File size: 5,849 Bytes
393d0cc |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 |
""" timm model adapter
Wraps timm (https://github.com/rwightman/pytorch-image-models) models for use as a vision tower in CLIP model (OpenCLIP).
"""
import logging
from collections import OrderedDict
import torch, sys
import torch.nn as nn
import timm
try:
import timm
from timm.models.layers import Mlp, to_2tuple
try:
# old timm imports < 0.8.1
from timm.models.layers.attention_pool2d import RotAttentionPool2d
from timm.models.layers.attention_pool2d import AttentionPool2d as AbsAttentionPool2d
except ImportError:
# new timm imports >= 0.8.1
from timm.layers import RotAttentionPool2d
from timm.layers import AttentionPool2d as AbsAttentionPool2d
except ImportError:
timm = None
from timm.models import create_model
from open_clip.utils import freeze_batch_norm_2d
from .vitamin import *
class TimmModel(nn.Module):
""" timm model adapter
"""
def __init__(
self,
model_name,
embed_dim,
image_size=224,
pool='avg',
proj='linear',
proj_bias=False,
drop=0.,
drop_path=None,
patch_drop=None,
pretrained=False,
):
super().__init__()
if timm is None:
raise RuntimeError("Please `pip install timm` to use timm models.")
self.image_size = to_2tuple(image_size)
# setup kwargs that may not be common across all models
timm_kwargs = {}
if drop_path is not None:
timm_kwargs['drop_path_rate'] = drop_path
if patch_drop is not None:
timm_kwargs['patch_drop_rate'] = patch_drop
custom_pool = pool in ('abs_attn', 'rot_attn')
if not proj and not custom_pool:
# use network classifier head as projection if no proj specified and no custom pooling used
self.trunk = timm.create_model(
model_name,
num_classes=embed_dim,
global_pool=pool,
pretrained=pretrained,
**timm_kwargs,
)
prev_chs = embed_dim
else:
self.trunk = timm.create_model(
model_name,
pretrained=pretrained,
**timm_kwargs,
)
feat_size = self.trunk.default_cfg.get('pool_size', None)
feature_ndim = 1 if not feat_size else 2
if custom_pool:
assert feature_ndim == 2
# if attn pooling used, remove both classifier and default pool
self.trunk.reset_classifier(0, global_pool='')
else:
# reset global pool if pool config set, otherwise leave as network default
reset_kwargs = dict(global_pool=pool) if pool else {}
self.trunk.reset_classifier(0, **reset_kwargs)
prev_chs = self.trunk.num_features
head_layers = OrderedDict()
# Add custom pooling to head
if pool == 'abs_attn':
head_layers['pool'] = AbsAttentionPool2d(prev_chs, feat_size=feat_size, out_features=embed_dim)
prev_chs = embed_dim
elif pool == 'rot_attn':
head_layers['pool'] = RotAttentionPool2d(prev_chs, out_features=embed_dim)
prev_chs = embed_dim
# NOTE attention pool ends with a projection layer, so proj should usually be set to '' if such pooling is used
if proj == 'linear':
head_layers['drop'] = nn.Dropout(drop)
head_layers['proj'] = nn.Linear(prev_chs, embed_dim, bias=proj_bias)
elif proj == 'mlp':
head_layers['mlp'] = Mlp(prev_chs, 2 * embed_dim, embed_dim, drop=(drop, 0), bias=(True, proj_bias))
else:
assert not proj, f'Unknown projection type {proj}.'
self.head = nn.Sequential(head_layers)
def lock(self, unlocked_groups=0, freeze_bn_stats=False):
""" lock modules
Args:
unlocked_groups (int): leave last n layer groups unlocked (default: 0)
"""
if not unlocked_groups:
# lock full model
for param in self.trunk.parameters():
param.requires_grad = False
if freeze_bn_stats:
freeze_batch_norm_2d(self.trunk)
else:
# NOTE: partial freeze requires latest timm (master) branch and is subject to change
try:
# FIXME import here until API stable and in an official release
from timm.models.helpers import group_parameters, group_modules
except ImportError:
raise RuntimeError(
'Please install latest timm `pip install git+https://github.com/rwightman/pytorch-image-models`')
matcher = self.trunk.group_matcher()
gparams = group_parameters(self.trunk, matcher)
max_layer_id = max(gparams.keys())
max_layer_id = max_layer_id - unlocked_groups
for group_idx in range(max_layer_id + 1):
group = gparams[group_idx]
for param in group:
self.trunk.get_parameter(param).requires_grad = False
if freeze_bn_stats:
gmodules = group_modules(self.trunk, matcher, reverse=True)
gmodules = {k for k, v in gmodules.items() if v <= max_layer_id}
freeze_batch_norm_2d(self.trunk, gmodules)
@torch.jit.ignore
def set_grad_checkpointing(self, enable=True):
try:
self.trunk.set_grad_checkpointing(enable)
except Exception as e:
logging.warning('grad checkpointing not supported for this timm image tower, continuing without...')
def forward(self, x):
x = self.trunk(x)
x = self.head(x)
return x
|