Note
You are reading the documentation for MMSelfSup 0.x, which will soon be deprecated by the end of 2022. We recommend you upgrade to MMSelfSup 1.0.0rc versions to enjoy fruitful new features and better performance brought by OpenMMLab 2.0. Check out the changelog, code and documentation of MMSelfSup 1.0.0rc for more details.
Source code for mmselfsup.models.algorithms.mae
# Copyright (c) OpenMMLab. All rights reserved.
from typing import Dict, Optional, Tuple
import torch
from ..builder import ALGORITHMS, build_backbone, build_head, build_neck
from .base import BaseModel
[docs]@ALGORITHMS.register_module()
class MAE(BaseModel):
"""MAE.
Implementation of `Masked Autoencoders Are Scalable Vision Learners
<https://arxiv.org/abs/2111.06377>`_.
Args:
backbone (dict): Config dict for encoder. Defaults to None.
neck (dict): Config dict for encoder. Defaults to None.
head (dict): Config dict for loss functions. Defaults to None.
init_cfg (dict, optional): Config dict for weight initialization.
Defaults to None.
"""
def __init__(self,
backbone: dict,
neck: dict,
head: dict,
init_cfg: Optional[dict] = None) -> None:
super().__init__(init_cfg)
assert backbone is not None
self.backbone = build_backbone(backbone)
assert neck is not None
self.neck = build_neck(neck)
self.neck.num_patches = self.backbone.num_patches
assert head is not None
self.head = build_head(head)
[docs] def extract_feat(self, img: torch.Tensor) -> Tuple[torch.Tensor]:
"""Function to extract features from backbone.
Args:
img (torch.Tensor): Input images of shape (N, C, H, W).
Returns:
Tuple[torch.Tensor]: backbone outputs.
"""
return self.backbone(img)
[docs] def forward_train(self, img: torch.Tensor,
**kwargs) -> Dict[str, torch.Tensor]:
"""Forward computation during training.
Args:
img (torch.Tensor): Input images of shape (N, C, H, W).
kwargs: Any keyword arguments to be used to forward.
Returns:
Dict[str, torch.Tensor]: A dictionary of loss components.
"""
latent, mask, ids_restore = self.backbone(img)
pred = self.neck(latent, ids_restore)
losses = self.head(img, pred, mask)
return losses
[docs] def forward_test(self, img: torch.Tensor,
**kwargs) -> Tuple[torch.Tensor, torch.Tensor]:
"""Forward computation during testing.
Args:
img (torch.Tensor): Input images of shape (N, C, H, W).
kwargs: Any keyword arguments to be used to forward.
Returns:
Tuple[torch.Tensor, torch.Tensor]: Output of model test.
- mask: Mask used to mask image.
- pred: The output of neck.
"""
latent, mask, ids_restore = self.backbone(img)
pred = self.neck(latent, ids_restore)
pred = self.head.unpatchify(pred)
pred = torch.einsum('nchw->nhwc', pred).detach().cpu()
mask = mask.detach()
mask = mask.unsqueeze(-1).repeat(1, 1, self.head.patch_size**2 *
3) # (N, H*W, p*p*3)
mask = self.head.unpatchify(mask) # 1 is removing, 0 is keeping
mask = torch.einsum('nchw->nhwc', mask).detach().cpu()
return mask, pred