猫狗二分类添加一个拒绝类别,将猫狗预测概率小于阈值的预测样本归为第三类拒绝类别,pytorh代码
时间: 2024-05-02 13:16:15 浏览: 7
可以使用PyTorch实现猫狗二分类添加一个拒绝类别的方法如下:
```python
import torch
import torch.nn as nn
class CatDogClassifier(nn.Module):
def __init__(self, threshold):
super(CatDogClassifier, self).__init__()
self.threshold = threshold
self.conv1 = nn.Conv2d(3, 32, kernel_size=3, padding=1)
self.conv2 = nn.Conv2d(32, 64, kernel_size=3, padding=1)
self.pool = nn.MaxPool2d(2, 2)
self.fc1 = nn.Linear(64 * 56 * 56, 512)
self.fc2 = nn.Linear(512, 3)
self.dropout = nn.Dropout(0.5)
self.relu = nn.ReLU()
def forward(self, x):
x = self.pool(self.relu(self.conv1(x)))
x = self.pool(self.relu(self.conv2(x)))
x = x.view(-1, 64 * 56 * 56)
x = self.dropout(self.relu(self.fc1(x)))
x = self.fc2(x)
return x
def predict(self, x):
with torch.no_grad():
outputs = self.forward(x)
probs = torch.softmax(outputs, dim=1)
max_probs, preds = torch.max(probs, dim=1)
rejected = (max_probs < self.threshold)
preds[rejected] = 2
return preds
```
在模型中添加一个阈值参数threshold,当预测概率小于阈值时,将样本归为第三类拒绝类别。predict函数为模型的预测函数,首先通过softmax函数计算预测概率,然后选择概率最大的类别作为预测结果,但是当概率小于阈值时,将预测结果设置为第三类拒绝类别。