43 lines
1.3 KiB
Python
43 lines
1.3 KiB
Python
# Copyright (c) OpenMMLab. All rights reserved.
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import torch.nn as nn
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from ..builder import BACKBONES
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from .base_backbone import BaseBackbone
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@BACKBONES.register_module()
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class LeNet5(BaseBackbone):
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"""`LeNet5 <https://en.wikipedia.org/wiki/LeNet>`_ backbone.
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The input for LeNet-5 is a 32×32 grayscale image.
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Args:
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num_classes (int): number of classes for classification.
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The default value is -1, which uses the backbone as
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a feature extractor without the top classifier.
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"""
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def __init__(self, num_classes=-1):
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super(LeNet5, self).__init__()
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self.num_classes = num_classes
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self.features = nn.Sequential(
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nn.Conv2d(1, 6, kernel_size=5, stride=1), nn.Tanh(),
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nn.AvgPool2d(kernel_size=2),
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nn.Conv2d(6, 16, kernel_size=5, stride=1), nn.Tanh(),
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nn.AvgPool2d(kernel_size=2),
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nn.Conv2d(16, 120, kernel_size=5, stride=1), nn.Tanh())
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if self.num_classes > 0:
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self.classifier = nn.Sequential(
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nn.Linear(120, 84),
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nn.Tanh(),
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nn.Linear(84, num_classes),
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)
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def forward(self, x):
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x = self.features(x)
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if self.num_classes > 0:
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x = self.classifier(x.squeeze())
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return (x, )
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