Source code for mmselfsup.models.losses.simmim_loss
# Copyright (c) OpenMMLab. All rights reserved.
import torch
from mmengine.model import BaseModule
from torch.nn import functional as F
from mmselfsup.registry import MODELS
[docs]@MODELS.register_module()
class SimMIMReconstructionLoss(BaseModule):
"""Loss function for MAE.
Compute the loss in masked region.
Args:
encoder_in_channels (int): Number of input channels for encoder.
"""
def __init__(self, encoder_in_channels: int) -> None:
super().__init__()
self.encoder_in_channels = encoder_in_channels
[docs] def forward(self, pred: torch.Tensor, target: torch.Tensor,
mask: torch.Tensor) -> torch.Tensor:
"""Forward function of MAE Loss.
Args:
pred (torch.Tensor): The reconstructed image.
target (torch.Tensor): The target image.
mask (torch.Tensor): The mask of the target image.
Returns:
torch.Tensor: The reconstruction loss.
"""
loss_rec = F.l1_loss(target, pred, reduction='none')
loss = (loss_rec * mask).sum() / (mask.sum() +
1e-5) / self.encoder_in_channels
return loss