Fine Tuning Pretrained Model MobileNet_V2 in Pytorch

Question

I am new to pyTorch and I am trying to Create a Classifier where I have around 10 kinds of Images Folder Dataset, for this task I am using Pretrained model( MobileNet_v2 ) but the problem is I am not able to change the FC layer of it. There is not model.fc attribute. Can anyone help me to do this. Thanks

Answer 1

From the MobileNet V2 source code it looks like this model has a sequential model called classifier in the end. Therefore, you should be able to change the final layer of the classifier like this:

import torch.nn as nn
import torchvision.models as models
model = models.mobilenet_v2()
model.classifier[1] = nn.Linear(model.last_channel, 10)

Unfortunately, I cannot test this code right now.
This is also a good reference, on how to finetune models.

Answer 2

Do something like below:

import torch
model = torch.hub.load('pytorch/vision', 'mobilenet_v2', pretrained=True)
print(model.classifier)

model.classifier[1] = torch.nn.Linear(in_features=model.classifier[1].in_features, out_features=10)
print(model.classifier)

output:

Sequential(
  (0): Dropout(p=0.2)
  (1): Linear(in_features=1280, out_features=1000, bias=True)
)
Sequential(
  (0): Dropout(p=0.2)
  (1): Linear(in_features=1280, out_features=10, bias=True)
)

Note: you would need torch >= 1.1.0 to use torch.hub.