Source code for mmselfsup.models.losses.beit_loss
# Copyright (c) OpenMMLab. All rights reserved.
from typing import Tuple, Union
import torch
from mmengine.model import BaseModule
from torch import nn
from mmselfsup.registry import MODELS
[docs]@MODELS.register_module()
class BEiTLoss(BaseModule):
"""Loss function for BEiT.
The BEiTLoss supports 2 diffenrent logits shared 1 target, like BEiT v2.
"""
def __init__(self) -> None:
super().__init__()
self.loss_cross_entropy = nn.CrossEntropyLoss()
[docs] def forward(self, logits: Union[Tuple[torch.Tensor], torch.Tensor],
target: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
"""Forward function of BEiT Loss.
Args:
logits (torch.Tensor): The outputs from the decoder.
target (torch.Tensor): The targets generated by dalle.
Returns:
Tuple[torch.Tensor, torch.Tensor]: The main loss.
"""
if isinstance(logits, torch.Tensor):
loss = self.loss_cross_entropy(logits, target)
return loss
elif isinstance(logits, Tuple):
loss_1 = self.loss_cross_entropy(logits[0], target)
loss_2 = self.loss_cross_entropy(logits[1], target)
return loss_1, loss_2