if h_out <= self.c: self.h_mat = nn.Parameter(torch.Tensor(1, h_out, 1, h_dim * self.k).normal_())怎么理解
时间: 2023-05-11 17:06:52 浏览: 66
这段代码是一个神经网络中的一部分,其中h_out是输出通道数,self.c是一个常数,h_dim是隐藏层的维度,self.k是卷积核的大小。如果h_out小于等于self.c,那么就会初始化一个形状为(1, h_out, 1, h_dim * self.k)的张量,并将其作为一个可训练的参数存储在self.h_mat中。这个张量是从正态分布中随机采样得到的。
相关问题
class ACmix(nn.Module): def __init__(self, in_planes, out_planes, kernel_att=7, head=4, kernel_conv=3, stride=1, dilation=1): super(ACmix, self).__init__() self.in_planes = in_planes self.out_planes = out_planes self.head = head self.kernel_att = kernel_att self.kernel_conv = kernel_conv self.stride = stride self.dilation = dilation self.rate1 = torch.nn.Parameter(torch.Tensor(1)) self.rate2 = torch.nn.Parameter(torch.Tensor(1)) self.head_dim = self.out_planes // self.head self.conv1 = nn.Conv2d(in_planes, out_planes, kernel_size=1) self.conv2 = nn.Conv2d(in_planes, out_planes, kernel_size=1) self.conv3 = nn.Conv2d(in_planes, out_planes, kernel_size=1) self.conv_p = nn.Conv2d(2, self.head_dim, kernel_size=1) self.padding_att = (self.dilation * (self.kernel_att - 1) + 1) // 2 self.pad_att = torch.nn.ReflectionPad2d(self.padding_att) self.unfold = nn.Unfold(kernel_size=self.kernel_att, padding=0, stride=self.stride) self.softmax = torch.nn.Softmax(dim=1) self.fc = nn.Conv2d(3 * self.head, self.kernel_conv * self.kernel_conv, kernel_size=1, bias=False) self.dep_conv = nn.Conv2d(self.kernel_conv * self.kernel_conv * self.head_dim, out_planes, kernel_size=self.kernel_conv, bias=True, groups=self.head_dim, padding=1, stride=stride) self.reset_parameters()逐行解释代码
这段代码是定义了一个名为ACmix的类,继承自PyTorch中的nn.Module。它包含了一些卷积、全连接、非线性激活函数等层,用于实现图像处理任务中的注意力机制和特征融合。
具体来说,逐行解释代码如下:
```
class ACmix(nn.Module):
def __init__(self, in_planes, out_planes, kernel_att=7, head=4, kernel_conv=3, stride=1, dilation=1):
super(ACmix, self).__init__()
```
定义ACmix类,其中包含了初始化函数__init__()。其中in_planes表示输入特征图的通道数,out_planes表示输出特征图的通道数,kernel_att表示注意力机制的卷积核大小,head表示注意力机制的头数,kernel_conv表示特征融合的卷积核大小,stride表示卷积的步长,dilation表示卷积的膨胀率。
```
self.in_planes = in_planes
self.out_planes = out_planes
self.head = head
self.kernel_att = kernel_att
self.kernel_conv = kernel_conv
self.stride = stride
self.dilation = dilation
self.rate1 = torch.nn.Parameter(torch.Tensor(1))
self.rate2 = torch.nn.Parameter(torch.Tensor(1))
self.head_dim = self.out_planes // self.head
```
将输入的参数保存到类的成员变量中,其中rate1和rate2是需要学习的参数,用于调整注意力机制中的权重。
```
self.conv1 = nn.Conv2d(in_planes, out_planes, kernel_size=1)
self.conv2 = nn.Conv2d(in_planes, out_planes, kernel_size=1)
self.conv3 = nn.Conv2d(in_planes, out_planes, kernel_size=1)
```
定义三个卷积层,其中conv1和conv2用于计算注意力机制,conv3用于特征融合。
```
self.conv_p = nn.Conv2d(2, self.head_dim, kernel_size=1)
```
定义一个卷积层,用于将注意力机制中的特征图转换为头数的通道数。
```
self.padding_att = (self.dilation * (self.kernel_att - 1) + 1) // 2
self.pad_att = torch.nn.ReflectionPad2d(self.padding_att)
self.unfold = nn.Unfold(kernel_size=self.kernel_att, padding=0, stride=self.stride)
self.softmax = torch.nn.Softmax(dim=1)
```
定义一些辅助层,其中padding_att表示注意力机制的填充大小,pad_att表示进行反射填充的层,unfold表示对特征图进行展开的层,softmax表示对展开后的特征图进行softmax操作的层。
```
self.fc = nn.Conv2d(3 * self.head, self.kernel_conv * self.kernel_conv, kernel_size=1, bias=False)
self.dep_conv = nn.Conv2d(self.kernel_conv * self.kernel_conv * self.head_dim, out_planes,
kernel_size=self.kernel_conv, bias=True, groups=self.head_dim, padding=1,
stride=stride)
```
定义特征融合的卷积层和深度可分离卷积层,其中fc层用于将展开后的特征图进行特征融合,dep_conv层用于将融合后的特征图进行输出。
```
self.reset_parameters()
```
初始化模型参数。
class Partial_conv3(nn.Module): def __init__(self, dim, n_div, forward): super().__init__() self.dim_conv3 = dim // n_div self.dim_untouched = dim - self.dim_conv3 self.partial_conv3 = nn.Conv2d(self.dim_conv3, self.dim_conv3, 3, 1, 1, bias=False) if forward == 'slicing': self.forward = self.forward_slicing elif forward == 'split_cat': self.forward = self.forward_split_cat else: raise NotImplementedError def forward_slicing(self, x: Tensor) -> Tensor: # only for inference x = x.clone() # !!! Keep the original input intact for the residual connection later x[:, :self.dim_conv3, :, :] = self.partial_conv3(x[:, :self.dim_conv3, :, :]) return x def forward_split_cat(self, x: Tensor) -> Tensor: x1, x2 = torch.split(x, [self.dim_conv3, self.dim_untouched], dim=1) x1 = self.partial_conv3(x1) x = torch.cat((x1, x2), 1) return x 在这段代码中插入全局平均池化做通道增强的模块
可以将全局平均池化放在每个 forward 函数的最后,对每个 channel 进行平均池化操作,然后将结果与未被改变的 channel 拼接起来,得到增强后的输出。修改后的代码如下:
```
class Partial_conv3(nn.Module):
def __init__(self, dim, n_div, forward):
super().__init__()
self.dim_conv3 = dim // n_div
self.dim_untouched = dim - self.dim_conv3
self.partial_conv3 = nn.Conv2d(self.dim_conv3, self.dim_conv3, 3, 1, 1, bias=False)
self.global_avg_pool = nn.AdaptiveAvgPool2d((1, 1)) # 添加全局平均池化层
if forward == 'slicing':
self.forward = self.forward_slicing
elif forward == 'split_cat':
self.forward = self.forward_split_cat
else:
raise NotImplementedError
def forward_slicing(self, x: Tensor) -> Tensor:
# only for inference
x = x.clone() # !!! Keep the original input intact for the residual connection later
x[:, :self.dim_conv3, :, :] = self.partial_conv3(x[:, :self.dim_conv3, :, :])
x[:, :self.dim_conv3, :, :] = self.global_avg_pool(x[:, :self.dim_conv3, :, :]) # 添加全局平均池化
x = torch.cat((x, x[:, self.dim_conv3:, :, :]), 1)
return x
def forward_split_cat(self, x: Tensor) -> Tensor:
x1, x2 = torch.split(x, [self.dim_conv3, self.dim_untouched], dim=1)
x1 = self.partial_conv3(x1)
x1 = self.global_avg_pool(x1) # 添加全局平均池化
x = torch.cat((x1, x2), 1)
return x
```