self.se = nn.Sequential( nn.AdaptiveAvgPool2d(1), nn.Conv2d(in_channels=dw_channel, out_channels=dw_channel // 2, kernel_size=1, padding=0, stride=1, groups=1, bias=True), nn.ReLU(inplace=True), nn.Conv2d(in_channels=dw_channel // 2, out_channels=dw_channel, kernel_size=1, padding=0, stride=1, groups=1, bias=True), nn.Sigmoid()代码中文含义
时间: 2023-12-15 07:05:52 浏览: 36
这段代码定义了一个包含多个层的神经网络模型,其中包括:
1. `nn.AdaptiveAvgPool2d(1)`:自适应平均池化层,将输入的二维张量进行平均池化,输出形状为(1,1)的二维张量。
2. `nn.Conv2d(in_channels=dw_channel, out_channels=dw_channel // 2, kernel_size=1, padding=0, stride=1, groups=1, bias=True)`:卷积层,对输入的二维张量进行卷积操作,其中in_channels表示输入通道数,out_channels表示输出通道数,kernel_size表示卷积核大小,padding表示填充大小,stride表示步长,groups表示分组卷积数,bias表示是否使用偏置项。
3. `nn.ReLU(inplace=True)`:ReLU激活函数,对输入的张量进行非线性变换。
4. `nn.Conv2d(in_channels=dw_channel // 2, out_channels=dw_channel, kernel_size=1, padding=0, stride=1, groups=1, bias=True)`:卷积层,同上。
5. `nn.Sigmoid()`:Sigmoid激活函数,对输入的张量进行非线性变换,将输出值映射到0到1之间。
该代码段的中文含义是:定义了一个包含自适应平均池化、两个卷积层和两个激活函数的神经网络模型,用于进行特征提取和信息筛选。该模型的输出值被映射到0到1之间,用于表示输入特征的重要性。
相关问题
class BasicBlock2D(nn.Module): expansion = 1 def __init__(self, in_channels, out_channels, stride=1): super(BasicBlock2D, self).__init__() self.conv1 = nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=stride, padding=1, bias=False) self.bn1 = nn.BatchNorm2d(out_channels) self.conv2 = nn.Conv2d(out_channels, out_channels, kernel_size=3, stride=1, padding=1, bias=False) self.bn2 = nn.BatchNorm2d(out_channels) self.shortcut = nn.Sequential() if stride != 1 or in_channels != self.expansion * out_channels: self.shortcut = nn.Sequential( nn.Conv2d(in_channels, self.expansion * out_channels, kernel_size=1, stride=stride, bias=False), nn.BatchNorm2d(self.expansion * out_channels) ) def forward(self, x): out = F.relu(self.bn1(self.conv1(x))) out = self.bn2(self.conv2(out)) out += self.shortcut(x) out = F.relu(out) return out # 定义二维ResNet-18模型 class ResNet18_2D(nn.Module): def __init__(self, num_classes=1000): super(ResNet18_2D, self).__init__() self.in_channels = 64 self.conv1 = nn.Conv2d(1, 64, kernel_size=7, stride=2, padding=3, bias=False) self.bn1 = nn.BatchNorm2d(64) self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1) self.layer1 = self._make_layer(BasicBlock2D, 64, 2, stride=1) self.layer2 = self._make_layer(BasicBlock2D, 128, 2, stride=2) self.layer3 = self._make_layer(BasicBlock2D, 256, 2, stride=2) self.layer4 = self._make_layer(BasicBlock2D, 512, 2, stride=2) self.avgpool = nn.AdaptiveAvgPool2d((1, 1)) self.fc = nn.Linear(512 , 512) def _make_layer(self, block, out_channels, num_blocks, stride): layers = [] layers.append(block(self.in_channels, out_channels, stride)) self.in_channels = out_channels * block.expansion for _ in range(1, num_blocks): layers.append(block(self.in_channels, out_channels)) return nn.Sequential(*layers) def forward(self, x): out = F.relu(self.bn1(self.conv1(x))) out = self.maxpool(out) out = self.layer1(out) out = self.layer2(out) out = self.layer3(out) out = self.layer4(out) out = self.avgpool(out) # print(out.shape) out = out.view(out.size(0), -1) out = self.fc(out) return out改为用稀疏表示替换全连接层
为了用稀疏表示替换全连接层,需要先将特征图展平,然后使用稀疏矩阵与其进行乘法运算。
以下是修改后的代码:
```
import torch.sparse as sparse
class ResNet18_2D(nn.Module):
def __init__(self, num_classes=1000):
super(ResNet18_2D, self).__init__()
self.in_channels = 64
self.conv1 = nn.Conv2d(1, 64, kernel_size=7, stride=2, padding=3, bias=False)
self.bn1 = nn.BatchNorm2d(64)
self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.layer1 = self._make_layer(BasicBlock2D, 64, 2, stride=1)
self.layer2 = self._make_layer(BasicBlock2D, 128, 2, stride=2)
self.layer3 = self._make_layer(BasicBlock2D, 256, 2, stride=2)
self.layer4 = self._make_layer(BasicBlock2D, 512, 2, stride=2)
self.avgpool = nn.AdaptiveAvgPool2d((1, 1))
# 替换全连接层
self.fc = nn.Identity()
def _make_layer(self, block, out_channels, num_blocks, stride):
layers = []
layers.append(block(self.in_channels, out_channels, stride))
self.in_channels = out_channels * block.expansion
for _ in range(1, num_blocks):
layers.append(block(self.in_channels, out_channels))
return nn.Sequential(*layers)
def forward(self, x):
out = F.relu(self.bn1(self.conv1(x)))
out = self.maxpool(out)
out = self.layer1(out)
out = self.layer2(out)
out = self.layer3(out)
out = self.layer4(out)
out = self.avgpool(out)
out = out.view(out.size(0), -1)
# 使用稀疏矩阵与展平后的特征图进行乘法运算
out = sparse.mm(out, nn.Parameter(torch.randn(out.size(1), 512)))
return out
```
class EnhancedResidual(nn.Module): def __init__(self,in_c,out_c,fm_sz,net_type = 'ta'): super(EnhancedResidual,self).__init__() self.net_type = net_type self.conv1 = nn.Sequential( nn.Conv2d(in_channels = in_c,out_channels = in_c,kernel_size = 3,padding = 1), nn.BatchNorm2d(in_c), nn.ReLU(), ) self.conv2 = nn.Sequential( nn.Conv2d(in_channels = in_c,out_channels = out_c,kernel_size = 3,padding = 1), nn.BatchNorm2d(out_c), nn.ReLU(), ) self.botneck = nn.Conv2d(in_channels = in_c,out_channels = out_c,kernel_size = 1) self.pool = nn.MaxPool2d(kernel_size = 2,stride = 2) if net_type == 'ta': self.spa = SpatialAttention() self.ca = ChannelAttention(in_planes = in_c,ratio = in_c) self.sa = MultiHeadSelfAttention(in_c = in_c,out_c = in_c // 4,head_n = 4,fm_sz = fm_sz) elif net_type == 'sa': self.sa = MultiHeadSelfAttention(in_c = in_c,out_c = out_c // 4,head_n = 4,fm_sz = fm_sz) elif net_type == 'cbam': self.spa = SpatialAttention() self.ca = ChannelAttention(in_planes = in_c,ratio = in_c) 改写为tensorflow形式
把上述PyTorch代码转换成TensorFlow代码如下:
```python
import tensorflow as tf
class EnhancedResidual(tf.keras.layers.Layer):
def __init__(self, in_c, out_c, fm_sz, net_type='ta'):
super(EnhancedResidual, self).__init__()
self.net_type = net_type
self.conv1 = tf.keras.Sequential([
tf.keras.layers.Conv2D(filters=in_c, kernel_size=3, padding='same'),
tf.keras.layers.BatchNormalization(),
tf.keras.layers.ReLU()
])
self.conv2 = tf.keras.Sequential([
tf.keras.layers.Conv2D(filters=out_c, kernel_size=3, padding='same'),
tf.keras.layers.BatchNormalization(),
tf.keras.layers.ReLU()
])
self.botneck = tf.keras.layers.Conv2D(filters=out_c, kernel_size=1)
self.pool = tf.keras.layers.MaxPool2D(pool_size=2, strides=2)
if net_type == 'ta':
self.spa = SpatialAttention() # 需要自行定义SpatialAttention类
self.ca = ChannelAttention(in_planes=in_c, ratio=in_c) # 需要自行定义ChannelAttention类
self.sa = MultiHeadSelfAttention(in_c=in_c, out_c=in_c // 4, head_n=4, fm_sz=fm_sz) # 需要自行定义MultiHeadSelfAttention类
elif net_type == 'sa':
self.sa = MultiHeadSelfAttention(in_c=in_c, out_c=out_c // 4, head_n=4, fm_sz=fm_sz) # 需要自行定义MultiHeadSelfAttention类
elif net_type == 'cbam':
self.spa = SpatialAttention() # 需要自行定义SpatialAttention类
self.ca = ChannelAttention(in_planes=in_c, ratio=in_c) # 需要自行定义ChannelAttention类
def call(self, inputs):
x = self.conv1(inputs)
x = self.conv2(x)
shortcut = self.botneck(inputs)
x += shortcut
x = self.pool(x)
if self.net_type == 'ta':
x = self.spa(x) * x
x = self.ca(x) * x
x = self.sa(x) + x
elif self.net_type == 'sa':
x = self.sa(x) + x
elif self.net_type == 'cbam':
x = self.spa(x) * x
x = self.ca(x) * x
return x
```
需要注意的是,这里用到了一些自定义的类,如SpatialAttention、ChannelAttention和MultiHeadSelfAttention,需要根据具体情况自行实现。
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