self.avgpool1d = nn.AdaptiveAvgPool1d(1) self.avgpool2d = nn.AdaptiveAvgPool2d((1,1))

`nn.AdaptiveAvgPool1d(1)` 和 `nn.AdaptiveAvgPool2d((1,1))` 是PyTorch库中的动态池化层，用于自适应地调整输入张量的空间维度，以适应不同的输入大小。这两个函数的主要作用是将输入特征图（feature maps）沿着指定的方向进行平均聚合，从而减小其空间维度到一个固定大小（这里是1x1）。

1. 对于 `self.avgpool1d = nn.AdaptiveAvgPool1d(1)`，它会对一维输入（通常是时间序列数据）进行逐元素的平均池化，结果会得到一个新的向量，长度为1，保留了原始数据的全局信息。

2. 对于 `self.avgpool2d = nn.AdaptiveAvgPool2d((1,1))`，它适用于二维输入，如图像。这个函数会在每个通道上独立计算1x1区域的均值，因此即使输入图片的尺寸变化，输出也会保持一致的1x1大小，常用于提取特征图的全局描述符。

使用它们的示例：

# 假设我们有一个二维张量a作为输入
a = torch.rand(10, 3, 224, 224)  # (batch_size, channels, height, width)

# 对a进行1D和2D的自适应平均池化
avg_1d = self.avgpool1d(a)  # 输出形状：(batch_size, channels, 1)
avg_2d = self.avgpool2d(a)  # 输出形状：(batch_size, channels, 1, 1)

相关问题

更改import torch import torchvision.models as models import torch.nn as nn import torch.nn.functional as F class eca_Resnet50(nn.Module): def init(self): super().init() self.model = models.resnet50(pretrained=True) self.model.avgpool = nn.AdaptiveAvgPool2d((1,1)) self.model.fc = nn.Linear(2048, 1000) self.eca = ECA_Module(2048, 8) def forward(self, x): x = self.model.conv1(x) x = self.model.bn1(x) x = self.model.relu(x) x = self.model.maxpool(x) x = self.model.layer1(x) x = self.model.layer2(x) x = self.model.layer3(x) x = self.model.layer4(x) x = self.eca(x) x = self.model.avgpool(x) x = torch.flatten(x, 1) x = self.model.fc(x) return x class ECA_Module(nn.Module): def init(self, channel, k_size=3): super(ECA_Module, self).init() self.avg_pool = nn.AdaptiveAvgPool2d(1) self.conv = nn.Conv1d(1, 1, kernel_size=k_size, padding=(k_size - 1) // 2, bias=False) self.sigmoid = nn.Sigmoid() def forward(self, x): b, c, _, _ = x.size() y = self.avg_pool(x) y = self.conv(y.squeeze(-1).transpose(-1,-2)).transpose(-1,-2).unsqueeze(-1) y = self.sigmoid(y) return x * y.expand_as(x) class ImageDenoising(nn.Module): def init(self): super().init() self.model = eca_Resnet50() self.conv1 = nn.Conv2d(3, 64, kernel_size=3, stride=1, padding=1) self.conv2 = nn.Conv2d(64, 64, kernel_size=3, stride=1, padding=1) self.conv3 = nn.Conv2d(64, 3, kernel_size=3, stride=1, padding=1) def forward(self, x): x = self.conv1(x) x = F.relu(x) x = self.conv2(x) x = F.relu(x) x = self.conv3(x) x = F.relu(x) return x，使最后输出为[16,1,50,50,]。

更改后的代码如下：

import torch
import torchvision.models as models
import torch.nn as nn
import torch.nn.functional as F

class eca_Resnet50(nn.Module):
    def __init__(self):
        super().__init__()
        self.model = models.resnet50(pretrained=True)
        self.model.avgpool = nn.AdaptiveAvgPool2d((1,1))
        self.model.fc = nn.Linear(2048, 1000)
        self.eca = ECA_Module(2048, 8)

    def forward(self, x):
        x = self.model.conv1(x)
        x = self.model.bn1(x)
        x = self.model.relu(x)
        x = self.model.maxpool(x)
        x = self.model.layer1(x)
        x = self.model.layer2(x)
        x = self.model.layer3(x)
        x = self.model.layer4(x)
        x = self.eca(x)
        x = self.model.avgpool(x)
        x = torch.flatten(x, 1)
        x = self.model.fc(x)
        return x

class ECA_Module(nn.Module):
    def __init__(self, channel, k_size=3):
        super().__init__()
        self.avg_pool = nn.AdaptiveAvgPool2d(1)
        self.conv = nn.Conv1d(1, 1, kernel_size=k_size, padding=(k_size - 1) // 2, bias=False)
        self.sigmoid = nn.Sigmoid()

    def forward(self, x):
        b, c, _, _ = x.size()
        y = self.avg_pool(x)
        y = self.conv(y.squeeze(-1).transpose(-1,-2)).transpose(-1,-2).unsqueeze(-1)
        y = self.sigmoid(y)
        return x * y.expand_as(x)

class ImageDenoising(nn.Module):
    def __init__(self):
        super().__init__()
        self.model = eca_Resnet50()
        self.conv1 = nn.Conv2d(3, 64, kernel_size=3, stride=1, padding=1)
        self.conv2 = nn.Conv2d(64, 64, kernel_size=3, stride=1, padding=1)
        self.conv3 = nn.Conv2d(64, 1, kernel_size=3, stride=1, padding=1)

    def forward(self, x):
        x = self.conv1(x)
        x = F.relu(x)
        x = self.conv2(x)
        x = F.relu(x)
        x = self.conv3(x)
        x = F.relu(x)
        x = x.view(-1, 1, 50, 50)
        return x

在修改的过程中，主要是将最后一层卷积层的输出通道数改为 1，并在 forward 方法中添加了 x.view(-1, 1, 50, 50)，将输出的大小修改为 [16,1,50,50]。

更改import torch import torchvision.models as models import torch.nn as nn import torch.nn.functional as F class eca_Resnet50(nn.Module): def __init__(self): super().__init__() self.model = models.resnet50(pretrained=True) self.model.avgpool = nn.AdaptiveAvgPool2d((1,1)) self.model.fc = nn.Linear(2048, 1000) self.eca = ECA_Module(2048, 8) def forward(self, x): x = self.model.conv1(x) x = self.model.bn1(x) x = self.model.relu(x) x = self.model.maxpool(x) x = self.model.layer1(x) x = self.model.layer2(x) x = self.model.layer3(x) x = self.model.layer4(x) x = self.eca(x) x = self.model.avgpool(x) x = torch.flatten(x, 1) x = self.model.fc(x) return x class ECA_Module(nn.Module): def __init__(self, channel, k_size=3): super(ECA_Module, self).__init__() self.avg_pool = nn.AdaptiveAvgPool2d(1) self.conv = nn.Conv1d(1, 1, kernel_size=k_size, padding=(k_size - 1) // 2, bias=False) self.sigmoid = nn.Sigmoid() def forward(self, x): b, c, _, _ = x.size() y = self.avg_pool(x) y = self.conv(y.squeeze(-1).transpose(-1,-2)).transpose(-1,-2).unsqueeze(-1) y = self.sigmoid(y) return x * y.expand_as(x) class ImageDenoising(nn.Module): def __init__(self): super().__init__() self.model = eca_Resnet50() self.conv1 = nn.Conv2d(3, 64, kernel_size=3, stride=1, padding=1) self.conv2 = nn.Conv2d(64, 64, kernel_size=3, stride=1, padding=1) self.conv3 = nn.Conv2d(64, 3, kernel_size=3, stride=1, padding=1) def forward(self, x): x = self.conv1(x) x = F.relu(x) x = self.conv2(x) x = F.relu(x) x = self.conv3(x) x = F.relu(x) return x输出为[16,1,50,50]

很好，你已经成功地定义了一个带有 ECA 模块的 ResNet50，以及一个图像去噪模型 ImageDenoising，输出大小为 [16, 1, 50, 50]。在 ImageDenoising 的 forward 函数中，你首先将输入 x 传递给 conv1，然后对其进行 ReLU 激活。接下来，你将其传递给 conv2，并再次进行 ReLU 激活。最后，你将其传递给 conv3，再次进行 ReLU 激活，并返回输出 x。