我尝试在没有CUDA的情况下运行下面的代码来解决图像分割问题，因为我没有GPU。我已经使用pytorch在CPU上训练了我的模型，但在预测级别上，我得到了

AttributeError: 'NoneType' object has no attribute 'size'

下面是代码：

idx = 20
model.load_state_dict(torch.load('/content/best_model.pt'))
image, mask = validset[idx]
image = image.unsqueeze_(0)
print(type(image))
# logits_mask = model(image.to(DEVICE).unsqueeze(0)) # (c,h,w) -> (1,c,h,w)
logits_mask = model(image) # (c,h,w) py-> (1,c,h,w)

输出中产生的错误位于第8行：

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-56-edf3f0fae49c> in <module>
      6 print(type(image))
      7 # logits_mask = model(image.to(DEVICE).unsqueeze(0)) # (c,h,w) -> (1,c,h,w)
----> 8 logits_mask = model(image) # (c,h,w) py-> (1,c,h,w)
      9 
     10 pred_mask = torch.sigmoid(logits_mask)
3 frames
/usr/local/lib/python3.7/dist-packages/segmentation_models_pytorch/losses/dice.py in forward(self, y_pred, y_true)
     57     def forward(self, y_pred: torch.Tensor, y_true: torch.Tensor) -> torch.Tensor:
     58 
---> 59         assert y_true.size(0) == y_pred.size(0)
     60 
     61         if self.from_logits:
AttributeError: 'NoneType' object has no attribute 'size'