Spaces:
Runtime error
Runtime error
File size: 14,923 Bytes
3424266 |
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 |
# --------------------------------------------------------
# Based on the timm code base
# https://github.com/huggingface/pytorch-image-models
# --------------------------------------------------------
""" Mixup and Cutmix
Papers:
mixup: Beyond Empirical Risk Minimization (https://arxiv.org/abs/1710.09412)
CutMix: Regularization Strategy to Train Strong Classifiers with Localizable Features (https://arxiv.org/abs/1905.04899)
Code Reference:
CutMix: https://github.com/clovaai/CutMix-PyTorch
Hacked together by / Copyright 2020 Ross Wightman
"""
import numpy as np
import torch
def one_hot(x, num_classes, on_value=1., off_value=0., device='cuda'):
x = x.long().view(-1, 1)
return torch.full((x.size()[0], num_classes), off_value, device=device).scatter_(1, x, on_value)
def mixup_target(target, num_classes, lam=1., smoothing=0.0, device='cuda'):
off_value = smoothing / num_classes
on_value = 1. - smoothing + off_value
y1 = one_hot(target, num_classes, on_value=on_value, off_value=off_value, device=device)
y2 = one_hot(target.flip(0), num_classes, on_value=on_value, off_value=off_value, device=device)
return y1 * lam + y2 * (1. - lam)
def rand_bbox(img_shape, lam, margin=0., count=None):
""" Standard CutMix bounding-box
Generates a random square bbox based on lambda value. This impl includes
support for enforcing a border margin as percent of bbox dimensions.
Args:
img_shape (tuple): Image shape as tuple
lam (float): Cutmix lambda value
margin (float): Percentage of bbox dimension to enforce as margin (reduce amount of box outside image)
count (int): Number of bbox to generate
"""
ratio = np.sqrt(1 - lam)
img_h, img_w = img_shape[-2:]
cut_h, cut_w = int(img_h * ratio), int(img_w * ratio)
margin_y, margin_x = int(margin * cut_h), int(margin * cut_w)
cy = np.random.randint(0 + margin_y, img_h - margin_y, size=count)
cx = np.random.randint(0 + margin_x, img_w - margin_x, size=count)
yl = np.clip(cy - cut_h // 2, 0, img_h)
yh = np.clip(cy + cut_h // 2, 0, img_h)
xl = np.clip(cx - cut_w // 2, 0, img_w)
xh = np.clip(cx + cut_w // 2, 0, img_w)
return yl, yh, xl, xh
def rand_bbox_minmax(img_shape, minmax, count=None):
""" Min-Max CutMix bounding-box
Inspired by Darknet cutmix impl, generates a random rectangular bbox
based on min/max percent values applied to each dimension of the input image.
Typical defaults for minmax are usually in the .2-.3 for min and .8-.9 range for max.
Args:
img_shape (tuple): Image shape as tuple
minmax (tuple or list): Min and max bbox ratios (as percent of image size)
count (int): Number of bbox to generate
"""
assert len(minmax) == 2
img_h, img_w = img_shape[-2:]
cut_h = np.random.randint(int(img_h * minmax[0]), int(img_h * minmax[1]), size=count)
cut_w = np.random.randint(int(img_w * minmax[0]), int(img_w * minmax[1]), size=count)
yl = np.random.randint(0, img_h - cut_h, size=count)
xl = np.random.randint(0, img_w - cut_w, size=count)
yu = yl + cut_h
xu = xl + cut_w
return yl, yu, xl, xu
def cutmix_bbox_and_lam(img_shape, lam, ratio_minmax=None, correct_lam=True, count=None):
""" Generate bbox and apply lambda correction.
"""
if ratio_minmax is not None:
yl, yu, xl, xu = rand_bbox_minmax(img_shape, ratio_minmax, count=count)
else:
yl, yu, xl, xu = rand_bbox(img_shape, lam, count=count)
if correct_lam or ratio_minmax is not None:
bbox_area = (yu - yl) * (xu - xl)
lam = 1. - bbox_area / float(img_shape[-2] * img_shape[-1])
return (yl, yu, xl, xu), lam
class Mixup:
""" Mixup/Cutmix that applies different params to each element or whole batch
Args:
mixup_alpha (float): mixup alpha value, mixup is active if > 0.
cutmix_alpha (float): cutmix alpha value, cutmix is active if > 0.
cutmix_minmax (List[float]): cutmix min/max image ratio, cutmix is active and uses this vs alpha if not None.
prob (float): probability of applying mixup or cutmix per batch or element
switch_prob (float): probability of switching to cutmix instead of mixup when both are active
mode (str): how to apply mixup/cutmix params (per 'batch', 'pair' (pair of elements), 'elem' (element)
correct_lam (bool): apply lambda correction when cutmix bbox clipped by image borders
label_smoothing (float): apply label smoothing to the mixed target tensor
num_classes (int): number of classes for target
"""
def __init__(self, mixup_alpha=1., cutmix_alpha=0., cutmix_minmax=None, prob=1.0, switch_prob=0.5,
mode='batch', correct_lam=True, label_smoothing=0.1, num_classes=1000):
self.mixup_alpha = mixup_alpha
self.cutmix_alpha = cutmix_alpha
self.cutmix_minmax = cutmix_minmax
if self.cutmix_minmax is not None:
assert len(self.cutmix_minmax) == 2
# force cutmix alpha == 1.0 when minmax active to keep logic simple & safe
self.cutmix_alpha = 1.0
self.mix_prob = prob
self.switch_prob = switch_prob
self.label_smoothing = label_smoothing
self.num_classes = num_classes
self.mode = mode
self.correct_lam = correct_lam # correct lambda based on clipped area for cutmix
self.mixup_enabled = True # set to false to disable mixing (intended tp be set by train loop)
def _params_per_elem(self, batch_size):
lam = np.ones(batch_size, dtype=np.float32)
use_cutmix = np.zeros(batch_size, dtype=np.bool)
if self.mixup_enabled:
if self.mixup_alpha > 0. and self.cutmix_alpha > 0.:
use_cutmix = np.random.rand(batch_size) < self.switch_prob
lam_mix = np.where(
use_cutmix,
np.random.beta(self.cutmix_alpha, self.cutmix_alpha, size=batch_size),
np.random.beta(self.mixup_alpha, self.mixup_alpha, size=batch_size))
elif self.mixup_alpha > 0.:
lam_mix = np.random.beta(self.mixup_alpha, self.mixup_alpha, size=batch_size)
elif self.cutmix_alpha > 0.:
use_cutmix = np.ones(batch_size, dtype=np.bool)
lam_mix = np.random.beta(self.cutmix_alpha, self.cutmix_alpha, size=batch_size)
else:
assert False, "One of mixup_alpha > 0., cutmix_alpha > 0., cutmix_minmax not None should be true."
lam = np.where(np.random.rand(batch_size) < self.mix_prob, lam_mix.astype(np.float32), lam)
return lam, use_cutmix
def _params_per_batch(self):
lam = 1.
use_cutmix = False
if self.mixup_enabled and np.random.rand() < self.mix_prob:
if self.mixup_alpha > 0. and self.cutmix_alpha > 0.:
use_cutmix = np.random.rand() < self.switch_prob
lam_mix = np.random.beta(self.cutmix_alpha, self.cutmix_alpha) if use_cutmix else \
np.random.beta(self.mixup_alpha, self.mixup_alpha)
elif self.mixup_alpha > 0.:
lam_mix = np.random.beta(self.mixup_alpha, self.mixup_alpha)
elif self.cutmix_alpha > 0.:
use_cutmix = True
lam_mix = np.random.beta(self.cutmix_alpha, self.cutmix_alpha)
else:
assert False, "One of mixup_alpha > 0., cutmix_alpha > 0., cutmix_minmax not None should be true."
lam = float(lam_mix)
return lam, use_cutmix
def _mix_elem(self, x):
batch_size = len(x)
lam_batch, use_cutmix = self._params_per_elem(batch_size)
x_orig = x.clone() # need to keep an unmodified original for mixing source
for i in range(batch_size):
j = batch_size - i - 1
lam = lam_batch[i]
if lam != 1.:
if use_cutmix[i]:
(yl, yh, xl, xh), lam = cutmix_bbox_and_lam(
x[i].shape, lam, ratio_minmax=self.cutmix_minmax, correct_lam=self.correct_lam)
x[i][:, yl:yh, xl:xh] = x_orig[j][:, yl:yh, xl:xh]
lam_batch[i] = lam
else:
x[i] = x[i] * lam + x_orig[j] * (1 - lam)
return torch.tensor(lam_batch, device=x.device, dtype=x.dtype).unsqueeze(1)
def _mix_pair(self, x):
batch_size = len(x)
lam_batch, use_cutmix = self._params_per_elem(batch_size // 2)
x_orig = x.clone() # need to keep an unmodified original for mixing source
for i in range(batch_size // 2):
j = batch_size - i - 1
lam = lam_batch[i]
if lam != 1.:
if use_cutmix[i]:
(yl, yh, xl, xh), lam = cutmix_bbox_and_lam(
x[i].shape, lam, ratio_minmax=self.cutmix_minmax, correct_lam=self.correct_lam)
x[i][:, yl:yh, xl:xh] = x_orig[j][:, yl:yh, xl:xh]
x[j][:, yl:yh, xl:xh] = x_orig[i][:, yl:yh, xl:xh]
lam_batch[i] = lam
else:
x[i] = x[i] * lam + x_orig[j] * (1 - lam)
x[j] = x[j] * lam + x_orig[i] * (1 - lam)
lam_batch = np.concatenate((lam_batch, lam_batch[::-1]))
return torch.tensor(lam_batch, device=x.device, dtype=x.dtype).unsqueeze(1)
def _mix_batch(self, x):
lam, use_cutmix = self._params_per_batch()
if lam == 1.:
return 1.
if use_cutmix:
(yl, yh, xl, xh), lam = cutmix_bbox_and_lam(
x.shape, lam, ratio_minmax=self.cutmix_minmax, correct_lam=self.correct_lam)
x[:, :, yl:yh, xl:xh] = x.flip(0)[:, :, yl:yh, xl:xh]
else:
x_flipped = x.flip(0).mul_(1. - lam)
x.mul_(lam).add_(x_flipped)
return lam
def __call__(self, x, target):
assert len(x) % 2 == 0, 'Batch size should be even when using this'
if self.mode == 'elem':
lam = self._mix_elem(x)
elif self.mode == 'pair':
lam = self._mix_pair(x)
else:
lam = self._mix_batch(x)
target = mixup_target(target, self.num_classes, lam, self.label_smoothing, x.device)
return x, target
class FastCollateMixup(Mixup):
""" Fast Collate w/ Mixup/Cutmix that applies different params to each element or whole batch
A Mixup impl that's performed while collating the batches.
"""
def _mix_elem_collate(self, output, batch, half=False):
batch_size = len(batch)
num_elem = batch_size // 2 if half else batch_size
assert len(output) == num_elem
lam_batch, use_cutmix = self._params_per_elem(num_elem)
for i in range(num_elem):
j = batch_size - i - 1
lam = lam_batch[i]
mixed = batch[i][0]
if lam != 1.:
if use_cutmix[i]:
if not half:
mixed = mixed.copy()
(yl, yh, xl, xh), lam = cutmix_bbox_and_lam(
output.shape, lam, ratio_minmax=self.cutmix_minmax, correct_lam=self.correct_lam)
mixed[:, yl:yh, xl:xh] = batch[j][0][:, yl:yh, xl:xh]
lam_batch[i] = lam
else:
mixed = mixed.astype(np.float32) * lam + batch[j][0].astype(np.float32) * (1 - lam)
np.rint(mixed, out=mixed)
output[i] += torch.from_numpy(mixed.astype(np.uint8))
if half:
lam_batch = np.concatenate((lam_batch, np.ones(num_elem)))
return torch.tensor(lam_batch).unsqueeze(1)
def _mix_pair_collate(self, output, batch):
batch_size = len(batch)
lam_batch, use_cutmix = self._params_per_elem(batch_size // 2)
for i in range(batch_size // 2):
j = batch_size - i - 1
lam = lam_batch[i]
mixed_i = batch[i][0]
mixed_j = batch[j][0]
assert 0 <= lam <= 1.0
if lam < 1.:
if use_cutmix[i]:
(yl, yh, xl, xh), lam = cutmix_bbox_and_lam(
output.shape, lam, ratio_minmax=self.cutmix_minmax, correct_lam=self.correct_lam)
patch_i = mixed_i[:, yl:yh, xl:xh].copy()
mixed_i[:, yl:yh, xl:xh] = mixed_j[:, yl:yh, xl:xh]
mixed_j[:, yl:yh, xl:xh] = patch_i
lam_batch[i] = lam
else:
mixed_temp = mixed_i.astype(np.float32) * lam + mixed_j.astype(np.float32) * (1 - lam)
mixed_j = mixed_j.astype(np.float32) * lam + mixed_i.astype(np.float32) * (1 - lam)
mixed_i = mixed_temp
np.rint(mixed_j, out=mixed_j)
np.rint(mixed_i, out=mixed_i)
output[i] += torch.from_numpy(mixed_i.astype(np.uint8))
output[j] += torch.from_numpy(mixed_j.astype(np.uint8))
lam_batch = np.concatenate((lam_batch, lam_batch[::-1]))
return torch.tensor(lam_batch).unsqueeze(1)
def _mix_batch_collate(self, output, batch):
batch_size = len(batch)
lam, use_cutmix = self._params_per_batch()
if use_cutmix:
(yl, yh, xl, xh), lam = cutmix_bbox_and_lam(
output.shape, lam, ratio_minmax=self.cutmix_minmax, correct_lam=self.correct_lam)
for i in range(batch_size):
j = batch_size - i - 1
mixed = batch[i][0]
if lam != 1.:
if use_cutmix:
mixed = mixed.copy() # don't want to modify the original while iterating
mixed[:, yl:yh, xl:xh] = batch[j][0][:, yl:yh, xl:xh]
else:
mixed = mixed.astype(np.float32) * lam + batch[j][0].astype(np.float32) * (1 - lam)
np.rint(mixed, out=mixed)
output[i] += torch.from_numpy(mixed.astype(np.uint8))
return lam
def __call__(self, batch, _=None):
batch_size = len(batch)
assert batch_size % 2 == 0, 'Batch size should be even when using this'
half = 'half' in self.mode
if half:
batch_size //= 2
output = torch.zeros((batch_size, *batch[0][0].shape), dtype=torch.uint8)
if self.mode == 'elem' or self.mode == 'half':
lam = self._mix_elem_collate(output, batch, half=half)
elif self.mode == 'pair':
lam = self._mix_pair_collate(output, batch)
else:
lam = self._mix_batch_collate(output, batch)
target = torch.tensor([b[1] for b in batch], dtype=torch.int64)
target = mixup_target(target, self.num_classes, lam, self.label_smoothing, device='cpu')
target = target[:batch_size]
return output, target
|