Spaces:
Runtime error
Runtime error
File size: 26,617 Bytes
96a9519 |
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 |
# Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
#
# NVIDIA CORPORATION and its licensors retain all intellectual property
# and proprietary rights in and to this software, related documentation
# and any modifications thereto. Any use, reproduction, disclosure or
# distribution of this software and related documentation without an express
# license agreement from NVIDIA CORPORATION is strictly prohibited.
"""Augmentation pipeline from the paper
"Training Generative Adversarial Networks with Limited Data".
Matches the original implementation by Karras et al. at
https://github.com/NVlabs/stylegan2-ada/blob/main/training/augment.py"""
import numpy as np
import scipy.signal
import torch
from torch_utils import persistence
from torch_utils import misc
from torch_utils.ops import upfirdn2d
from torch_utils.ops import grid_sample_gradfix
from torch_utils.ops import conv2d_gradfix
#----------------------------------------------------------------------------
# Coefficients of various wavelet decomposition low-pass filters.
wavelets = {
'haar': [0.7071067811865476, 0.7071067811865476],
'db1': [0.7071067811865476, 0.7071067811865476],
'db2': [-0.12940952255092145, 0.22414386804185735, 0.836516303737469, 0.48296291314469025],
'db3': [0.035226291882100656, -0.08544127388224149, -0.13501102001039084, 0.4598775021193313, 0.8068915093133388, 0.3326705529509569],
'db4': [-0.010597401784997278, 0.032883011666982945, 0.030841381835986965, -0.18703481171888114, -0.02798376941698385, 0.6308807679295904, 0.7148465705525415, 0.23037781330885523],
'db5': [0.003335725285001549, -0.012580751999015526, -0.006241490213011705, 0.07757149384006515, -0.03224486958502952, -0.24229488706619015, 0.13842814590110342, 0.7243085284385744, 0.6038292697974729, 0.160102397974125],
'db6': [-0.00107730108499558, 0.004777257511010651, 0.0005538422009938016, -0.031582039318031156, 0.02752286553001629, 0.09750160558707936, -0.12976686756709563, -0.22626469396516913, 0.3152503517092432, 0.7511339080215775, 0.4946238903983854, 0.11154074335008017],
'db7': [0.0003537138000010399, -0.0018016407039998328, 0.00042957797300470274, 0.012550998556013784, -0.01657454163101562, -0.03802993693503463, 0.0806126091510659, 0.07130921926705004, -0.22403618499416572, -0.14390600392910627, 0.4697822874053586, 0.7291320908465551, 0.39653931948230575, 0.07785205408506236],
'db8': [-0.00011747678400228192, 0.0006754494059985568, -0.0003917403729959771, -0.00487035299301066, 0.008746094047015655, 0.013981027917015516, -0.04408825393106472, -0.01736930100202211, 0.128747426620186, 0.00047248457399797254, -0.2840155429624281, -0.015829105256023893, 0.5853546836548691, 0.6756307362980128, 0.3128715909144659, 0.05441584224308161],
'sym2': [-0.12940952255092145, 0.22414386804185735, 0.836516303737469, 0.48296291314469025],
'sym3': [0.035226291882100656, -0.08544127388224149, -0.13501102001039084, 0.4598775021193313, 0.8068915093133388, 0.3326705529509569],
'sym4': [-0.07576571478927333, -0.02963552764599851, 0.49761866763201545, 0.8037387518059161, 0.29785779560527736, -0.09921954357684722, -0.012603967262037833, 0.0322231006040427],
'sym5': [0.027333068345077982, 0.029519490925774643, -0.039134249302383094, 0.1993975339773936, 0.7234076904024206, 0.6339789634582119, 0.01660210576452232, -0.17532808990845047, -0.021101834024758855, 0.019538882735286728],
'sym6': [0.015404109327027373, 0.0034907120842174702, -0.11799011114819057, -0.048311742585633, 0.4910559419267466, 0.787641141030194, 0.3379294217276218, -0.07263752278646252, -0.021060292512300564, 0.04472490177066578, 0.0017677118642428036, -0.007800708325034148],
'sym7': [0.002681814568257878, -0.0010473848886829163, -0.01263630340325193, 0.03051551316596357, 0.0678926935013727, -0.049552834937127255, 0.017441255086855827, 0.5361019170917628, 0.767764317003164, 0.2886296317515146, -0.14004724044296152, -0.10780823770381774, 0.004010244871533663, 0.010268176708511255],
'sym8': [-0.0033824159510061256, -0.0005421323317911481, 0.03169508781149298, 0.007607487324917605, -0.1432942383508097, -0.061273359067658524, 0.4813596512583722, 0.7771857517005235, 0.3644418948353314, -0.05194583810770904, -0.027219029917056003, 0.049137179673607506, 0.003808752013890615, -0.01495225833704823, -0.0003029205147213668, 0.0018899503327594609],
}
#----------------------------------------------------------------------------
# Helpers for constructing transformation matrices.
def matrix(*rows, device=None):
assert all(len(row) == len(rows[0]) for row in rows)
elems = [x for row in rows for x in row]
ref = [x for x in elems if isinstance(x, torch.Tensor)]
if len(ref) == 0:
return misc.constant(np.asarray(rows), device=device)
assert device is None or device == ref[0].device
elems = [x if isinstance(x, torch.Tensor) else misc.constant(x, shape=ref[0].shape, device=ref[0].device) for x in elems]
return torch.stack(elems, dim=-1).reshape(ref[0].shape + (len(rows), -1))
def translate2d(tx, ty, **kwargs):
return matrix(
[1, 0, tx],
[0, 1, ty],
[0, 0, 1],
**kwargs)
def translate3d(tx, ty, tz, **kwargs):
return matrix(
[1, 0, 0, tx],
[0, 1, 0, ty],
[0, 0, 1, tz],
[0, 0, 0, 1],
**kwargs)
def scale2d(sx, sy, **kwargs):
return matrix(
[sx, 0, 0],
[0, sy, 0],
[0, 0, 1],
**kwargs)
def scale3d(sx, sy, sz, **kwargs):
return matrix(
[sx, 0, 0, 0],
[0, sy, 0, 0],
[0, 0, sz, 0],
[0, 0, 0, 1],
**kwargs)
def rotate2d(theta, **kwargs):
return matrix(
[torch.cos(theta), torch.sin(-theta), 0],
[torch.sin(theta), torch.cos(theta), 0],
[0, 0, 1],
**kwargs)
def rotate3d(v, theta, **kwargs):
vx = v[..., 0]; vy = v[..., 1]; vz = v[..., 2]
s = torch.sin(theta); c = torch.cos(theta); cc = 1 - c
return matrix(
[vx*vx*cc+c, vx*vy*cc-vz*s, vx*vz*cc+vy*s, 0],
[vy*vx*cc+vz*s, vy*vy*cc+c, vy*vz*cc-vx*s, 0],
[vz*vx*cc-vy*s, vz*vy*cc+vx*s, vz*vz*cc+c, 0],
[0, 0, 0, 1],
**kwargs)
def translate2d_inv(tx, ty, **kwargs):
return translate2d(-tx, -ty, **kwargs)
def scale2d_inv(sx, sy, **kwargs):
return scale2d(1 / sx, 1 / sy, **kwargs)
def rotate2d_inv(theta, **kwargs):
return rotate2d(-theta, **kwargs)
#----------------------------------------------------------------------------
# Versatile image augmentation pipeline from the paper
# "Training Generative Adversarial Networks with Limited Data".
#
# All augmentations are disabled by default; individual augmentations can
# be enabled by setting their probability multipliers to 1.
@persistence.persistent_class
class AugmentPipe(torch.nn.Module):
def __init__(self,
xflip=0, rotate90=0, xint=0, xint_max=0.125,
scale=0, rotate=0, aniso=0, xfrac=0, scale_std=0.2, rotate_max=1, aniso_std=0.2, xfrac_std=0.125,
brightness=0, contrast=0, lumaflip=0, hue=0, saturation=0, brightness_std=0.2, contrast_std=0.5, hue_max=1, saturation_std=1,
imgfilter=0, imgfilter_bands=[1,1,1,1], imgfilter_std=1,
noise=0, cutout=0, noise_std=0.1, cutout_size=0.5,
):
super().__init__()
self.register_buffer('p', torch.ones([])) # Overall multiplier for augmentation probability.
# Pixel blitting.
self.xflip = float(xflip) # Probability multiplier for x-flip.
self.rotate90 = float(rotate90) # Probability multiplier for 90 degree rotations.
self.xint = float(xint) # Probability multiplier for integer translation.
self.xint_max = float(xint_max) # Range of integer translation, relative to image dimensions.
# General geometric transformations.
self.scale = float(scale) # Probability multiplier for isotropic scaling.
self.rotate = float(rotate) # Probability multiplier for arbitrary rotation.
self.aniso = float(aniso) # Probability multiplier for anisotropic scaling.
self.xfrac = float(xfrac) # Probability multiplier for fractional translation.
self.scale_std = float(scale_std) # Log2 standard deviation of isotropic scaling.
self.rotate_max = float(rotate_max) # Range of arbitrary rotation, 1 = full circle.
self.aniso_std = float(aniso_std) # Log2 standard deviation of anisotropic scaling.
self.xfrac_std = float(xfrac_std) # Standard deviation of frational translation, relative to image dimensions.
# Color transformations.
self.brightness = float(brightness) # Probability multiplier for brightness.
self.contrast = float(contrast) # Probability multiplier for contrast.
self.lumaflip = float(lumaflip) # Probability multiplier for luma flip.
self.hue = float(hue) # Probability multiplier for hue rotation.
self.saturation = float(saturation) # Probability multiplier for saturation.
self.brightness_std = float(brightness_std) # Standard deviation of brightness.
self.contrast_std = float(contrast_std) # Log2 standard deviation of contrast.
self.hue_max = float(hue_max) # Range of hue rotation, 1 = full circle.
self.saturation_std = float(saturation_std) # Log2 standard deviation of saturation.
# Image-space filtering.
self.imgfilter = float(imgfilter) # Probability multiplier for image-space filtering.
self.imgfilter_bands = list(imgfilter_bands) # Probability multipliers for individual frequency bands.
self.imgfilter_std = float(imgfilter_std) # Log2 standard deviation of image-space filter amplification.
# Image-space corruptions.
self.noise = float(noise) # Probability multiplier for additive RGB noise.
self.cutout = float(cutout) # Probability multiplier for cutout.
self.noise_std = float(noise_std) # Standard deviation of additive RGB noise.
self.cutout_size = float(cutout_size) # Size of the cutout rectangle, relative to image dimensions.
# Setup orthogonal lowpass filter for geometric augmentations.
self.register_buffer('Hz_geom', upfirdn2d.setup_filter(wavelets['sym6']))
# Construct filter bank for image-space filtering.
Hz_lo = np.asarray(wavelets['sym2']) # H(z)
Hz_hi = Hz_lo * ((-1) ** np.arange(Hz_lo.size)) # H(-z)
Hz_lo2 = np.convolve(Hz_lo, Hz_lo[::-1]) / 2 # H(z) * H(z^-1) / 2
Hz_hi2 = np.convolve(Hz_hi, Hz_hi[::-1]) / 2 # H(-z) * H(-z^-1) / 2
Hz_fbank = np.eye(4, 1) # Bandpass(H(z), b_i)
for i in range(1, Hz_fbank.shape[0]):
Hz_fbank = np.dstack([Hz_fbank, np.zeros_like(Hz_fbank)]).reshape(Hz_fbank.shape[0], -1)[:, :-1]
Hz_fbank = scipy.signal.convolve(Hz_fbank, [Hz_lo2])
Hz_fbank[i, (Hz_fbank.shape[1] - Hz_hi2.size) // 2 : (Hz_fbank.shape[1] + Hz_hi2.size) // 2] += Hz_hi2
self.register_buffer('Hz_fbank', torch.as_tensor(Hz_fbank, dtype=torch.float32))
def forward(self, images, debug_percentile=None):
assert isinstance(images, torch.Tensor) and images.ndim == 4
batch_size, num_channels, height, width = images.shape
device = images.device
if debug_percentile is not None:
debug_percentile = torch.as_tensor(debug_percentile, dtype=torch.float32, device=device)
# -------------------------------------
# Select parameters for pixel blitting.
# -------------------------------------
# Initialize inverse homogeneous 2D transform: G_inv @ pixel_out ==> pixel_in
I_3 = torch.eye(3, device=device)
G_inv = I_3
# Apply x-flip with probability (xflip * strength).
if self.xflip > 0:
i = torch.floor(torch.rand([batch_size], device=device) * 2)
i = torch.where(torch.rand([batch_size], device=device) < self.xflip * self.p, i, torch.zeros_like(i))
if debug_percentile is not None:
i = torch.full_like(i, torch.floor(debug_percentile * 2))
G_inv = G_inv @ scale2d_inv(1 - 2 * i, 1)
# Apply 90 degree rotations with probability (rotate90 * strength).
if self.rotate90 > 0:
i = torch.floor(torch.rand([batch_size], device=device) * 4)
i = torch.where(torch.rand([batch_size], device=device) < self.rotate90 * self.p, i, torch.zeros_like(i))
if debug_percentile is not None:
i = torch.full_like(i, torch.floor(debug_percentile * 4))
G_inv = G_inv @ rotate2d_inv(-np.pi / 2 * i)
# Apply integer translation with probability (xint * strength).
if self.xint > 0:
t = (torch.rand([batch_size, 2], device=device) * 2 - 1) * self.xint_max
t = torch.where(torch.rand([batch_size, 1], device=device) < self.xint * self.p, t, torch.zeros_like(t))
if debug_percentile is not None:
t = torch.full_like(t, (debug_percentile * 2 - 1) * self.xint_max)
G_inv = G_inv @ translate2d_inv(torch.round(t[:,0] * width), torch.round(t[:,1] * height))
# --------------------------------------------------------
# Select parameters for general geometric transformations.
# --------------------------------------------------------
# Apply isotropic scaling with probability (scale * strength).
if self.scale > 0:
s = torch.exp2(torch.randn([batch_size], device=device) * self.scale_std)
s = torch.where(torch.rand([batch_size], device=device) < self.scale * self.p, s, torch.ones_like(s))
if debug_percentile is not None:
s = torch.full_like(s, torch.exp2(torch.erfinv(debug_percentile * 2 - 1) * self.scale_std))
G_inv = G_inv @ scale2d_inv(s, s)
# Apply pre-rotation with probability p_rot.
p_rot = 1 - torch.sqrt((1 - self.rotate * self.p).clamp(0, 1)) # P(pre OR post) = p
if self.rotate > 0:
theta = (torch.rand([batch_size], device=device) * 2 - 1) * np.pi * self.rotate_max
theta = torch.where(torch.rand([batch_size], device=device) < p_rot, theta, torch.zeros_like(theta))
if debug_percentile is not None:
theta = torch.full_like(theta, (debug_percentile * 2 - 1) * np.pi * self.rotate_max)
G_inv = G_inv @ rotate2d_inv(-theta) # Before anisotropic scaling.
# Apply anisotropic scaling with probability (aniso * strength).
if self.aniso > 0:
s = torch.exp2(torch.randn([batch_size], device=device) * self.aniso_std)
s = torch.where(torch.rand([batch_size], device=device) < self.aniso * self.p, s, torch.ones_like(s))
if debug_percentile is not None:
s = torch.full_like(s, torch.exp2(torch.erfinv(debug_percentile * 2 - 1) * self.aniso_std))
G_inv = G_inv @ scale2d_inv(s, 1 / s)
# Apply post-rotation with probability p_rot.
if self.rotate > 0:
theta = (torch.rand([batch_size], device=device) * 2 - 1) * np.pi * self.rotate_max
theta = torch.where(torch.rand([batch_size], device=device) < p_rot, theta, torch.zeros_like(theta))
if debug_percentile is not None:
theta = torch.zeros_like(theta)
G_inv = G_inv @ rotate2d_inv(-theta) # After anisotropic scaling.
# Apply fractional translation with probability (xfrac * strength).
if self.xfrac > 0:
t = torch.randn([batch_size, 2], device=device) * self.xfrac_std
t = torch.where(torch.rand([batch_size, 1], device=device) < self.xfrac * self.p, t, torch.zeros_like(t))
if debug_percentile is not None:
t = torch.full_like(t, torch.erfinv(debug_percentile * 2 - 1) * self.xfrac_std)
G_inv = G_inv @ translate2d_inv(t[:,0] * width, t[:,1] * height)
# ----------------------------------
# Execute geometric transformations.
# ----------------------------------
# Execute if the transform is not identity.
if G_inv is not I_3:
# Calculate padding.
cx = (width - 1) / 2
cy = (height - 1) / 2
cp = matrix([-cx, -cy, 1], [cx, -cy, 1], [cx, cy, 1], [-cx, cy, 1], device=device) # [idx, xyz]
cp = G_inv @ cp.t() # [batch, xyz, idx]
Hz_pad = self.Hz_geom.shape[0] // 4
margin = cp[:, :2, :].permute(1, 0, 2).flatten(1) # [xy, batch * idx]
margin = torch.cat([-margin, margin]).max(dim=1).values # [x0, y0, x1, y1]
margin = margin + misc.constant([Hz_pad * 2 - cx, Hz_pad * 2 - cy] * 2, device=device)
margin = margin.max(misc.constant([0, 0] * 2, device=device))
margin = margin.min(misc.constant([width-1, height-1] * 2, device=device))
mx0, my0, mx1, my1 = margin.ceil().to(torch.int32)
# Pad image and adjust origin.
images = torch.nn.functional.pad(input=images, pad=[mx0,mx1,my0,my1], mode='reflect')
G_inv = translate2d((mx0 - mx1) / 2, (my0 - my1) / 2) @ G_inv
# Upsample.
images = upfirdn2d.upsample2d(x=images, f=self.Hz_geom, up=2)
G_inv = scale2d(2, 2, device=device) @ G_inv @ scale2d_inv(2, 2, device=device)
G_inv = translate2d(-0.5, -0.5, device=device) @ G_inv @ translate2d_inv(-0.5, -0.5, device=device)
# Execute transformation.
shape = [batch_size, num_channels, (height + Hz_pad * 2) * 2, (width + Hz_pad * 2) * 2]
G_inv = scale2d(2 / images.shape[3], 2 / images.shape[2], device=device) @ G_inv @ scale2d_inv(2 / shape[3], 2 / shape[2], device=device)
grid = torch.nn.functional.affine_grid(theta=G_inv[:,:2,:], size=shape, align_corners=False)
images = grid_sample_gradfix.grid_sample(images, grid)
# Downsample and crop.
images = upfirdn2d.downsample2d(x=images, f=self.Hz_geom, down=2, padding=-Hz_pad*2, flip_filter=True)
# --------------------------------------------
# Select parameters for color transformations.
# --------------------------------------------
# Initialize homogeneous 3D transformation matrix: C @ color_in ==> color_out
I_4 = torch.eye(4, device=device)
C = I_4
# Apply brightness with probability (brightness * strength).
if self.brightness > 0:
b = torch.randn([batch_size], device=device) * self.brightness_std
b = torch.where(torch.rand([batch_size], device=device) < self.brightness * self.p, b, torch.zeros_like(b))
if debug_percentile is not None:
b = torch.full_like(b, torch.erfinv(debug_percentile * 2 - 1) * self.brightness_std)
C = translate3d(b, b, b) @ C
# Apply contrast with probability (contrast * strength).
if self.contrast > 0:
c = torch.exp2(torch.randn([batch_size], device=device) * self.contrast_std)
c = torch.where(torch.rand([batch_size], device=device) < self.contrast * self.p, c, torch.ones_like(c))
if debug_percentile is not None:
c = torch.full_like(c, torch.exp2(torch.erfinv(debug_percentile * 2 - 1) * self.contrast_std))
C = scale3d(c, c, c) @ C
# Apply luma flip with probability (lumaflip * strength).
v = misc.constant(np.asarray([1, 1, 1, 0]) / np.sqrt(3), device=device) # Luma axis.
if self.lumaflip > 0:
i = torch.floor(torch.rand([batch_size, 1, 1], device=device) * 2)
i = torch.where(torch.rand([batch_size, 1, 1], device=device) < self.lumaflip * self.p, i, torch.zeros_like(i))
if debug_percentile is not None:
i = torch.full_like(i, torch.floor(debug_percentile * 2))
C = (I_4 - 2 * v.ger(v) * i) @ C # Householder reflection.
# Apply hue rotation with probability (hue * strength).
if self.hue > 0 and num_channels > 1:
theta = (torch.rand([batch_size], device=device) * 2 - 1) * np.pi * self.hue_max
theta = torch.where(torch.rand([batch_size], device=device) < self.hue * self.p, theta, torch.zeros_like(theta))
if debug_percentile is not None:
theta = torch.full_like(theta, (debug_percentile * 2 - 1) * np.pi * self.hue_max)
C = rotate3d(v, theta) @ C # Rotate around v.
# Apply saturation with probability (saturation * strength).
if self.saturation > 0 and num_channels > 1:
s = torch.exp2(torch.randn([batch_size, 1, 1], device=device) * self.saturation_std)
s = torch.where(torch.rand([batch_size, 1, 1], device=device) < self.saturation * self.p, s, torch.ones_like(s))
if debug_percentile is not None:
s = torch.full_like(s, torch.exp2(torch.erfinv(debug_percentile * 2 - 1) * self.saturation_std))
C = (v.ger(v) + (I_4 - v.ger(v)) * s) @ C
# ------------------------------
# Execute color transformations.
# ------------------------------
# Execute if the transform is not identity.
if C is not I_4:
images = images.reshape([batch_size, num_channels, height * width])
if num_channels == 3:
images = C[:, :3, :3] @ images + C[:, :3, 3:]
elif num_channels == 1:
C = C[:, :3, :].mean(dim=1, keepdims=True)
images = images * C[:, :, :3].sum(dim=2, keepdims=True) + C[:, :, 3:]
else:
raise ValueError('Image must be RGB (3 channels) or L (1 channel)')
images = images.reshape([batch_size, num_channels, height, width])
# ----------------------
# Image-space filtering.
# ----------------------
if self.imgfilter > 0:
num_bands = self.Hz_fbank.shape[0]
assert len(self.imgfilter_bands) == num_bands
expected_power = misc.constant(np.array([10, 1, 1, 1]) / 13, device=device) # Expected power spectrum (1/f).
# Apply amplification for each band with probability (imgfilter * strength * band_strength).
g = torch.ones([batch_size, num_bands], device=device) # Global gain vector (identity).
for i, band_strength in enumerate(self.imgfilter_bands):
t_i = torch.exp2(torch.randn([batch_size], device=device) * self.imgfilter_std)
t_i = torch.where(torch.rand([batch_size], device=device) < self.imgfilter * self.p * band_strength, t_i, torch.ones_like(t_i))
if debug_percentile is not None:
t_i = torch.full_like(t_i, torch.exp2(torch.erfinv(debug_percentile * 2 - 1) * self.imgfilter_std)) if band_strength > 0 else torch.ones_like(t_i)
t = torch.ones([batch_size, num_bands], device=device) # Temporary gain vector.
t[:, i] = t_i # Replace i'th element.
t = t / (expected_power * t.square()).sum(dim=-1, keepdims=True).sqrt() # Normalize power.
g = g * t # Accumulate into global gain.
# Construct combined amplification filter.
Hz_prime = g @ self.Hz_fbank # [batch, tap]
Hz_prime = Hz_prime.unsqueeze(1).repeat([1, num_channels, 1]) # [batch, channels, tap]
Hz_prime = Hz_prime.reshape([batch_size * num_channels, 1, -1]) # [batch * channels, 1, tap]
# Apply filter.
p = self.Hz_fbank.shape[1] // 2
images = images.reshape([1, batch_size * num_channels, height, width])
images = torch.nn.functional.pad(input=images, pad=[p,p,p,p], mode='reflect')
images = conv2d_gradfix.conv2d(input=images, weight=Hz_prime.unsqueeze(2), groups=batch_size*num_channels)
images = conv2d_gradfix.conv2d(input=images, weight=Hz_prime.unsqueeze(3), groups=batch_size*num_channels)
images = images.reshape([batch_size, num_channels, height, width])
# ------------------------
# Image-space corruptions.
# ------------------------
# Apply additive RGB noise with probability (noise * strength).
if self.noise > 0:
sigma = torch.randn([batch_size, 1, 1, 1], device=device).abs() * self.noise_std
sigma = torch.where(torch.rand([batch_size, 1, 1, 1], device=device) < self.noise * self.p, sigma, torch.zeros_like(sigma))
if debug_percentile is not None:
sigma = torch.full_like(sigma, torch.erfinv(debug_percentile) * self.noise_std)
images = images + torch.randn([batch_size, num_channels, height, width], device=device) * sigma
# Apply cutout with probability (cutout * strength).
if self.cutout > 0:
size = torch.full([batch_size, 2, 1, 1, 1], self.cutout_size, device=device)
size = torch.where(torch.rand([batch_size, 1, 1, 1, 1], device=device) < self.cutout * self.p, size, torch.zeros_like(size))
center = torch.rand([batch_size, 2, 1, 1, 1], device=device)
if debug_percentile is not None:
size = torch.full_like(size, self.cutout_size)
center = torch.full_like(center, debug_percentile)
coord_x = torch.arange(width, device=device).reshape([1, 1, 1, -1])
coord_y = torch.arange(height, device=device).reshape([1, 1, -1, 1])
mask_x = (((coord_x + 0.5) / width - center[:, 0]).abs() >= size[:, 0] / 2)
mask_y = (((coord_y + 0.5) / height - center[:, 1]).abs() >= size[:, 1] / 2)
mask = torch.logical_or(mask_x, mask_y).to(torch.float32)
images = images * mask
return images
#----------------------------------------------------------------------------
|