPool2d(kernel_size=3, stride=1, padding=1), |
| 124 | + BasicConv2d(in_channels, pool_proj, kernel_size=1) |
| 125 | + ) |
| 126 | + |
| 127 | + def forward(self, x): |
| 128 | + branch1 = self.branch1(x) |
| 129 | + branch2 = self.branch2(x) |
| 130 | + branch3 = self.branch3(x) |
| 131 | + branch4 = self.branch4(x) |
| 132 | + |
| 133 | + outputs = [branch1, branch2, branch3, branch4] |
| 134 | + return torch.cat(outputs, 1) |
| 135 | + |
| 136 | + |
| 137 | +class InceptionAux(nn.Module): |
| 138 | + |
| 139 | + def __init__(self, in_channels, num_classes): |
| 140 | + super(InceptionAux, self).__init__() |
| 141 | + self.conv = BasicConv2d(in_channels, 128, kernel_size=1) |
| 142 | + |
| 143 | + self.fc1 = nn.Linear(128 * 3 * 3, 1024) |
| 144 | + self.fc2 = nn.Linear(1024, num_classes) |
| 145 | + |
| 146 | + def forward(self, x): |
| 147 | + x = F.avg_pool2d(x, kernel_size=5, stride=3) |
| 148 | + |
| 149 | + x = self.conv(x) |
| 150 | + x = x.view(x.size(0), -1) |
| 151 | + x = self.fc1(x) |
| 152 | + x = F.dropout(x, 0.7, training=self.training) |
| 153 | + x = self.fc2(x) |
| 154 | + |
| 155 | + return x |
| 156 | + |
| 157 | + |
| 158 | +class BasicConv2d(nn.Module): |
| 159 | + |
| 160 | + def __init__(self, in_channels, out_channels, **kwargs): |
| 161 | + super(BasicConv2d, self).__init__() |
| 162 | + self.conv = nn.Conv2d(in_channels, out_channels, **kwargs) |
| 163 | + |
| 164 | + def forward(self, x): |
| 165 | + x = self.conv(x) |
| 166 | + return F.relu(x, inplace=True) |
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