Thank you
Here is my data loading part
data_dir_train= 'cross_vali/train'
data_dir_val = 'cross_vali/val'
transform = transforms.Compose(
    [transforms.Resize(224),
     transforms.ToTensor()])
     #transforms.Normalize((76.02, 34.22, 37.86), (52.76, 6.61, 28.19))])

trainset = torchvision.datasets.ImageFolder(root=data_dir_train,
                                transform=transform)
trainloader = torch.utils.data.DataLoader(trainset, batch_size=4,
                                          shuffle=True, num_workers=2)

testset = torchvision.datasets.ImageFolder(root=data_dir_val,
                                       transform=transform)
testloader = torch.utils.data.DataLoader(testset, batch_size=4,
                                         shuffle=False, num_workers=2)


classes = ('MCIc','MCIs')