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lora-scripts/sd-scripts/finetune/blip/vit.py
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| 1 |
+
'''
|
| 2 |
+
* Copyright (c) 2022, salesforce.com, inc.
|
| 3 |
+
* All rights reserved.
|
| 4 |
+
* SPDX-License-Identifier: BSD-3-Clause
|
| 5 |
+
* For full license text, see LICENSE.txt file in the repo root or https://opensource.org/licenses/BSD-3-Clause
|
| 6 |
+
* By Junnan Li
|
| 7 |
+
* Based on timm code base
|
| 8 |
+
* https://github.com/rwightman/pytorch-image-models/tree/master/timm
|
| 9 |
+
'''
|
| 10 |
+
|
| 11 |
+
import torch
|
| 12 |
+
import torch.nn as nn
|
| 13 |
+
import torch.nn.functional as F
|
| 14 |
+
from functools import partial
|
| 15 |
+
|
| 16 |
+
from timm.models.vision_transformer import _cfg, PatchEmbed
|
| 17 |
+
from timm.models.registry import register_model
|
| 18 |
+
from timm.models.layers import trunc_normal_, DropPath
|
| 19 |
+
from timm.models.helpers import named_apply, adapt_input_conv
|
| 20 |
+
|
| 21 |
+
from fairscale.nn.checkpoint.checkpoint_activations import checkpoint_wrapper
|
| 22 |
+
|
| 23 |
+
class Mlp(nn.Module):
|
| 24 |
+
""" MLP as used in Vision Transformer, MLP-Mixer and related networks
|
| 25 |
+
"""
|
| 26 |
+
def __init__(self, in_features, hidden_features=None, out_features=None, act_layer=nn.GELU, drop=0.):
|
| 27 |
+
super().__init__()
|
| 28 |
+
out_features = out_features or in_features
|
| 29 |
+
hidden_features = hidden_features or in_features
|
| 30 |
+
self.fc1 = nn.Linear(in_features, hidden_features)
|
| 31 |
+
self.act = act_layer()
|
| 32 |
+
self.fc2 = nn.Linear(hidden_features, out_features)
|
| 33 |
+
self.drop = nn.Dropout(drop)
|
| 34 |
+
|
| 35 |
+
def forward(self, x):
|
| 36 |
+
x = self.fc1(x)
|
| 37 |
+
x = self.act(x)
|
| 38 |
+
x = self.drop(x)
|
| 39 |
+
x = self.fc2(x)
|
| 40 |
+
x = self.drop(x)
|
| 41 |
+
return x
|
| 42 |
+
|
| 43 |
+
|
| 44 |
+
class Attention(nn.Module):
|
| 45 |
+
def __init__(self, dim, num_heads=8, qkv_bias=False, qk_scale=None, attn_drop=0., proj_drop=0.):
|
| 46 |
+
super().__init__()
|
| 47 |
+
self.num_heads = num_heads
|
| 48 |
+
head_dim = dim // num_heads
|
| 49 |
+
# NOTE scale factor was wrong in my original version, can set manually to be compat with prev weights
|
| 50 |
+
self.scale = qk_scale or head_dim ** -0.5
|
| 51 |
+
self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
|
| 52 |
+
self.attn_drop = nn.Dropout(attn_drop)
|
| 53 |
+
self.proj = nn.Linear(dim, dim)
|
| 54 |
+
self.proj_drop = nn.Dropout(proj_drop)
|
| 55 |
+
self.attn_gradients = None
|
| 56 |
+
self.attention_map = None
|
| 57 |
+
|
| 58 |
+
def save_attn_gradients(self, attn_gradients):
|
| 59 |
+
self.attn_gradients = attn_gradients
|
| 60 |
+
|
| 61 |
+
def get_attn_gradients(self):
|
| 62 |
+
return self.attn_gradients
|
| 63 |
+
|
| 64 |
+
def save_attention_map(self, attention_map):
|
| 65 |
+
self.attention_map = attention_map
|
| 66 |
+
|
| 67 |
+
def get_attention_map(self):
|
| 68 |
+
return self.attention_map
|
| 69 |
+
|
| 70 |
+
def forward(self, x, register_hook=False):
|
| 71 |
+
B, N, C = x.shape
|
| 72 |
+
qkv = self.qkv(x).reshape(B, N, 3, self.num_heads, C // self.num_heads).permute(2, 0, 3, 1, 4)
|
| 73 |
+
q, k, v = qkv[0], qkv[1], qkv[2] # make torchscript happy (cannot use tensor as tuple)
|
| 74 |
+
|
| 75 |
+
attn = (q @ k.transpose(-2, -1)) * self.scale
|
| 76 |
+
attn = attn.softmax(dim=-1)
|
| 77 |
+
attn = self.attn_drop(attn)
|
| 78 |
+
|
| 79 |
+
if register_hook:
|
| 80 |
+
self.save_attention_map(attn)
|
| 81 |
+
attn.register_hook(self.save_attn_gradients)
|
| 82 |
+
|
| 83 |
+
x = (attn @ v).transpose(1, 2).reshape(B, N, C)
|
| 84 |
+
x = self.proj(x)
|
| 85 |
+
x = self.proj_drop(x)
|
| 86 |
+
return x
|
| 87 |
+
|
| 88 |
+
|
| 89 |
+
class Block(nn.Module):
|
| 90 |
+
|
| 91 |
+
def __init__(self, dim, num_heads, mlp_ratio=4., qkv_bias=False, qk_scale=None, drop=0., attn_drop=0.,
|
| 92 |
+
drop_path=0., act_layer=nn.GELU, norm_layer=nn.LayerNorm, use_grad_checkpointing=False):
|
| 93 |
+
super().__init__()
|
| 94 |
+
self.norm1 = norm_layer(dim)
|
| 95 |
+
self.attn = Attention(
|
| 96 |
+
dim, num_heads=num_heads, qkv_bias=qkv_bias, qk_scale=qk_scale, attn_drop=attn_drop, proj_drop=drop)
|
| 97 |
+
# NOTE: drop path for stochastic depth, we shall see if this is better than dropout here
|
| 98 |
+
self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()
|
| 99 |
+
self.norm2 = norm_layer(dim)
|
| 100 |
+
mlp_hidden_dim = int(dim * mlp_ratio)
|
| 101 |
+
self.mlp = Mlp(in_features=dim, hidden_features=mlp_hidden_dim, act_layer=act_layer, drop=drop)
|
| 102 |
+
|
| 103 |
+
if use_grad_checkpointing:
|
| 104 |
+
self.attn = checkpoint_wrapper(self.attn)
|
| 105 |
+
self.mlp = checkpoint_wrapper(self.mlp)
|
| 106 |
+
|
| 107 |
+
def forward(self, x, register_hook=False):
|
| 108 |
+
x = x + self.drop_path(self.attn(self.norm1(x), register_hook=register_hook))
|
| 109 |
+
x = x + self.drop_path(self.mlp(self.norm2(x)))
|
| 110 |
+
return x
|
| 111 |
+
|
| 112 |
+
|
| 113 |
+
class VisionTransformer(nn.Module):
|
| 114 |
+
""" Vision Transformer
|
| 115 |
+
A PyTorch impl of : `An Image is Worth 16x16 Words: Transformers for Image Recognition at Scale` -
|
| 116 |
+
https://arxiv.org/abs/2010.11929
|
| 117 |
+
"""
|
| 118 |
+
def __init__(self, img_size=224, patch_size=16, in_chans=3, num_classes=1000, embed_dim=768, depth=12,
|
| 119 |
+
num_heads=12, mlp_ratio=4., qkv_bias=True, qk_scale=None, representation_size=None,
|
| 120 |
+
drop_rate=0., attn_drop_rate=0., drop_path_rate=0., norm_layer=None,
|
| 121 |
+
use_grad_checkpointing=False, ckpt_layer=0):
|
| 122 |
+
"""
|
| 123 |
+
Args:
|
| 124 |
+
img_size (int, tuple): input image size
|
| 125 |
+
patch_size (int, tuple): patch size
|
| 126 |
+
in_chans (int): number of input channels
|
| 127 |
+
num_classes (int): number of classes for classification head
|
| 128 |
+
embed_dim (int): embedding dimension
|
| 129 |
+
depth (int): depth of transformer
|
| 130 |
+
num_heads (int): number of attention heads
|
| 131 |
+
mlp_ratio (int): ratio of mlp hidden dim to embedding dim
|
| 132 |
+
qkv_bias (bool): enable bias for qkv if True
|
| 133 |
+
qk_scale (float): override default qk scale of head_dim ** -0.5 if set
|
| 134 |
+
representation_size (Optional[int]): enable and set representation layer (pre-logits) to this value if set
|
| 135 |
+
drop_rate (float): dropout rate
|
| 136 |
+
attn_drop_rate (float): attention dropout rate
|
| 137 |
+
drop_path_rate (float): stochastic depth rate
|
| 138 |
+
norm_layer: (nn.Module): normalization layer
|
| 139 |
+
"""
|
| 140 |
+
super().__init__()
|
| 141 |
+
self.num_features = self.embed_dim = embed_dim # num_features for consistency with other models
|
| 142 |
+
norm_layer = norm_layer or partial(nn.LayerNorm, eps=1e-6)
|
| 143 |
+
|
| 144 |
+
self.patch_embed = PatchEmbed(
|
| 145 |
+
img_size=img_size, patch_size=patch_size, in_chans=in_chans, embed_dim=embed_dim)
|
| 146 |
+
|
| 147 |
+
num_patches = self.patch_embed.num_patches
|
| 148 |
+
|
| 149 |
+
self.cls_token = nn.Parameter(torch.zeros(1, 1, embed_dim))
|
| 150 |
+
self.pos_embed = nn.Parameter(torch.zeros(1, num_patches + 1, embed_dim))
|
| 151 |
+
self.pos_drop = nn.Dropout(p=drop_rate)
|
| 152 |
+
|
| 153 |
+
dpr = [x.item() for x in torch.linspace(0, drop_path_rate, depth)] # stochastic depth decay rule
|
| 154 |
+
self.blocks = nn.ModuleList([
|
| 155 |
+
Block(
|
| 156 |
+
dim=embed_dim, num_heads=num_heads, mlp_ratio=mlp_ratio, qkv_bias=qkv_bias, qk_scale=qk_scale,
|
| 157 |
+
drop=drop_rate, attn_drop=attn_drop_rate, drop_path=dpr[i], norm_layer=norm_layer,
|
| 158 |
+
use_grad_checkpointing=(use_grad_checkpointing and i>=depth-ckpt_layer)
|
| 159 |
+
)
|
| 160 |
+
for i in range(depth)])
|
| 161 |
+
self.norm = norm_layer(embed_dim)
|
| 162 |
+
|
| 163 |
+
trunc_normal_(self.pos_embed, std=.02)
|
| 164 |
+
trunc_normal_(self.cls_token, std=.02)
|
| 165 |
+
self.apply(self._init_weights)
|
| 166 |
+
|
| 167 |
+
def _init_weights(self, m):
|
| 168 |
+
if isinstance(m, nn.Linear):
|
| 169 |
+
trunc_normal_(m.weight, std=.02)
|
| 170 |
+
if isinstance(m, nn.Linear) and m.bias is not None:
|
| 171 |
+
nn.init.constant_(m.bias, 0)
|
| 172 |
+
elif isinstance(m, nn.LayerNorm):
|
| 173 |
+
nn.init.constant_(m.bias, 0)
|
| 174 |
+
nn.init.constant_(m.weight, 1.0)
|
| 175 |
+
|
| 176 |
+
@torch.jit.ignore
|
| 177 |
+
def no_weight_decay(self):
|
| 178 |
+
return {'pos_embed', 'cls_token'}
|
| 179 |
+
|
| 180 |
+
def forward(self, x, register_blk=-1):
|
| 181 |
+
B = x.shape[0]
|
| 182 |
+
x = self.patch_embed(x)
|
| 183 |
+
|
| 184 |
+
cls_tokens = self.cls_token.expand(B, -1, -1) # stole cls_tokens impl from Phil Wang, thanks
|
| 185 |
+
x = torch.cat((cls_tokens, x), dim=1)
|
| 186 |
+
|
| 187 |
+
x = x + self.pos_embed[:,:x.size(1),:]
|
| 188 |
+
x = self.pos_drop(x)
|
| 189 |
+
|
| 190 |
+
for i,blk in enumerate(self.blocks):
|
| 191 |
+
x = blk(x, register_blk==i)
|
| 192 |
+
x = self.norm(x)
|
| 193 |
+
|
| 194 |
+
return x
|
| 195 |
+
|
| 196 |
+
@torch.jit.ignore()
|
| 197 |
+
def load_pretrained(self, checkpoint_path, prefix=''):
|
| 198 |
+
_load_weights(self, checkpoint_path, prefix)
|
| 199 |
+
|
| 200 |
+
|
| 201 |
+
@torch.no_grad()
|
| 202 |
+
def _load_weights(model: VisionTransformer, checkpoint_path: str, prefix: str = ''):
|
| 203 |
+
""" Load weights from .npz checkpoints for official Google Brain Flax implementation
|
| 204 |
+
"""
|
| 205 |
+
import numpy as np
|
| 206 |
+
|
| 207 |
+
def _n2p(w, t=True):
|
| 208 |
+
if w.ndim == 4 and w.shape[0] == w.shape[1] == w.shape[2] == 1:
|
| 209 |
+
w = w.flatten()
|
| 210 |
+
if t:
|
| 211 |
+
if w.ndim == 4:
|
| 212 |
+
w = w.transpose([3, 2, 0, 1])
|
| 213 |
+
elif w.ndim == 3:
|
| 214 |
+
w = w.transpose([2, 0, 1])
|
| 215 |
+
elif w.ndim == 2:
|
| 216 |
+
w = w.transpose([1, 0])
|
| 217 |
+
return torch.from_numpy(w)
|
| 218 |
+
|
| 219 |
+
w = np.load(checkpoint_path)
|
| 220 |
+
if not prefix and 'opt/target/embedding/kernel' in w:
|
| 221 |
+
prefix = 'opt/target/'
|
| 222 |
+
|
| 223 |
+
if hasattr(model.patch_embed, 'backbone'):
|
| 224 |
+
# hybrid
|
| 225 |
+
backbone = model.patch_embed.backbone
|
| 226 |
+
stem_only = not hasattr(backbone, 'stem')
|
| 227 |
+
stem = backbone if stem_only else backbone.stem
|
| 228 |
+
stem.conv.weight.copy_(adapt_input_conv(stem.conv.weight.shape[1], _n2p(w[f'{prefix}conv_root/kernel'])))
|
| 229 |
+
stem.norm.weight.copy_(_n2p(w[f'{prefix}gn_root/scale']))
|
| 230 |
+
stem.norm.bias.copy_(_n2p(w[f'{prefix}gn_root/bias']))
|
| 231 |
+
if not stem_only:
|
| 232 |
+
for i, stage in enumerate(backbone.stages):
|
| 233 |
+
for j, block in enumerate(stage.blocks):
|
| 234 |
+
bp = f'{prefix}block{i + 1}/unit{j + 1}/'
|
| 235 |
+
for r in range(3):
|
| 236 |
+
getattr(block, f'conv{r + 1}').weight.copy_(_n2p(w[f'{bp}conv{r + 1}/kernel']))
|
| 237 |
+
getattr(block, f'norm{r + 1}').weight.copy_(_n2p(w[f'{bp}gn{r + 1}/scale']))
|
| 238 |
+
getattr(block, f'norm{r + 1}').bias.copy_(_n2p(w[f'{bp}gn{r + 1}/bias']))
|
| 239 |
+
if block.downsample is not None:
|
| 240 |
+
block.downsample.conv.weight.copy_(_n2p(w[f'{bp}conv_proj/kernel']))
|
| 241 |
+
block.downsample.norm.weight.copy_(_n2p(w[f'{bp}gn_proj/scale']))
|
| 242 |
+
block.downsample.norm.bias.copy_(_n2p(w[f'{bp}gn_proj/bias']))
|
| 243 |
+
embed_conv_w = _n2p(w[f'{prefix}embedding/kernel'])
|
| 244 |
+
else:
|
| 245 |
+
embed_conv_w = adapt_input_conv(
|
| 246 |
+
model.patch_embed.proj.weight.shape[1], _n2p(w[f'{prefix}embedding/kernel']))
|
| 247 |
+
model.patch_embed.proj.weight.copy_(embed_conv_w)
|
| 248 |
+
model.patch_embed.proj.bias.copy_(_n2p(w[f'{prefix}embedding/bias']))
|
| 249 |
+
model.cls_token.copy_(_n2p(w[f'{prefix}cls'], t=False))
|
| 250 |
+
pos_embed_w = _n2p(w[f'{prefix}Transformer/posembed_input/pos_embedding'], t=False)
|
| 251 |
+
if pos_embed_w.shape != model.pos_embed.shape:
|
| 252 |
+
pos_embed_w = resize_pos_embed( # resize pos embedding when different size from pretrained weights
|
| 253 |
+
pos_embed_w, model.pos_embed, getattr(model, 'num_tokens', 1), model.patch_embed.grid_size)
|
| 254 |
+
model.pos_embed.copy_(pos_embed_w)
|
| 255 |
+
model.norm.weight.copy_(_n2p(w[f'{prefix}Transformer/encoder_norm/scale']))
|
| 256 |
+
model.norm.bias.copy_(_n2p(w[f'{prefix}Transformer/encoder_norm/bias']))
|
| 257 |
+
# if isinstance(model.head, nn.Linear) and model.head.bias.shape[0] == w[f'{prefix}head/bias'].shape[-1]:
|
| 258 |
+
# model.head.weight.copy_(_n2p(w[f'{prefix}head/kernel']))
|
| 259 |
+
# model.head.bias.copy_(_n2p(w[f'{prefix}head/bias']))
|
| 260 |
+
# if isinstance(getattr(model.pre_logits, 'fc', None), nn.Linear) and f'{prefix}pre_logits/bias' in w:
|
| 261 |
+
# model.pre_logits.fc.weight.copy_(_n2p(w[f'{prefix}pre_logits/kernel']))
|
| 262 |
+
# model.pre_logits.fc.bias.copy_(_n2p(w[f'{prefix}pre_logits/bias']))
|
| 263 |
+
for i, block in enumerate(model.blocks.children()):
|
| 264 |
+
block_prefix = f'{prefix}Transformer/encoderblock_{i}/'
|
| 265 |
+
mha_prefix = block_prefix + 'MultiHeadDotProductAttention_1/'
|
| 266 |
+
block.norm1.weight.copy_(_n2p(w[f'{block_prefix}LayerNorm_0/scale']))
|
| 267 |
+
block.norm1.bias.copy_(_n2p(w[f'{block_prefix}LayerNorm_0/bias']))
|
| 268 |
+
block.attn.qkv.weight.copy_(torch.cat([
|
| 269 |
+
_n2p(w[f'{mha_prefix}{n}/kernel'], t=False).flatten(1).T for n in ('query', 'key', 'value')]))
|
| 270 |
+
block.attn.qkv.bias.copy_(torch.cat([
|
| 271 |
+
_n2p(w[f'{mha_prefix}{n}/bias'], t=False).reshape(-1) for n in ('query', 'key', 'value')]))
|
| 272 |
+
block.attn.proj.weight.copy_(_n2p(w[f'{mha_prefix}out/kernel']).flatten(1))
|
| 273 |
+
block.attn.proj.bias.copy_(_n2p(w[f'{mha_prefix}out/bias']))
|
| 274 |
+
for r in range(2):
|
| 275 |
+
getattr(block.mlp, f'fc{r + 1}').weight.copy_(_n2p(w[f'{block_prefix}MlpBlock_3/Dense_{r}/kernel']))
|
| 276 |
+
getattr(block.mlp, f'fc{r + 1}').bias.copy_(_n2p(w[f'{block_prefix}MlpBlock_3/Dense_{r}/bias']))
|
| 277 |
+
block.norm2.weight.copy_(_n2p(w[f'{block_prefix}LayerNorm_2/scale']))
|
| 278 |
+
block.norm2.bias.copy_(_n2p(w[f'{block_prefix}LayerNorm_2/bias']))
|
| 279 |
+
|
| 280 |
+
|
| 281 |
+
def interpolate_pos_embed(pos_embed_checkpoint, visual_encoder):
|
| 282 |
+
# interpolate position embedding
|
| 283 |
+
embedding_size = pos_embed_checkpoint.shape[-1]
|
| 284 |
+
num_patches = visual_encoder.patch_embed.num_patches
|
| 285 |
+
num_extra_tokens = visual_encoder.pos_embed.shape[-2] - num_patches
|
| 286 |
+
# height (== width) for the checkpoint position embedding
|
| 287 |
+
orig_size = int((pos_embed_checkpoint.shape[-2] - num_extra_tokens) ** 0.5)
|
| 288 |
+
# height (== width) for the new position embedding
|
| 289 |
+
new_size = int(num_patches ** 0.5)
|
| 290 |
+
|
| 291 |
+
if orig_size!=new_size:
|
| 292 |
+
# class_token and dist_token are kept unchanged
|
| 293 |
+
extra_tokens = pos_embed_checkpoint[:, :num_extra_tokens]
|
| 294 |
+
# only the position tokens are interpolated
|
| 295 |
+
pos_tokens = pos_embed_checkpoint[:, num_extra_tokens:]
|
| 296 |
+
pos_tokens = pos_tokens.reshape(-1, orig_size, orig_size, embedding_size).permute(0, 3, 1, 2)
|
| 297 |
+
pos_tokens = torch.nn.functional.interpolate(
|
| 298 |
+
pos_tokens, size=(new_size, new_size), mode='bicubic', align_corners=False)
|
| 299 |
+
pos_tokens = pos_tokens.permute(0, 2, 3, 1).flatten(1, 2)
|
| 300 |
+
new_pos_embed = torch.cat((extra_tokens, pos_tokens), dim=1)
|
| 301 |
+
print('reshape position embedding from %d to %d'%(orig_size ** 2,new_size ** 2))
|
| 302 |
+
|
| 303 |
+
return new_pos_embed
|
| 304 |
+
else:
|
| 305 |
+
return pos_embed_checkpoint
|