Files
2025-08-31 18:03:57 +01:00

106 lines
3.2 KiB
Python

from functools import partial
import timm.models.vision_transformer
import torch
import torch.nn as nn
import torch.nn.functional as F
from torch import Tensor
from timm.models.layers import trunc_normal_
class VisionTransformer(timm.models.vision_transformer.VisionTransformer):
""" Vision Transformer with support for global average pooling
"""
def __init__(self, global_pool=False, **kwargs):
super(VisionTransformer, self).__init__(**kwargs)
self.global_pool = global_pool
if self.global_pool:
norm_layer = kwargs['norm_layer']
embed_dim = kwargs['embed_dim']
self.fc_norm = norm_layer(embed_dim)
del self.norm # remove the original norm
def forward_features(self, x):
B = x.shape[0]
x = self.patch_embed(x)
cls_tokens = self.cls_token.expand(B, -1, -1) # stole cls_tokens impl from Phil Wang, thanks
x = torch.cat((cls_tokens, x), dim=1)
x = x + self.pos_embed
x = self.pos_drop(x)
for blk in self.blocks:
x = blk(x)
if self.global_pool:
x = x[:, 1:, :].mean(dim=1,keepdim=True) # global pool without cls token
outcome = self.fc_norm(x)
else:
x = self.norm(x)
outcome = x[:, 0]
return outcome
def RETFound_mae(**kwargs):
model = VisionTransformer(
patch_size=16, embed_dim=1024, depth=24, num_heads=16, mlp_ratio=4, qkv_bias=True,
norm_layer=partial(nn.LayerNorm, eps=1e-6), **kwargs)
return model
def Dinov2(args, **kwargs):
if args.model_arch == 'dinov2_vits14':
arch = 'vit_small_patch14_dinov2.lvd142m'
elif args.model_arch == 'dinov2_vitb14':
arch = 'vit_base_patch14_dinov2.lvd142m'
elif args.model_arch == 'dinov2_vitl14':
arch = 'vit_large_patch14_dinov2.lvd142m'
elif args.model_arch == 'dinov2_vitg14':
arch = 'vit_giant_patch14_dinov2.lvd142m'
else:
raise ValueError(f"Unknown model_arch '{args.model_arch}'. "
f"Expected one of: dinov2_vits14, dinov2_vitb14, dinov2_vitl14, dinov2_vitg14")
model = timm.create_model(
arch,
pretrained=True,
img_size=224,
**kwargs
)
return model
def RETFound_dinov2(args, **kwargs):
model = timm.create_model(
'vit_large_patch14_dinov2.lvd142m',
pretrained=True,
img_size=224,
**kwargs
)
return model
def Dinov3(args, **kwargs):
# Load ViT-L/16 backbone (hub model has `head = Identity` by default)
model = torch.hub.load(
repo_or_dir="facebookresearch/dinov3",
model=args.model_arch,
pretrained=False, # main() will load your checkpoint
trust_repo=True,
)
# Figure out feature dimension for the probe
feat_dim = getattr(model, "embed_dim", None) or getattr(model, "num_features", None)
model.head = nn.Linear(feat_dim, args.nb_classes)
trunc_normal_(model.head.weight, std=2e-5)
if model.head.bias is not None:
nn.init.zeros_(model.head.bias)
return model