File size: 14,174 Bytes
617d388 |
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 |
# pylint: skip-file
# -----------------------------------------------------------------------------------
# SCUNet: Practical Blind Denoising via Swin-Conv-UNet and Data Synthesis, https://arxiv.org/abs/2203.13278
# Zhang, Kai and Li, Yawei and Liang, Jingyun and Cao, Jiezhang and Zhang, Yulun and Tang, Hao and Timofte, Radu and Van Gool, Luc
# -----------------------------------------------------------------------------------
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from einops.layers.torch import Rearrange
from .timm.drop import DropPath
from .timm.weight_init import trunc_normal_
# Borrowed from https://github.com/cszn/SCUNet/blob/main/models/network_scunet.py
class WMSA(nn.Module):
"""Self-attention module in Swin Transformer"""
def __init__(self, input_dim, output_dim, head_dim, window_size, type):
super(WMSA, self).__init__()
self.input_dim = input_dim
self.output_dim = output_dim
self.head_dim = head_dim
self.scale = self.head_dim**-0.5
self.n_heads = input_dim // head_dim
self.window_size = window_size
self.type = type
self.embedding_layer = nn.Linear(self.input_dim, 3 * self.input_dim, bias=True)
self.relative_position_params = nn.Parameter(
torch.zeros((2 * window_size - 1) * (2 * window_size - 1), self.n_heads)
)
# TODO recover
# self.relative_position_params = nn.Parameter(torch.zeros(self.n_heads, 2 * window_size - 1, 2 * window_size -1))
self.relative_position_params = nn.Parameter(
torch.zeros((2 * window_size - 1) * (2 * window_size - 1), self.n_heads)
)
self.linear = nn.Linear(self.input_dim, self.output_dim)
trunc_normal_(self.relative_position_params, std=0.02)
self.relative_position_params = torch.nn.Parameter(
self.relative_position_params.view(
2 * window_size - 1, 2 * window_size - 1, self.n_heads
)
.transpose(1, 2)
.transpose(0, 1)
)
def generate_mask(self, h, w, p, shift):
"""generating the mask of SW-MSA
Args:
shift: shift parameters in CyclicShift.
Returns:
attn_mask: should be (1 1 w p p),
"""
# supporting square.
attn_mask = torch.zeros(
h,
w,
p,
p,
p,
p,
dtype=torch.bool,
device=self.relative_position_params.device,
)
if self.type == "W":
return attn_mask
s = p - shift
attn_mask[-1, :, :s, :, s:, :] = True
attn_mask[-1, :, s:, :, :s, :] = True
attn_mask[:, -1, :, :s, :, s:] = True
attn_mask[:, -1, :, s:, :, :s] = True
attn_mask = rearrange(
attn_mask, "w1 w2 p1 p2 p3 p4 -> 1 1 (w1 w2) (p1 p2) (p3 p4)"
)
return attn_mask
def forward(self, x):
"""Forward pass of Window Multi-head Self-attention module.
Args:
x: input tensor with shape of [b h w c];
attn_mask: attention mask, fill -inf where the value is True;
Returns:
output: tensor shape [b h w c]
"""
if self.type != "W":
x = torch.roll(
x,
shifts=(-(self.window_size // 2), -(self.window_size // 2)),
dims=(1, 2),
)
x = rearrange(
x,
"b (w1 p1) (w2 p2) c -> b w1 w2 p1 p2 c",
p1=self.window_size,
p2=self.window_size,
)
h_windows = x.size(1)
w_windows = x.size(2)
# square validation
# assert h_windows == w_windows
x = rearrange(
x,
"b w1 w2 p1 p2 c -> b (w1 w2) (p1 p2) c",
p1=self.window_size,
p2=self.window_size,
)
qkv = self.embedding_layer(x)
q, k, v = rearrange(
qkv, "b nw np (threeh c) -> threeh b nw np c", c=self.head_dim
).chunk(3, dim=0)
sim = torch.einsum("hbwpc,hbwqc->hbwpq", q, k) * self.scale
# Adding learnable relative embedding
sim = sim + rearrange(self.relative_embedding(), "h p q -> h 1 1 p q")
# Using Attn Mask to distinguish different subwindows.
if self.type != "W":
attn_mask = self.generate_mask(
h_windows, w_windows, self.window_size, shift=self.window_size // 2
)
sim = sim.masked_fill_(attn_mask, float("-inf"))
probs = nn.functional.softmax(sim, dim=-1)
output = torch.einsum("hbwij,hbwjc->hbwic", probs, v)
output = rearrange(output, "h b w p c -> b w p (h c)")
output = self.linear(output)
output = rearrange(
output,
"b (w1 w2) (p1 p2) c -> b (w1 p1) (w2 p2) c",
w1=h_windows,
p1=self.window_size,
)
if self.type != "W":
output = torch.roll(
output,
shifts=(self.window_size // 2, self.window_size // 2),
dims=(1, 2),
)
return output
def relative_embedding(self):
cord = torch.tensor(
np.array(
[
[i, j]
for i in range(self.window_size)
for j in range(self.window_size)
]
)
)
relation = cord[:, None, :] - cord[None, :, :] + self.window_size - 1
# negative is allowed
return self.relative_position_params[
:, relation[:, :, 0].long(), relation[:, :, 1].long()
]
class Block(nn.Module):
def __init__(
self,
input_dim,
output_dim,
head_dim,
window_size,
drop_path,
type="W",
input_resolution=None,
):
"""SwinTransformer Block"""
super(Block, self).__init__()
self.input_dim = input_dim
self.output_dim = output_dim
assert type in ["W", "SW"]
self.type = type
if input_resolution <= window_size:
self.type = "W"
self.ln1 = nn.LayerNorm(input_dim)
self.msa = WMSA(input_dim, input_dim, head_dim, window_size, self.type)
self.drop_path = DropPath(drop_path) if drop_path > 0.0 else nn.Identity()
self.ln2 = nn.LayerNorm(input_dim)
self.mlp = nn.Sequential(
nn.Linear(input_dim, 4 * input_dim),
nn.GELU(),
nn.Linear(4 * input_dim, output_dim),
)
def forward(self, x):
x = x + self.drop_path(self.msa(self.ln1(x)))
x = x + self.drop_path(self.mlp(self.ln2(x)))
return x
class ConvTransBlock(nn.Module):
def __init__(
self,
conv_dim,
trans_dim,
head_dim,
window_size,
drop_path,
type="W",
input_resolution=None,
):
"""SwinTransformer and Conv Block"""
super(ConvTransBlock, self).__init__()
self.conv_dim = conv_dim
self.trans_dim = trans_dim
self.head_dim = head_dim
self.window_size = window_size
self.drop_path = drop_path
self.type = type
self.input_resolution = input_resolution
assert self.type in ["W", "SW"]
if self.input_resolution <= self.window_size:
self.type = "W"
self.trans_block = Block(
self.trans_dim,
self.trans_dim,
self.head_dim,
self.window_size,
self.drop_path,
self.type,
self.input_resolution,
)
self.conv1_1 = nn.Conv2d(
self.conv_dim + self.trans_dim,
self.conv_dim + self.trans_dim,
1,
1,
0,
bias=True,
)
self.conv1_2 = nn.Conv2d(
self.conv_dim + self.trans_dim,
self.conv_dim + self.trans_dim,
1,
1,
0,
bias=True,
)
self.conv_block = nn.Sequential(
nn.Conv2d(self.conv_dim, self.conv_dim, 3, 1, 1, bias=False),
nn.ReLU(True),
nn.Conv2d(self.conv_dim, self.conv_dim, 3, 1, 1, bias=False),
)
def forward(self, x):
conv_x, trans_x = torch.split(
self.conv1_1(x), (self.conv_dim, self.trans_dim), dim=1
)
conv_x = self.conv_block(conv_x) + conv_x
trans_x = Rearrange("b c h w -> b h w c")(trans_x)
trans_x = self.trans_block(trans_x)
trans_x = Rearrange("b h w c -> b c h w")(trans_x)
res = self.conv1_2(torch.cat((conv_x, trans_x), dim=1))
x = x + res
return x
class SCUNet(nn.Module):
def __init__(
self,
state_dict,
in_nc=3,
config=[4, 4, 4, 4, 4, 4, 4],
dim=64,
drop_path_rate=0.0,
input_resolution=256,
):
super(SCUNet, self).__init__()
self.model_arch = "SCUNet"
self.sub_type = "SR"
self.num_filters: int = 0
self.state = state_dict
self.config = config
self.dim = dim
self.head_dim = 32
self.window_size = 8
self.in_nc = in_nc
self.out_nc = self.in_nc
self.scale = 1
self.supports_fp16 = True
# drop path rate for each layer
dpr = [x.item() for x in torch.linspace(0, drop_path_rate, sum(config))]
self.m_head = [nn.Conv2d(in_nc, dim, 3, 1, 1, bias=False)]
begin = 0
self.m_down1 = [
ConvTransBlock(
dim // 2,
dim // 2,
self.head_dim,
self.window_size,
dpr[i + begin],
"W" if not i % 2 else "SW",
input_resolution,
)
for i in range(config[0])
] + [nn.Conv2d(dim, 2 * dim, 2, 2, 0, bias=False)]
begin += config[0]
self.m_down2 = [
ConvTransBlock(
dim,
dim,
self.head_dim,
self.window_size,
dpr[i + begin],
"W" if not i % 2 else "SW",
input_resolution // 2,
)
for i in range(config[1])
] + [nn.Conv2d(2 * dim, 4 * dim, 2, 2, 0, bias=False)]
begin += config[1]
self.m_down3 = [
ConvTransBlock(
2 * dim,
2 * dim,
self.head_dim,
self.window_size,
dpr[i + begin],
"W" if not i % 2 else "SW",
input_resolution // 4,
)
for i in range(config[2])
] + [nn.Conv2d(4 * dim, 8 * dim, 2, 2, 0, bias=False)]
begin += config[2]
self.m_body = [
ConvTransBlock(
4 * dim,
4 * dim,
self.head_dim,
self.window_size,
dpr[i + begin],
"W" if not i % 2 else "SW",
input_resolution // 8,
)
for i in range(config[3])
]
begin += config[3]
self.m_up3 = [
nn.ConvTranspose2d(8 * dim, 4 * dim, 2, 2, 0, bias=False),
] + [
ConvTransBlock(
2 * dim,
2 * dim,
self.head_dim,
self.window_size,
dpr[i + begin],
"W" if not i % 2 else "SW",
input_resolution // 4,
)
for i in range(config[4])
]
begin += config[4]
self.m_up2 = [
nn.ConvTranspose2d(4 * dim, 2 * dim, 2, 2, 0, bias=False),
] + [
ConvTransBlock(
dim,
dim,
self.head_dim,
self.window_size,
dpr[i + begin],
"W" if not i % 2 else "SW",
input_resolution // 2,
)
for i in range(config[5])
]
begin += config[5]
self.m_up1 = [
nn.ConvTranspose2d(2 * dim, dim, 2, 2, 0, bias=False),
] + [
ConvTransBlock(
dim // 2,
dim // 2,
self.head_dim,
self.window_size,
dpr[i + begin],
"W" if not i % 2 else "SW",
input_resolution,
)
for i in range(config[6])
]
self.m_tail = [nn.Conv2d(dim, in_nc, 3, 1, 1, bias=False)]
self.m_head = nn.Sequential(*self.m_head)
self.m_down1 = nn.Sequential(*self.m_down1)
self.m_down2 = nn.Sequential(*self.m_down2)
self.m_down3 = nn.Sequential(*self.m_down3)
self.m_body = nn.Sequential(*self.m_body)
self.m_up3 = nn.Sequential(*self.m_up3)
self.m_up2 = nn.Sequential(*self.m_up2)
self.m_up1 = nn.Sequential(*self.m_up1)
self.m_tail = nn.Sequential(*self.m_tail)
# self.apply(self._init_weights)
self.load_state_dict(state_dict, strict=True)
def check_image_size(self, x):
_, _, h, w = x.size()
mod_pad_h = (64 - h % 64) % 64
mod_pad_w = (64 - w % 64) % 64
x = F.pad(x, (0, mod_pad_w, 0, mod_pad_h), "reflect")
return x
def forward(self, x0):
h, w = x0.size()[-2:]
x0 = self.check_image_size(x0)
x1 = self.m_head(x0)
x2 = self.m_down1(x1)
x3 = self.m_down2(x2)
x4 = self.m_down3(x3)
x = self.m_body(x4)
x = self.m_up3(x + x4)
x = self.m_up2(x + x3)
x = self.m_up1(x + x2)
x = self.m_tail(x + x1)
x = x[:, :, :h, :w]
return x
def _init_weights(self, m):
if isinstance(m, nn.Linear):
trunc_normal_(m.weight, std=0.02)
if m.bias is not None:
nn.init.constant_(m.bias, 0)
elif isinstance(m, nn.LayerNorm):
nn.init.constant_(m.bias, 0)
nn.init.constant_(m.weight, 1.0)
|