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1
+
2
+ """
3
+ wild mixture of
4
+ https://github.com/lucidrains/denoising-diffusion-pytorch/blob/7706bdfc6f527f58d33f84b7b522e61e6e3164b3/denoising_diffusion_pytorch/denoising_diffusion_pytorch.py
5
+ https://github.com/openai/improved-diffusion/blob/e94489283bb876ac1477d5dd7709bbbd2d9902ce/improved_diffusion/gaussian_diffusion.py
6
+ https://github.com/CompVis/taming-transformers
7
+ -- merci
8
+ """
9
+
10
+ import torch
11
+ import torch.nn as nn
12
+ import numpy as np
13
+ import pytorch_lightning as pl
14
+ from torch.optim.lr_scheduler import LambdaLR
15
+ from einops import rearrange, repeat
16
+ from contextlib import contextmanager, nullcontext
17
+ from functools import partial
18
+ import itertools
19
+ from tqdm import tqdm
20
+ from torchvision.utils import make_grid
21
+ from pytorch_lightning.utilities.rank_zero import rank_zero_only
22
+ from omegaconf import ListConfig
23
+
24
+ from ldm.util import log_txt_as_img, exists, default, ismap, isimage, mean_flat, count_params, instantiate_from_config
25
+ from ldm.modules.ema import LitEma
26
+ from ldm.modules.distributions.distributions import normal_kl, DiagonalGaussianDistribution
27
+ from ldm.models.autoencoder import IdentityFirstStage, AutoencoderKL
28
+ from ldm.modules.diffusionmodules.util import make_beta_schedule, extract_into_tensor, noise_like
29
+ from ldm.models.diffusion.ddim import DDIMSampler
30
+
31
+
32
+ __conditioning_keys__ = {'concat': 'c_concat',
33
+ 'crossattn': 'c_crossattn',
34
+ 'adm': 'y'}
35
+
36
+
37
+ def disabled_train(self, mode=True):
38
+ """Overwrite model.train with this function to make sure train/eval mode
39
+ does not change anymore."""
40
+ return self
41
+
42
+
43
+ def uniform_on_device(r1, r2, shape, device):
44
+ return (r1 - r2) * torch.rand(*shape, device=device) + r2
45
+
46
+
47
+ class DDPM(pl.LightningModule):
48
+ # classic DDPM with Gaussian diffusion, in image space
49
+ def __init__(self,
50
+ unet_config,
51
+ timesteps=1000,
52
+ beta_schedule="linear",
53
+ loss_type="l2",
54
+ ckpt_path=None,
55
+ ignore_keys=[],
56
+ load_only_unet=False,
57
+ monitor="val/loss",
58
+ use_ema=True,
59
+ first_stage_key="image",
60
+ image_size=256,
61
+ channels=3,
62
+ log_every_t=100,
63
+ clip_denoised=True,
64
+ linear_start=1e-4,
65
+ linear_end=2e-2,
66
+ cosine_s=8e-3,
67
+ given_betas=None,
68
+ original_elbo_weight=0.,
69
+ v_posterior=0., # weight for choosing posterior variance as sigma = (1-v) * beta_tilde + v * beta
70
+ l_simple_weight=1.,
71
+ conditioning_key=None,
72
+ parameterization="eps", # all assuming fixed variance schedules
73
+ scheduler_config=None,
74
+ use_positional_encodings=False,
75
+ learn_logvar=False,
76
+ logvar_init=0.,
77
+ make_it_fit=False,
78
+ ucg_training=None,
79
+ reset_ema=False,
80
+ reset_num_ema_updates=False,
81
+ ):
82
+ super().__init__()
83
+ assert parameterization in ["eps", "x0", "v"], 'currently only supporting "eps" and "x0" and "v"'
84
+ self.parameterization = parameterization
85
+ print(f"{self.__class__.__name__}: Running in {self.parameterization}-prediction mode")
86
+ self.cond_stage_model = None
87
+ self.clip_denoised = clip_denoised
88
+ self.log_every_t = log_every_t
89
+ self.first_stage_key = first_stage_key
90
+ self.image_size = image_size # try conv?
91
+ self.channels = channels
92
+ self.use_positional_encodings = use_positional_encodings
93
+ self.model = DiffusionWrapper(unet_config, conditioning_key)
94
+ count_params(self.model, verbose=True)
95
+ self.use_ema = use_ema
96
+ if self.use_ema:
97
+ self.model_ema = LitEma(self.model)
98
+ print(f"Keeping EMAs of {len(list(self.model_ema.buffers()))}.")
99
+
100
+ self.use_scheduler = scheduler_config is not None
101
+ if self.use_scheduler:
102
+ self.scheduler_config = scheduler_config
103
+
104
+ self.v_posterior = v_posterior
105
+ self.original_elbo_weight = original_elbo_weight
106
+ self.l_simple_weight = l_simple_weight
107
+
108
+ if monitor is not None:
109
+ self.monitor = monitor
110
+ self.make_it_fit = make_it_fit
111
+ if reset_ema: assert exists(ckpt_path)
112
+ if ckpt_path is not None:
113
+ self.init_from_ckpt(ckpt_path, ignore_keys=ignore_keys, only_model=load_only_unet)
114
+ if reset_ema:
115
+ assert self.use_ema
116
+ print(f"Resetting ema to pure model weights. This is useful when restoring from an ema-only checkpoint.")
117
+ self.model_ema = LitEma(self.model)
118
+ if reset_num_ema_updates:
119
+ print(" +++++++++++ WARNING: RESETTING NUM_EMA UPDATES TO ZERO +++++++++++ ")
120
+ assert self.use_ema
121
+ self.model_ema.reset_num_updates()
122
+
123
+ self.register_schedule(given_betas=given_betas, beta_schedule=beta_schedule, timesteps=timesteps,
124
+ linear_start=linear_start, linear_end=linear_end, cosine_s=cosine_s)
125
+
126
+ self.loss_type = loss_type
127
+
128
+ self.learn_logvar = learn_logvar
129
+ self.logvar = torch.full(fill_value=logvar_init, size=(self.num_timesteps,))
130
+ if self.learn_logvar:
131
+ self.logvar = nn.Parameter(self.logvar, requires_grad=True)
132
+
133
+ self.ucg_training = ucg_training or dict()
134
+ if self.ucg_training:
135
+ self.ucg_prng = np.random.RandomState()
136
+
137
+ def register_schedule(self, given_betas=None, beta_schedule="linear", timesteps=1000,
138
+ linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3):
139
+ if exists(given_betas):
140
+ betas = given_betas
141
+ else:
142
+ betas = make_beta_schedule(beta_schedule, timesteps, linear_start=linear_start, linear_end=linear_end,
143
+ cosine_s=cosine_s)
144
+ alphas = 1. - betas
145
+ alphas_cumprod = np.cumprod(alphas, axis=0)
146
+ alphas_cumprod_prev = np.append(1., alphas_cumprod[:-1])
147
+
148
+ timesteps, = betas.shape
149
+ self.num_timesteps = int(timesteps)
150
+ self.linear_start = linear_start
151
+ self.linear_end = linear_end
152
+ assert alphas_cumprod.shape[0] == self.num_timesteps, 'alphas have to be defined for each timestep'
153
+
154
+ to_torch = partial(torch.tensor, dtype=torch.float32)
155
+
156
+ self.register_buffer('betas', to_torch(betas))
157
+ self.register_buffer('alphas_cumprod', to_torch(alphas_cumprod))
158
+ self.register_buffer('alphas_cumprod_prev', to_torch(alphas_cumprod_prev))
159
+
160
+ # calculations for diffusion q(x_t | x_{t-1}) and others
161
+ self.register_buffer('sqrt_alphas_cumprod', to_torch(np.sqrt(alphas_cumprod)))
162
+ self.register_buffer('sqrt_one_minus_alphas_cumprod', to_torch(np.sqrt(1. - alphas_cumprod)))
163
+ self.register_buffer('log_one_minus_alphas_cumprod', to_torch(np.log(1. - alphas_cumprod)))
164
+ self.register_buffer('sqrt_recip_alphas_cumprod', to_torch(np.sqrt(1. / alphas_cumprod)))
165
+ self.register_buffer('sqrt_recipm1_alphas_cumprod', to_torch(np.sqrt(1. / alphas_cumprod - 1)))
166
+
167
+ # calculations for posterior q(x_{t-1} | x_t, x_0)
168
+ posterior_variance = (1 - self.v_posterior) * betas * (1. - alphas_cumprod_prev) / (
169
+ 1. - alphas_cumprod) + self.v_posterior * betas
170
+ # above: equal to 1. / (1. / (1. - alpha_cumprod_tm1) + alpha_t / beta_t)
171
+ self.register_buffer('posterior_variance', to_torch(posterior_variance))
172
+ # below: log calculation clipped because the posterior variance is 0 at the beginning of the diffusion chain
173
+ self.register_buffer('posterior_log_variance_clipped', to_torch(np.log(np.maximum(posterior_variance, 1e-20))))
174
+ self.register_buffer('posterior_mean_coef1', to_torch(
175
+ betas * np.sqrt(alphas_cumprod_prev) / (1. - alphas_cumprod)))
176
+ self.register_buffer('posterior_mean_coef2', to_torch(
177
+ (1. - alphas_cumprod_prev) * np.sqrt(alphas) / (1. - alphas_cumprod)))
178
+
179
+ if self.parameterization == "eps":
180
+ lvlb_weights = self.betas ** 2 / (
181
+ 2 * self.posterior_variance * to_torch(alphas) * (1 - self.alphas_cumprod))
182
+ elif self.parameterization == "x0":
183
+ lvlb_weights = 0.5 * np.sqrt(torch.Tensor(alphas_cumprod)) / (2. * 1 - torch.Tensor(alphas_cumprod))
184
+ elif self.parameterization == "v":
185
+ lvlb_weights = torch.ones_like(self.betas ** 2 / (
186
+ 2 * self.posterior_variance * to_torch(alphas) * (1 - self.alphas_cumprod)))
187
+ else:
188
+ raise NotImplementedError("mu not supported")
189
+ lvlb_weights[0] = lvlb_weights[1]
190
+ self.register_buffer('lvlb_weights', lvlb_weights, persistent=False)
191
+ assert not torch.isnan(self.lvlb_weights).all()
192
+
193
+ @contextmanager
194
+ def ema_scope(self, context=None):
195
+ if self.use_ema:
196
+ self.model_ema.store(self.model.parameters())
197
+ self.model_ema.copy_to(self.model)
198
+ if context is not None:
199
+ print(f"{context}: Switched to EMA weights")
200
+ try:
201
+ yield None
202
+ finally:
203
+ if self.use_ema:
204
+ self.model_ema.restore(self.model.parameters())
205
+ if context is not None:
206
+ print(f"{context}: Restored training weights")
207
+
208
+ @torch.no_grad()
209
+ def init_from_ckpt(self, path, ignore_keys=list(), only_model=False):
210
+ sd = torch.load(path, map_location="cpu")
211
+ if "state_dict" in list(sd.keys()):
212
+ sd = sd["state_dict"]
213
+ keys = list(sd.keys())
214
+ for k in keys:
215
+ for ik in ignore_keys:
216
+ if k.startswith(ik):
217
+ print("Deleting key {} from state_dict.".format(k))
218
+ del sd[k]
219
+ if self.make_it_fit:
220
+ n_params = len([name for name, _ in
221
+ itertools.chain(self.named_parameters(),
222
+ self.named_buffers())])
223
+ for name, param in tqdm(
224
+ itertools.chain(self.named_parameters(),
225
+ self.named_buffers()),
226
+ desc="Fitting old weights to new weights",
227
+ total=n_params
228
+ ):
229
+ if not name in sd:
230
+ continue
231
+ old_shape = sd[name].shape
232
+ new_shape = param.shape
233
+ assert len(old_shape) == len(new_shape)
234
+ if len(new_shape) > 2:
235
+ # we only modify first two axes
236
+ assert new_shape[2:] == old_shape[2:]
237
+ # assumes first axis corresponds to output dim
238
+ if not new_shape == old_shape:
239
+ new_param = param.clone()
240
+ old_param = sd[name]
241
+ if len(new_shape) == 1:
242
+ for i in range(new_param.shape[0]):
243
+ new_param[i] = old_param[i % old_shape[0]]
244
+ elif len(new_shape) >= 2:
245
+ for i in range(new_param.shape[0]):
246
+ for j in range(new_param.shape[1]):
247
+ new_param[i, j] = old_param[i % old_shape[0], j % old_shape[1]]
248
+
249
+ n_used_old = torch.ones(old_shape[1])
250
+ for j in range(new_param.shape[1]):
251
+ n_used_old[j % old_shape[1]] += 1
252
+ n_used_new = torch.zeros(new_shape[1])
253
+ for j in range(new_param.shape[1]):
254
+ n_used_new[j] = n_used_old[j % old_shape[1]]
255
+
256
+ n_used_new = n_used_new[None, :]
257
+ while len(n_used_new.shape) < len(new_shape):
258
+ n_used_new = n_used_new.unsqueeze(-1)
259
+ new_param /= n_used_new
260
+
261
+ sd[name] = new_param
262
+
263
+ missing, unexpected = self.load_state_dict(sd, strict=False) if not only_model else self.model.load_state_dict(
264
+ sd, strict=False)
265
+ print(f"Restored from {path} with {len(missing)} missing and {len(unexpected)} unexpected keys")
266
+ if len(missing) > 0:
267
+ print(f"Missing Keys:\n {missing}")
268
+ if len(unexpected) > 0:
269
+ print(f"\nUnexpected Keys:\n {unexpected}")
270
+
271
+ def q_mean_variance(self, x_start, t):
272
+ """
273
+ Get the distribution q(x_t | x_0).
274
+ :param x_start: the [N x C x ...] tensor of noiseless inputs.
275
+ :param t: the number of diffusion steps (minus 1). Here, 0 means one step.
276
+ :return: A tuple (mean, variance, log_variance), all of x_start's shape.
277
+ """
278
+ mean = (extract_into_tensor(self.sqrt_alphas_cumprod, t, x_start.shape) * x_start)
279
+ variance = extract_into_tensor(1.0 - self.alphas_cumprod, t, x_start.shape)
280
+ log_variance = extract_into_tensor(self.log_one_minus_alphas_cumprod, t, x_start.shape)
281
+ return mean, variance, log_variance
282
+
283
+ def predict_start_from_noise(self, x_t, t, noise):
284
+ return (
285
+ extract_into_tensor(self.sqrt_recip_alphas_cumprod, t, x_t.shape) * x_t -
286
+ extract_into_tensor(self.sqrt_recipm1_alphas_cumprod, t, x_t.shape) * noise
287
+ )
288
+
289
+ def predict_start_from_z_and_v(self, x_t, t, v):
290
+ # self.register_buffer('sqrt_alphas_cumprod', to_torch(np.sqrt(alphas_cumprod)))
291
+ # self.register_buffer('sqrt_one_minus_alphas_cumprod', to_torch(np.sqrt(1. - alphas_cumprod)))
292
+ return (
293
+ extract_into_tensor(self.sqrt_alphas_cumprod, t, x_t.shape) * x_t -
294
+ extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x_t.shape) * v
295
+ )
296
+
297
+ def predict_eps_from_z_and_v(self, x_t, t, v):
298
+ return (
299
+ extract_into_tensor(self.sqrt_alphas_cumprod, t, x_t.shape) * v +
300
+ extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x_t.shape) * x_t
301
+ )
302
+
303
+ def q_posterior(self, x_start, x_t, t):
304
+ posterior_mean = (
305
+ extract_into_tensor(self.posterior_mean_coef1, t, x_t.shape) * x_start +
306
+ extract_into_tensor(self.posterior_mean_coef2, t, x_t.shape) * x_t
307
+ )
308
+ posterior_variance = extract_into_tensor(self.posterior_variance, t, x_t.shape)
309
+ posterior_log_variance_clipped = extract_into_tensor(self.posterior_log_variance_clipped, t, x_t.shape)
310
+ return posterior_mean, posterior_variance, posterior_log_variance_clipped
311
+
312
+ def p_mean_variance(self, x, t, clip_denoised: bool):
313
+ model_out = self.model(x, t)
314
+ if self.parameterization == "eps":
315
+ x_recon = self.predict_start_from_noise(x, t=t, noise=model_out)
316
+ elif self.parameterization == "x0":
317
+ x_recon = model_out
318
+ if clip_denoised:
319
+ x_recon.clamp_(-1., 1.)
320
+
321
+ model_mean, posterior_variance, posterior_log_variance = self.q_posterior(x_start=x_recon, x_t=x, t=t)
322
+ return model_mean, posterior_variance, posterior_log_variance
323
+
324
+ @torch.no_grad()
325
+ def p_sample(self, x, t, clip_denoised=True, repeat_noise=False):
326
+ b, *_, device = *x.shape, x.device
327
+ model_mean, _, model_log_variance = self.p_mean_variance(x=x, t=t, clip_denoised=clip_denoised)
328
+ noise = noise_like(x.shape, device, repeat_noise)
329
+ # no noise when t == 0
330
+ nonzero_mask = (1 - (t == 0).float()).reshape(b, *((1,) * (len(x.shape) - 1)))
331
+ return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise
332
+
333
+ @torch.no_grad()
334
+ def p_sample_loop(self, shape, return_intermediates=False):
335
+ device = self.betas.device
336
+ b = shape[0]
337
+ img = torch.randn(shape, device=device)
338
+ intermediates = [img]
339
+ for i in tqdm(reversed(range(0, self.num_timesteps)), desc='Sampling t', total=self.num_timesteps):
340
+ img = self.p_sample(img, torch.full((b,), i, device=device, dtype=torch.long),
341
+ clip_denoised=self.clip_denoised)
342
+ if i % self.log_every_t == 0 or i == self.num_timesteps - 1:
343
+ intermediates.append(img)
344
+ if return_intermediates:
345
+ return img, intermediates
346
+ return img
347
+
348
+ @torch.no_grad()
349
+ def sample(self, batch_size=16, return_intermediates=False):
350
+ image_size = self.image_size
351
+ channels = self.channels
352
+ return self.p_sample_loop((batch_size, channels, image_size, image_size),
353
+ return_intermediates=return_intermediates)
354
+
355
+ def q_sample(self, x_start, t, noise=None):
356
+ noise = default(noise, lambda: torch.randn_like(x_start))
357
+ return (extract_into_tensor(self.sqrt_alphas_cumprod, t, x_start.shape) * x_start +
358
+ extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x_start.shape) * noise)
359
+
360
+ def get_v(self, x, noise, t):
361
+ return (
362
+ extract_into_tensor(self.sqrt_alphas_cumprod, t, x.shape) * noise -
363
+ extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x.shape) * x
364
+ )
365
+
366
+ def get_loss(self, pred, target, mean=True):
367
+ if self.loss_type == 'l1':
368
+ loss = (target - pred).abs()
369
+ if mean:
370
+ loss = loss.mean()
371
+ elif self.loss_type == 'l2':
372
+ if mean:
373
+ loss = torch.nn.functional.mse_loss(target, pred)
374
+ else:
375
+ loss = torch.nn.functional.mse_loss(target, pred, reduction='none')
376
+ else:
377
+ raise NotImplementedError("unknown loss type '{loss_type}'")
378
+
379
+ return loss
380
+
381
+ def p_losses(self, x_start, t, noise=None):
382
+ noise = default(noise, lambda: torch.randn_like(x_start))
383
+ x_noisy = self.q_sample(x_start=x_start, t=t, noise=noise)
384
+ model_out = self.model(x_noisy, t)
385
+
386
+ loss_dict = {}
387
+ if self.parameterization == "eps":
388
+ target = noise
389
+ elif self.parameterization == "x0":
390
+ target = x_start
391
+ elif self.parameterization == "v":
392
+ target = self.get_v(x_start, noise, t)
393
+ else:
394
+ raise NotImplementedError(f"Parameterization {self.parameterization} not yet supported")
395
+
396
+ loss = self.get_loss(model_out, target, mean=False).mean(dim=[1, 2, 3])
397
+
398
+ log_prefix = 'train' if self.training else 'val'
399
+
400
+ loss_dict.update({f'{log_prefix}/loss_simple': loss.mean()})
401
+ loss_simple = loss.mean() * self.l_simple_weight
402
+
403
+ loss_vlb = (self.lvlb_weights[t] * loss).mean()
404
+ loss_dict.update({f'{log_prefix}/loss_vlb': loss_vlb})
405
+
406
+ loss = loss_simple + self.original_elbo_weight * loss_vlb
407
+
408
+ loss_dict.update({f'{log_prefix}/loss': loss})
409
+
410
+ return loss, loss_dict
411
+
412
+ def forward(self, x, *args, **kwargs):
413
+ # b, c, h, w, device, img_size, = *x.shape, x.device, self.image_size
414
+ # assert h == img_size and w == img_size, f'height and width of image must be {img_size}'
415
+ t = torch.randint(0, self.num_timesteps, (x.shape[0],), device=self.device).long()
416
+ return self.p_losses(x, t, *args, **kwargs)
417
+
418
+ def get_input(self, batch, k):
419
+ x = batch[k]
420
+ if len(x.shape) == 3:
421
+ x = x[..., None]
422
+ x = rearrange(x, 'b h w c -> b c h w')
423
+ x = x.to(memory_format=torch.contiguous_format).float()
424
+ return x
425
+
426
+ def shared_step(self, batch):
427
+ x = self.get_input(batch, self.first_stage_key)
428
+ loss, loss_dict = self(x)
429
+ return loss, loss_dict
430
+
431
+ def training_step(self, batch, batch_idx):
432
+ for k in self.ucg_training:
433
+ p = self.ucg_training[k]["p"]
434
+ val = self.ucg_training[k]["val"]
435
+ if val is None:
436
+ val = ""
437
+ for i in range(len(batch[k])):
438
+ if self.ucg_prng.choice(2, p=[1 - p, p]):
439
+ batch[k][i] = val
440
+
441
+ loss, loss_dict = self.shared_step(batch)
442
+
443
+ self.log_dict(loss_dict, prog_bar=True,
444
+ logger=True, on_step=True, on_epoch=True)
445
+
446
+ self.log("global_step", self.global_step,
447
+ prog_bar=True, logger=True, on_step=True, on_epoch=False)
448
+
449
+ if self.use_scheduler:
450
+ lr = self.optimizers().param_groups[0]['lr']
451
+ self.log('lr_abs', lr, prog_bar=True, logger=True, on_step=True, on_epoch=False)
452
+
453
+ return loss
454
+
455
+ @torch.no_grad()
456
+ def validation_step(self, batch, batch_idx):
457
+ _, loss_dict_no_ema = self.shared_step(batch)
458
+ with self.ema_scope():
459
+ _, loss_dict_ema = self.shared_step(batch)
460
+ loss_dict_ema = {key + '_ema': loss_dict_ema[key] for key in loss_dict_ema}
461
+ self.log_dict(loss_dict_no_ema, prog_bar=False, logger=True, on_step=False, on_epoch=True)
462
+ self.log_dict(loss_dict_ema, prog_bar=False, logger=True, on_step=False, on_epoch=True)
463
+
464
+ def on_train_batch_end(self, *args, **kwargs):
465
+ if self.use_ema:
466
+ self.model_ema(self.model)
467
+
468
+ def _get_rows_from_list(self, samples):
469
+ n_imgs_per_row = len(samples)
470
+ denoise_grid = rearrange(samples, 'n b c h w -> b n c h w')
471
+ denoise_grid = rearrange(denoise_grid, 'b n c h w -> (b n) c h w')
472
+ denoise_grid = make_grid(denoise_grid, nrow=n_imgs_per_row)
473
+ return denoise_grid
474
+
475
+ @torch.no_grad()
476
+ def log_images(self, batch, N=8, n_row=2, sample=True, return_keys=None, **kwargs):
477
+ log = dict()
478
+ x = self.get_input(batch, self.first_stage_key)
479
+ N = min(x.shape[0], N)
480
+ n_row = min(x.shape[0], n_row)
481
+ x = x.to(self.device)[:N]
482
+ log["inputs"] = x
483
+
484
+ # get diffusion row
485
+ diffusion_row = list()
486
+ x_start = x[:n_row]
487
+
488
+ for t in range(self.num_timesteps):
489
+ if t % self.log_every_t == 0 or t == self.num_timesteps - 1:
490
+ t = repeat(torch.tensor([t]), '1 -> b', b=n_row)
491
+ t = t.to(self.device).long()
492
+ noise = torch.randn_like(x_start)
493
+ x_noisy = self.q_sample(x_start=x_start, t=t, noise=noise)
494
+ diffusion_row.append(x_noisy)
495
+
496
+ log["diffusion_row"] = self._get_rows_from_list(diffusion_row)
497
+
498
+ if sample:
499
+ # get denoise row
500
+ with self.ema_scope("Plotting"):
501
+ samples, denoise_row = self.sample(batch_size=N, return_intermediates=True)
502
+
503
+ log["samples"] = samples
504
+ log["denoise_row"] = self._get_rows_from_list(denoise_row)
505
+
506
+ if return_keys:
507
+ if np.intersect1d(list(log.keys()), return_keys).shape[0] == 0:
508
+ return log
509
+ else:
510
+ return {key: log[key] for key in return_keys}
511
+ return log
512
+
513
+ def configure_optimizers(self):
514
+ lr = self.learning_rate
515
+ params = list(self.model.parameters())
516
+ if self.learn_logvar:
517
+ params = params + [self.logvar]
518
+ opt = torch.optim.AdamW(params, lr=lr)
519
+ return opt
520
+
521
+
522
+ class LatentDiffusion(DDPM):
523
+ """main class"""
524
+
525
+ def __init__(self,
526
+ first_stage_config,
527
+ cond_stage_config,
528
+ num_timesteps_cond=None,
529
+ cond_stage_key="image",
530
+ cond_stage_trainable=False,
531
+ concat_mode=True,
532
+ cond_stage_forward=None,
533
+ conditioning_key=None,
534
+ scale_factor=1.0,
535
+ scale_by_std=False,
536
+ force_null_conditioning=False,
537
+ *args, **kwargs):
538
+ self.force_null_conditioning = force_null_conditioning
539
+ self.num_timesteps_cond = default(num_timesteps_cond, 1)
540
+ self.scale_by_std = scale_by_std
541
+ assert self.num_timesteps_cond <= kwargs['timesteps']
542
+ # for backwards compatibility after implementation of DiffusionWrapper
543
+ if conditioning_key is None:
544
+ conditioning_key = 'concat' if concat_mode else 'crossattn'
545
+ if cond_stage_config == '__is_unconditional__' and not self.force_null_conditioning:
546
+ conditioning_key = None
547
+ ckpt_path = kwargs.pop("ckpt_path", None)
548
+ reset_ema = kwargs.pop("reset_ema", False)
549
+ reset_num_ema_updates = kwargs.pop("reset_num_ema_updates", False)
550
+ ignore_keys = kwargs.pop("ignore_keys", [])
551
+ super().__init__(conditioning_key=conditioning_key, *args, **kwargs)
552
+ self.concat_mode = concat_mode
553
+ self.cond_stage_trainable = cond_stage_trainable
554
+ self.cond_stage_key = cond_stage_key
555
+ try:
556
+ self.num_downs = len(first_stage_config.params.ddconfig.ch_mult) - 1
557
+ except:
558
+ self.num_downs = 0
559
+ if not scale_by_std:
560
+ self.scale_factor = scale_factor
561
+ else:
562
+ self.register_buffer('scale_factor', torch.tensor(scale_factor))
563
+ self.instantiate_first_stage(first_stage_config)
564
+ self.instantiate_cond_stage(cond_stage_config)
565
+ self.cond_stage_forward = cond_stage_forward
566
+ self.clip_denoised = False
567
+ self.bbox_tokenizer = None
568
+
569
+ self.restarted_from_ckpt = False
570
+ if ckpt_path is not None:
571
+ self.init_from_ckpt(ckpt_path, ignore_keys)
572
+ self.restarted_from_ckpt = True
573
+ if reset_ema:
574
+ assert self.use_ema
575
+ print(
576
+ f"Resetting ema to pure model weights. This is useful when restoring from an ema-only checkpoint.")
577
+ self.model_ema = LitEma(self.model)
578
+ if reset_num_ema_updates:
579
+ print(" +++++++++++ WARNING: RESETTING NUM_EMA UPDATES TO ZERO +++++++++++ ")
580
+ assert self.use_ema
581
+ self.model_ema.reset_num_updates()
582
+
583
+ def make_cond_schedule(self, ):
584
+ self.cond_ids = torch.full(size=(self.num_timesteps,), fill_value=self.num_timesteps - 1, dtype=torch.long)
585
+ ids = torch.round(torch.linspace(0, self.num_timesteps - 1, self.num_timesteps_cond)).long()
586
+ self.cond_ids[:self.num_timesteps_cond] = ids
587
+
588
+ @rank_zero_only
589
+ @torch.no_grad()
590
+ def on_train_batch_start(self, batch, batch_idx, dataloader_idx):
591
+ # only for very first batch
592
+ if self.scale_by_std and self.current_epoch == 0 and self.global_step == 0 and batch_idx == 0 and not self.restarted_from_ckpt:
593
+ assert self.scale_factor == 1., 'rather not use custom rescaling and std-rescaling simultaneously'
594
+ # set rescale weight to 1./std of encodings
595
+ print("### USING STD-RESCALING ###")
596
+ x = super().get_input(batch, self.first_stage_key)
597
+ x = x.to(self.device)
598
+ encoder_posterior = self.encode_first_stage(x)
599
+ z = self.get_first_stage_encoding(encoder_posterior).detach()
600
+ del self.scale_factor
601
+ self.register_buffer('scale_factor', 1. / z.flatten().std())
602
+ print(f"setting self.scale_factor to {self.scale_factor}")
603
+ print("### USING STD-RESCALING ###")
604
+
605
+ def register_schedule(self,
606
+ given_betas=None, beta_schedule="linear", timesteps=1000,
607
+ linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3):
608
+ super().register_schedule(given_betas, beta_schedule, timesteps, linear_start, linear_end, cosine_s)
609
+
610
+ self.shorten_cond_schedule = self.num_timesteps_cond > 1
611
+ if self.shorten_cond_schedule:
612
+ self.make_cond_schedule()
613
+
614
+ def instantiate_first_stage(self, config):
615
+ model = instantiate_from_config(config)
616
+ self.first_stage_model = model.eval()
617
+ self.first_stage_model.train = disabled_train
618
+ for param in self.first_stage_model.parameters():
619
+ param.requires_grad = False
620
+
621
+ def instantiate_cond_stage(self, config):
622
+ if not self.cond_stage_trainable:
623
+ if config == "__is_first_stage__":
624
+ print("Using first stage also as cond stage.")
625
+ self.cond_stage_model = self.first_stage_model
626
+ elif config == "__is_unconditional__":
627
+ print(f"Training {self.__class__.__name__} as an unconditional model.")
628
+ self.cond_stage_model = None
629
+ # self.be_unconditional = True
630
+ else:
631
+ model = instantiate_from_config(config)
632
+ self.cond_stage_model = model.eval()
633
+ self.cond_stage_model.train = disabled_train
634
+ for param in self.cond_stage_model.parameters():
635
+ param.requires_grad = False
636
+ else:
637
+ assert config != '__is_first_stage__'
638
+ assert config != '__is_unconditional__'
639
+ model = instantiate_from_config(config)
640
+ self.cond_stage_model = model
641
+
642
+ def _get_denoise_row_from_list(self, samples, desc='', force_no_decoder_quantization=False):
643
+ denoise_row = []
644
+ for zd in tqdm(samples, desc=desc):
645
+ denoise_row.append(self.decode_first_stage(zd.to(self.device),
646
+ force_not_quantize=force_no_decoder_quantization))
647
+ n_imgs_per_row = len(denoise_row)
648
+ denoise_row = torch.stack(denoise_row) # n_log_step, n_row, C, H, W
649
+ denoise_grid = rearrange(denoise_row, 'n b c h w -> b n c h w')
650
+ denoise_grid = rearrange(denoise_grid, 'b n c h w -> (b n) c h w')
651
+ denoise_grid = make_grid(denoise_grid, nrow=n_imgs_per_row)
652
+ return denoise_grid
653
+
654
+ def get_first_stage_encoding(self, encoder_posterior):
655
+ if isinstance(encoder_posterior, DiagonalGaussianDistribution):
656
+ z = encoder_posterior.sample()
657
+ elif isinstance(encoder_posterior, torch.Tensor):
658
+ z = encoder_posterior
659
+ else:
660
+ raise NotImplementedError(f"encoder_posterior of type '{type(encoder_posterior)}' not yet implemented")
661
+ return self.scale_factor * z
662
+
663
+ def get_learned_conditioning(self, c):
664
+ if self.cond_stage_forward is None:
665
+ if hasattr(self.cond_stage_model, 'encode') and callable(self.cond_stage_model.encode):
666
+ c = self.cond_stage_model.encode(c)
667
+ if isinstance(c, DiagonalGaussianDistribution):
668
+ c = c.mode()
669
+ else:
670
+ c = self.cond_stage_model(c)
671
+ else:
672
+ assert hasattr(self.cond_stage_model, self.cond_stage_forward)
673
+ c = getattr(self.cond_stage_model, self.cond_stage_forward)(c)
674
+ return c
675
+
676
+ def meshgrid(self, h, w):
677
+ y = torch.arange(0, h).view(h, 1, 1).repeat(1, w, 1)
678
+ x = torch.arange(0, w).view(1, w, 1).repeat(h, 1, 1)
679
+
680
+ arr = torch.cat([y, x], dim=-1)
681
+ return arr
682
+
683
+ def delta_border(self, h, w):
684
+ """
685
+ :param h: height
686
+ :param w: width
687
+ :return: normalized distance to image border,
688
+ wtith min distance = 0 at border and max dist = 0.5 at image center
689
+ """
690
+ lower_right_corner = torch.tensor([h - 1, w - 1]).view(1, 1, 2)
691
+ arr = self.meshgrid(h, w) / lower_right_corner
692
+ dist_left_up = torch.min(arr, dim=-1, keepdims=True)[0]
693
+ dist_right_down = torch.min(1 - arr, dim=-1, keepdims=True)[0]
694
+ edge_dist = torch.min(torch.cat([dist_left_up, dist_right_down], dim=-1), dim=-1)[0]
695
+ return edge_dist
696
+
697
+ def get_weighting(self, h, w, Ly, Lx, device):
698
+ weighting = self.delta_border(h, w)
699
+ weighting = torch.clip(weighting, self.split_input_params["clip_min_weight"],
700
+ self.split_input_params["clip_max_weight"], )
701
+ weighting = weighting.view(1, h * w, 1).repeat(1, 1, Ly * Lx).to(device)
702
+
703
+ if self.split_input_params["tie_braker"]:
704
+ L_weighting = self.delta_border(Ly, Lx)
705
+ L_weighting = torch.clip(L_weighting,
706
+ self.split_input_params["clip_min_tie_weight"],
707
+ self.split_input_params["clip_max_tie_weight"])
708
+
709
+ L_weighting = L_weighting.view(1, 1, Ly * Lx).to(device)
710
+ weighting = weighting * L_weighting
711
+ return weighting
712
+
713
+ def get_fold_unfold(self, x, kernel_size, stride, uf=1, df=1): # todo load once not every time, shorten code
714
+ """
715
+ :param x: img of size (bs, c, h, w)
716
+ :return: n img crops of size (n, bs, c, kernel_size[0], kernel_size[1])
717
+ """
718
+ bs, nc, h, w = x.shape
719
+
720
+ # number of crops in image
721
+ Ly = (h - kernel_size[0]) // stride[0] + 1
722
+ Lx = (w - kernel_size[1]) // stride[1] + 1
723
+
724
+ if uf == 1 and df == 1:
725
+ fold_params = dict(kernel_size=kernel_size, dilation=1, padding=0, stride=stride)
726
+ unfold = torch.nn.Unfold(**fold_params)
727
+
728
+ fold = torch.nn.Fold(output_size=x.shape[2:], **fold_params)
729
+
730
+ weighting = self.get_weighting(kernel_size[0], kernel_size[1], Ly, Lx, x.device).to(x.dtype)
731
+ normalization = fold(weighting).view(1, 1, h, w) # normalizes the overlap
732
+ weighting = weighting.view((1, 1, kernel_size[0], kernel_size[1], Ly * Lx))
733
+
734
+ elif uf > 1 and df == 1:
735
+ fold_params = dict(kernel_size=kernel_size, dilation=1, padding=0, stride=stride)
736
+ unfold = torch.nn.Unfold(**fold_params)
737
+
738
+ fold_params2 = dict(kernel_size=(kernel_size[0] * uf, kernel_size[0] * uf),
739
+ dilation=1, padding=0,
740
+ stride=(stride[0] * uf, stride[1] * uf))
741
+ fold = torch.nn.Fold(output_size=(x.shape[2] * uf, x.shape[3] * uf), **fold_params2)
742
+
743
+ weighting = self.get_weighting(kernel_size[0] * uf, kernel_size[1] * uf, Ly, Lx, x.device).to(x.dtype)
744
+ normalization = fold(weighting).view(1, 1, h * uf, w * uf) # normalizes the overlap
745
+ weighting = weighting.view((1, 1, kernel_size[0] * uf, kernel_size[1] * uf, Ly * Lx))
746
+
747
+ elif df > 1 and uf == 1:
748
+ fold_params = dict(kernel_size=kernel_size, dilation=1, padding=0, stride=stride)
749
+ unfold = torch.nn.Unfold(**fold_params)
750
+
751
+ fold_params2 = dict(kernel_size=(kernel_size[0] // df, kernel_size[0] // df),
752
+ dilation=1, padding=0,
753
+ stride=(stride[0] // df, stride[1] // df))
754
+ fold = torch.nn.Fold(output_size=(x.shape[2] // df, x.shape[3] // df), **fold_params2)
755
+
756
+ weighting = self.get_weighting(kernel_size[0] // df, kernel_size[1] // df, Ly, Lx, x.device).to(x.dtype)
757
+ normalization = fold(weighting).view(1, 1, h // df, w // df) # normalizes the overlap
758
+ weighting = weighting.view((1, 1, kernel_size[0] // df, kernel_size[1] // df, Ly * Lx))
759
+
760
+ else:
761
+ raise NotImplementedError
762
+
763
+ return fold, unfold, normalization, weighting
764
+
765
+ @torch.no_grad()
766
+ def get_input(self, batch, k, return_first_stage_outputs=False, force_c_encode=False,
767
+ cond_key=None, return_original_cond=False, bs=None, return_x=False):
768
+ x = super().get_input(batch, k)
769
+ if bs is not None:
770
+ x = x[:bs]
771
+ x = x.to(self.device)
772
+ encoder_posterior = self.encode_first_stage(x)
773
+ z = self.get_first_stage_encoding(encoder_posterior).detach()
774
+
775
+ if self.model.conditioning_key is not None and not self.force_null_conditioning:
776
+ if cond_key is None:
777
+ cond_key = self.cond_stage_key
778
+ if cond_key != self.first_stage_key:
779
+ if cond_key in ['caption', 'coordinates_bbox', "txt"]:
780
+ xc = batch[cond_key]
781
+ elif cond_key in ['class_label', 'cls']:
782
+ xc = batch
783
+ else:
784
+ xc = super().get_input(batch, cond_key).to(self.device)
785
+ else:
786
+ xc = x
787
+ if not self.cond_stage_trainable or force_c_encode:
788
+ if isinstance(xc, dict) or isinstance(xc, list):
789
+ c = self.get_learned_conditioning(xc)
790
+ else:
791
+ c = self.get_learned_conditioning(xc.to(self.device))
792
+ else:
793
+ c = xc
794
+ if bs is not None:
795
+ c = c[:bs]
796
+
797
+ if self.use_positional_encodings:
798
+ pos_x, pos_y = self.compute_latent_shifts(batch)
799
+ ckey = __conditioning_keys__[self.model.conditioning_key]
800
+ c = {ckey: c, 'pos_x': pos_x, 'pos_y': pos_y}
801
+
802
+ else:
803
+ c = None
804
+ xc = None
805
+ if self.use_positional_encodings:
806
+ pos_x, pos_y = self.compute_latent_shifts(batch)
807
+ c = {'pos_x': pos_x, 'pos_y': pos_y}
808
+ out = [z, c]
809
+ if return_first_stage_outputs:
810
+ xrec = self.decode_first_stage(z)
811
+ out.extend([x, xrec])
812
+ if return_x:
813
+ out.extend([x])
814
+ if return_original_cond:
815
+ out.append(xc)
816
+ return out
817
+
818
+ @torch.no_grad()
819
+ def decode_first_stage(self, z, predict_cids=False, force_not_quantize=False):
820
+ if predict_cids:
821
+ if z.dim() == 4:
822
+ z = torch.argmax(z.exp(), dim=1).long()
823
+ z = self.first_stage_model.quantize.get_codebook_entry(z, shape=None)
824
+ z = rearrange(z, 'b h w c -> b c h w').contiguous()
825
+
826
+ z = 1. / self.scale_factor * z
827
+ return self.first_stage_model.decode(z)
828
+
829
+ @torch.no_grad()
830
+ def encode_first_stage(self, x):
831
+ return self.first_stage_model.encode(x)
832
+
833
+ def shared_step(self, batch, **kwargs):
834
+ x, c = self.get_input(batch, self.first_stage_key)
835
+ loss = self(x, c)
836
+ return loss
837
+
838
+ def forward(self, x, c, *args, **kwargs):
839
+ t = torch.randint(0, self.num_timesteps, (x.shape[0],), device=self.device).long()
840
+ if self.model.conditioning_key is not None:
841
+ assert c is not None
842
+ if self.cond_stage_trainable:
843
+ c = self.get_learned_conditioning(c)
844
+ if self.shorten_cond_schedule: # TODO: drop this option
845
+ tc = self.cond_ids[t].to(self.device)
846
+ c = self.q_sample(x_start=c, t=tc, noise=torch.randn_like(c.float()))
847
+ return self.p_losses(x, c, t, *args, **kwargs)
848
+
849
+ def apply_model(self, x_noisy, t, cond, return_ids=False):
850
+ if isinstance(cond, dict):
851
+ # hybrid case, cond is expected to be a dict
852
+ pass
853
+ else:
854
+ if not isinstance(cond, list):
855
+ cond = [cond]
856
+ key = 'c_concat' if self.model.conditioning_key == 'concat' else 'c_crossattn'
857
+ cond = {key: cond}
858
+
859
+ x_recon = self.model(x_noisy, t, **cond)
860
+
861
+ if isinstance(x_recon, tuple) and not return_ids:
862
+ return x_recon[0]
863
+ else:
864
+ return x_recon
865
+
866
+ def _predict_eps_from_xstart(self, x_t, t, pred_xstart):
867
+ return (extract_into_tensor(self.sqrt_recip_alphas_cumprod, t, x_t.shape) * x_t - pred_xstart) / \
868
+ extract_into_tensor(self.sqrt_recipm1_alphas_cumprod, t, x_t.shape)
869
+
870
+ def _prior_bpd(self, x_start):
871
+ """
872
+ Get the prior KL term for the variational lower-bound, measured in
873
+ bits-per-dim.
874
+ This term can't be optimized, as it only depends on the encoder.
875
+ :param x_start: the [N x C x ...] tensor of inputs.
876
+ :return: a batch of [N] KL values (in bits), one per batch element.
877
+ """
878
+ batch_size = x_start.shape[0]
879
+ t = torch.tensor([self.num_timesteps - 1] * batch_size, device=x_start.device)
880
+ qt_mean, _, qt_log_variance = self.q_mean_variance(x_start, t)
881
+ kl_prior = normal_kl(mean1=qt_mean, logvar1=qt_log_variance, mean2=0.0, logvar2=0.0)
882
+ return mean_flat(kl_prior) / np.log(2.0)
883
+
884
+ def p_losses(self, x_start, cond, t, noise=None):
885
+ noise = default(noise, lambda: torch.randn_like(x_start))
886
+ x_noisy = self.q_sample(x_start=x_start, t=t, noise=noise)
887
+ model_output = self.apply_model(x_noisy, t, cond)
888
+
889
+ loss_dict = {}
890
+ prefix = 'train' if self.training else 'val'
891
+
892
+ if self.parameterization == "x0":
893
+ target = x_start
894
+ elif self.parameterization == "eps":
895
+ target = noise
896
+ elif self.parameterization == "v":
897
+ target = self.get_v(x_start, noise, t)
898
+ else:
899
+ raise NotImplementedError()
900
+
901
+ loss_simple = self.get_loss(model_output, target, mean=False).mean([1, 2, 3])
902
+ loss_dict.update({f'{prefix}/loss_simple': loss_simple.mean()})
903
+
904
+ logvar_t = self.logvar[t].to(self.device)
905
+ loss = loss_simple / torch.exp(logvar_t) + logvar_t
906
+ # loss = loss_simple / torch.exp(self.logvar) + self.logvar
907
+ if self.learn_logvar:
908
+ loss_dict.update({f'{prefix}/loss_gamma': loss.mean()})
909
+ loss_dict.update({'logvar': self.logvar.data.mean()})
910
+
911
+ loss = self.l_simple_weight * loss.mean()
912
+
913
+ loss_vlb = self.get_loss(model_output, target, mean=False).mean(dim=(1, 2, 3))
914
+ loss_vlb = (self.lvlb_weights[t] * loss_vlb).mean()
915
+ loss_dict.update({f'{prefix}/loss_vlb': loss_vlb})
916
+ loss += (self.original_elbo_weight * loss_vlb)
917
+ loss_dict.update({f'{prefix}/loss': loss})
918
+
919
+ return loss, loss_dict
920
+
921
+ def p_mean_variance(self, x, c, t, clip_denoised: bool, return_codebook_ids=False, quantize_denoised=False,
922
+ return_x0=False, score_corrector=None, corrector_kwargs=None):
923
+ t_in = t
924
+ model_out = self.apply_model(x, t_in, c, return_ids=return_codebook_ids)
925
+
926
+ if score_corrector is not None:
927
+ assert self.parameterization == "eps"
928
+ model_out = score_corrector.modify_score(self, model_out, x, t, c, **corrector_kwargs)
929
+
930
+ if return_codebook_ids:
931
+ model_out, logits = model_out
932
+
933
+ if self.parameterization == "eps":
934
+ x_recon = self.predict_start_from_noise(x, t=t, noise=model_out)
935
+ elif self.parameterization == "x0":
936
+ x_recon = model_out
937
+ else:
938
+ raise NotImplementedError()
939
+
940
+ if clip_denoised:
941
+ x_recon.clamp_(-1., 1.)
942
+ if quantize_denoised:
943
+ x_recon, _, [_, _, indices] = self.first_stage_model.quantize(x_recon)
944
+ model_mean, posterior_variance, posterior_log_variance = self.q_posterior(x_start=x_recon, x_t=x, t=t)
945
+ if return_codebook_ids:
946
+ return model_mean, posterior_variance, posterior_log_variance, logits
947
+ elif return_x0:
948
+ return model_mean, posterior_variance, posterior_log_variance, x_recon
949
+ else:
950
+ return model_mean, posterior_variance, posterior_log_variance
951
+
952
+ @torch.no_grad()
953
+ def p_sample(self, x, c, t, clip_denoised=False, repeat_noise=False,
954
+ return_codebook_ids=False, quantize_denoised=False, return_x0=False,
955
+ temperature=1., noise_dropout=0., score_corrector=None, corrector_kwargs=None):
956
+ b, *_, device = *x.shape, x.device
957
+ outputs = self.p_mean_variance(x=x, c=c, t=t, clip_denoised=clip_denoised,
958
+ return_codebook_ids=return_codebook_ids,
959
+ quantize_denoised=quantize_denoised,
960
+ return_x0=return_x0,
961
+ score_corrector=score_corrector, corrector_kwargs=corrector_kwargs)
962
+ if return_codebook_ids:
963
+ raise DeprecationWarning("Support dropped.")
964
+ model_mean, _, model_log_variance, logits = outputs
965
+ elif return_x0:
966
+ model_mean, _, model_log_variance, x0 = outputs
967
+ else:
968
+ model_mean, _, model_log_variance = outputs
969
+
970
+ noise = noise_like(x.shape, device, repeat_noise) * temperature
971
+ if noise_dropout > 0.:
972
+ noise = torch.nn.functional.dropout(noise, p=noise_dropout)
973
+ # no noise when t == 0
974
+ nonzero_mask = (1 - (t == 0).float()).reshape(b, *((1,) * (len(x.shape) - 1)))
975
+
976
+ if return_codebook_ids:
977
+ return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise, logits.argmax(dim=1)
978
+ if return_x0:
979
+ return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise, x0
980
+ else:
981
+ return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise
982
+
983
+ @torch.no_grad()
984
+ def progressive_denoising(self, cond, shape, verbose=True, callback=None, quantize_denoised=False,
985
+ img_callback=None, mask=None, x0=None, temperature=1., noise_dropout=0.,
986
+ score_corrector=None, corrector_kwargs=None, batch_size=None, x_T=None, start_T=None,
987
+ log_every_t=None):
988
+ if not log_every_t:
989
+ log_every_t = self.log_every_t
990
+ timesteps = self.num_timesteps
991
+ if batch_size is not None:
992
+ b = batch_size if batch_size is not None else shape[0]
993
+ shape = [batch_size] + list(shape)
994
+ else:
995
+ b = batch_size = shape[0]
996
+ if x_T is None:
997
+ img = torch.randn(shape, device=self.device)
998
+ else:
999
+ img = x_T
1000
+ intermediates = []
1001
+ if cond is not None:
1002
+ if isinstance(cond, dict):
1003
+ cond = {key: cond[key][:batch_size] if not isinstance(cond[key], list) else
1004
+ list(map(lambda x: x[:batch_size], cond[key])) for key in cond}
1005
+ else:
1006
+ cond = [c[:batch_size] for c in cond] if isinstance(cond, list) else cond[:batch_size]
1007
+
1008
+ if start_T is not None:
1009
+ timesteps = min(timesteps, start_T)
1010
+ iterator = tqdm(reversed(range(0, timesteps)), desc='Progressive Generation',
1011
+ total=timesteps) if verbose else reversed(
1012
+ range(0, timesteps))
1013
+ if type(temperature) == float:
1014
+ temperature = [temperature] * timesteps
1015
+
1016
+ for i in iterator:
1017
+ ts = torch.full((b,), i, device=self.device, dtype=torch.long)
1018
+ if self.shorten_cond_schedule:
1019
+ assert self.model.conditioning_key != 'hybrid'
1020
+ tc = self.cond_ids[ts].to(cond.device)
1021
+ cond = self.q_sample(x_start=cond, t=tc, noise=torch.randn_like(cond))
1022
+
1023
+ img, x0_partial = self.p_sample(img, cond, ts,
1024
+ clip_denoised=self.clip_denoised,
1025
+ quantize_denoised=quantize_denoised, return_x0=True,
1026
+ temperature=temperature[i], noise_dropout=noise_dropout,
1027
+ score_corrector=score_corrector, corrector_kwargs=corrector_kwargs)
1028
+ if mask is not None:
1029
+ assert x0 is not None
1030
+ img_orig = self.q_sample(x0, ts)
1031
+ img = img_orig * mask + (1. - mask) * img
1032
+
1033
+ if i % log_every_t == 0 or i == timesteps - 1:
1034
+ intermediates.append(x0_partial)
1035
+ if callback: callback(i)
1036
+ if img_callback: img_callback(img, i)
1037
+ return img, intermediates
1038
+
1039
+ @torch.no_grad()
1040
+ def p_sample_loop(self, cond, shape, return_intermediates=False,
1041
+ x_T=None, verbose=True, callback=None, timesteps=None, quantize_denoised=False,
1042
+ mask=None, x0=None, img_callback=None, start_T=None,
1043
+ log_every_t=None):
1044
+
1045
+ if not log_every_t:
1046
+ log_every_t = self.log_every_t
1047
+ device = self.betas.device
1048
+ b = shape[0]
1049
+ if x_T is None:
1050
+ img = torch.randn(shape, device=device)
1051
+ else:
1052
+ img = x_T
1053
+
1054
+ intermediates = [img]
1055
+ if timesteps is None:
1056
+ timesteps = self.num_timesteps
1057
+
1058
+ if start_T is not None:
1059
+ timesteps = min(timesteps, start_T)
1060
+ iterator = tqdm(reversed(range(0, timesteps)), desc='Sampling t', total=timesteps) if verbose else reversed(
1061
+ range(0, timesteps))
1062
+
1063
+ if mask is not None:
1064
+ assert x0 is not None
1065
+ assert x0.shape[2:3] == mask.shape[2:3] # spatial size has to match
1066
+
1067
+ for i in iterator:
1068
+ ts = torch.full((b,), i, device=device, dtype=torch.long)
1069
+ if self.shorten_cond_schedule:
1070
+ assert self.model.conditioning_key != 'hybrid'
1071
+ tc = self.cond_ids[ts].to(cond.device)
1072
+ cond = self.q_sample(x_start=cond, t=tc, noise=torch.randn_like(cond))
1073
+
1074
+ img = self.p_sample(img, cond, ts,
1075
+ clip_denoised=self.clip_denoised,
1076
+ quantize_denoised=quantize_denoised)
1077
+ if mask is not None:
1078
+ img_orig = self.q_sample(x0, ts)
1079
+ img = img_orig * mask + (1. - mask) * img
1080
+
1081
+ if i % log_every_t == 0 or i == timesteps - 1:
1082
+ intermediates.append(img)
1083
+ if callback: callback(i)
1084
+ if img_callback: img_callback(img, i)
1085
+
1086
+ if return_intermediates:
1087
+ return img, intermediates
1088
+ return img
1089
+
1090
+ @torch.no_grad()
1091
+ def sample(self, cond, batch_size=16, return_intermediates=False, x_T=None,
1092
+ verbose=True, timesteps=None, quantize_denoised=False,
1093
+ mask=None, x0=None, shape=None, **kwargs):
1094
+ if shape is None:
1095
+ shape = (batch_size, self.channels, self.image_size, self.image_size)
1096
+ if cond is not None:
1097
+ if isinstance(cond, dict):
1098
+ cond = {key: cond[key][:batch_size] if not isinstance(cond[key], list) else
1099
+ list(map(lambda x: x[:batch_size], cond[key])) for key in cond}
1100
+ else:
1101
+ cond = [c[:batch_size] for c in cond] if isinstance(cond, list) else cond[:batch_size]
1102
+ return self.p_sample_loop(cond,
1103
+ shape,
1104
+ return_intermediates=return_intermediates, x_T=x_T,
1105
+ verbose=verbose, timesteps=timesteps, quantize_denoised=quantize_denoised,
1106
+ mask=mask, x0=x0)
1107
+
1108
+ @torch.no_grad()
1109
+ def sample_log(self, cond, batch_size, ddim, ddim_steps, **kwargs):
1110
+ if ddim:
1111
+ ddim_sampler = DDIMSampler(self)
1112
+ shape = (self.channels, self.image_size, self.image_size)
1113
+ samples, intermediates = ddim_sampler.sample(ddim_steps, batch_size,
1114
+ shape, cond, verbose=False, **kwargs)
1115
+
1116
+ else:
1117
+ samples, intermediates = self.sample(cond=cond, batch_size=batch_size,
1118
+ return_intermediates=True, **kwargs)
1119
+
1120
+ return samples, intermediates
1121
+
1122
+ @torch.no_grad()
1123
+ def get_unconditional_conditioning(self, batch_size, null_label=None):
1124
+ if null_label is not None:
1125
+ xc = null_label
1126
+ if isinstance(xc, ListConfig):
1127
+ xc = list(xc)
1128
+ if isinstance(xc, dict) or isinstance(xc, list):
1129
+ c = self.get_learned_conditioning(xc)
1130
+ else:
1131
+ if hasattr(xc, "to"):
1132
+ xc = xc.to(self.device)
1133
+ c = self.get_learned_conditioning(xc)
1134
+ else:
1135
+ if self.cond_stage_key in ["class_label", "cls"]:
1136
+ xc = self.cond_stage_model.get_unconditional_conditioning(batch_size, device=self.device)
1137
+ return self.get_learned_conditioning(xc)
1138
+ else:
1139
+ raise NotImplementedError("todo")
1140
+ if isinstance(c, list): # in case the encoder gives us a list
1141
+ for i in range(len(c)):
1142
+ c[i] = repeat(c[i], '1 ... -> b ...', b=batch_size).to(self.device)
1143
+ else:
1144
+ c = repeat(c, '1 ... -> b ...', b=batch_size).to(self.device)
1145
+ return c
1146
+
1147
+ @torch.no_grad()
1148
+ def log_images(self, batch, N=8, n_row=4, sample=True, ddim_steps=50, ddim_eta=0., return_keys=None,
1149
+ quantize_denoised=True, inpaint=True, plot_denoise_rows=False, plot_progressive_rows=True,
1150
+ plot_diffusion_rows=True, unconditional_guidance_scale=1., unconditional_guidance_label=None,
1151
+ use_ema_scope=True,
1152
+ **kwargs):
1153
+ ema_scope = self.ema_scope if use_ema_scope else nullcontext
1154
+ use_ddim = ddim_steps is not None
1155
+
1156
+ log = dict()
1157
+ z, c, x, xrec, xc = self.get_input(batch, self.first_stage_key,
1158
+ return_first_stage_outputs=True,
1159
+ force_c_encode=True,
1160
+ return_original_cond=True,
1161
+ bs=N)
1162
+ N = min(x.shape[0], N)
1163
+ n_row = min(x.shape[0], n_row)
1164
+ log["inputs"] = x
1165
+ log["reconstruction"] = xrec
1166
+ if self.model.conditioning_key is not None:
1167
+ if hasattr(self.cond_stage_model, "decode"):
1168
+ xc = self.cond_stage_model.decode(c)
1169
+ log["conditioning"] = xc
1170
+ elif self.cond_stage_key in ["caption", "txt"]:
1171
+ xc = log_txt_as_img((x.shape[2], x.shape[3]), batch[self.cond_stage_key], size=x.shape[2] // 25)
1172
+ log["conditioning"] = xc
1173
+ elif self.cond_stage_key in ['class_label', "cls"]:
1174
+ try:
1175
+ xc = log_txt_as_img((x.shape[2], x.shape[3]), batch["human_label"], size=x.shape[2] // 25)
1176
+ log['conditioning'] = xc
1177
+ except KeyError:
1178
+ # probably no "human_label" in batch
1179
+ pass
1180
+ elif isimage(xc):
1181
+ log["conditioning"] = xc
1182
+ if ismap(xc):
1183
+ log["original_conditioning"] = self.to_rgb(xc)
1184
+
1185
+ if plot_diffusion_rows:
1186
+ # get diffusion row
1187
+ diffusion_row = list()
1188
+ z_start = z[:n_row]
1189
+ for t in range(self.num_timesteps):
1190
+ if t % self.log_every_t == 0 or t == self.num_timesteps - 1:
1191
+ t = repeat(torch.tensor([t]), '1 -> b', b=n_row)
1192
+ t = t.to(self.device).long()
1193
+ noise = torch.randn_like(z_start)
1194
+ z_noisy = self.q_sample(x_start=z_start, t=t, noise=noise)
1195
+ diffusion_row.append(self.decode_first_stage(z_noisy))
1196
+
1197
+ diffusion_row = torch.stack(diffusion_row) # n_log_step, n_row, C, H, W
1198
+ diffusion_grid = rearrange(diffusion_row, 'n b c h w -> b n c h w')
1199
+ diffusion_grid = rearrange(diffusion_grid, 'b n c h w -> (b n) c h w')
1200
+ diffusion_grid = make_grid(diffusion_grid, nrow=diffusion_row.shape[0])
1201
+ log["diffusion_row"] = diffusion_grid
1202
+
1203
+ if sample:
1204
+ # get denoise row
1205
+ with ema_scope("Sampling"):
1206
+ samples, z_denoise_row = self.sample_log(cond=c, batch_size=N, ddim=use_ddim,
1207
+ ddim_steps=ddim_steps, eta=ddim_eta)
1208
+ # samples, z_denoise_row = self.sample(cond=c, batch_size=N, return_intermediates=True)
1209
+ x_samples = self.decode_first_stage(samples)
1210
+ log["samples"] = x_samples
1211
+ if plot_denoise_rows:
1212
+ denoise_grid = self._get_denoise_row_from_list(z_denoise_row)
1213
+ log["denoise_row"] = denoise_grid
1214
+
1215
+ if quantize_denoised and not isinstance(self.first_stage_model, AutoencoderKL) and not isinstance(
1216
+ self.first_stage_model, IdentityFirstStage):
1217
+ # also display when quantizing x0 while sampling
1218
+ with ema_scope("Plotting Quantized Denoised"):
1219
+ samples, z_denoise_row = self.sample_log(cond=c, batch_size=N, ddim=use_ddim,
1220
+ ddim_steps=ddim_steps, eta=ddim_eta,
1221
+ quantize_denoised=True)
1222
+ # samples, z_denoise_row = self.sample(cond=c, batch_size=N, return_intermediates=True,
1223
+ # quantize_denoised=True)
1224
+ x_samples = self.decode_first_stage(samples.to(self.device))
1225
+ log["samples_x0_quantized"] = x_samples
1226
+
1227
+ if unconditional_guidance_scale > 1.0:
1228
+ uc = self.get_unconditional_conditioning(N, unconditional_guidance_label)
1229
+ if self.model.conditioning_key == "crossattn-adm":
1230
+ uc = {"c_crossattn": [uc], "c_adm": c["c_adm"]}
1231
+ with ema_scope("Sampling with classifier-free guidance"):
1232
+ samples_cfg, _ = self.sample_log(cond=c, batch_size=N, ddim=use_ddim,
1233
+ ddim_steps=ddim_steps, eta=ddim_eta,
1234
+ unconditional_guidance_scale=unconditional_guidance_scale,
1235
+ unconditional_conditioning=uc,
1236
+ )
1237
+ x_samples_cfg = self.decode_first_stage(samples_cfg)
1238
+ log[f"samples_cfg_scale_{unconditional_guidance_scale:.2f}"] = x_samples_cfg
1239
+
1240
+ if inpaint:
1241
+ # make a simple center square
1242
+ b, h, w = z.shape[0], z.shape[2], z.shape[3]
1243
+ mask = torch.ones(N, h, w).to(self.device)
1244
+ # zeros will be filled in
1245
+ mask[:, h // 4:3 * h // 4, w // 4:3 * w // 4] = 0.
1246
+ mask = mask[:, None, ...]
1247
+ with ema_scope("Plotting Inpaint"):
1248
+ samples, _ = self.sample_log(cond=c, batch_size=N, ddim=use_ddim, eta=ddim_eta,
1249
+ ddim_steps=ddim_steps, x0=z[:N], mask=mask)
1250
+ x_samples = self.decode_first_stage(samples.to(self.device))
1251
+ log["samples_inpainting"] = x_samples
1252
+ log["mask"] = mask
1253
+
1254
+ # outpaint
1255
+ mask = 1. - mask
1256
+ with ema_scope("Plotting Outpaint"):
1257
+ samples, _ = self.sample_log(cond=c, batch_size=N, ddim=use_ddim, eta=ddim_eta,
1258
+ ddim_steps=ddim_steps, x0=z[:N], mask=mask)
1259
+ x_samples = self.decode_first_stage(samples.to(self.device))
1260
+ log["samples_outpainting"] = x_samples
1261
+
1262
+ if plot_progressive_rows:
1263
+ with ema_scope("Plotting Progressives"):
1264
+ img, progressives = self.progressive_denoising(c,
1265
+ shape=(self.channels, self.image_size, self.image_size),
1266
+ batch_size=N)
1267
+ prog_row = self._get_denoise_row_from_list(progressives, desc="Progressive Generation")
1268
+ log["progressive_row"] = prog_row
1269
+
1270
+ if return_keys:
1271
+ if np.intersect1d(list(log.keys()), return_keys).shape[0] == 0:
1272
+ return log
1273
+ else:
1274
+ return {key: log[key] for key in return_keys}
1275
+ return log
1276
+
1277
+ def configure_optimizers(self):
1278
+ lr = self.learning_rate
1279
+ params = list(self.model.parameters())
1280
+ if self.cond_stage_trainable:
1281
+ print(f"{self.__class__.__name__}: Also optimizing conditioner params!")
1282
+ params = params + list(self.cond_stage_model.parameters())
1283
+ if self.learn_logvar:
1284
+ print('Diffusion model optimizing logvar')
1285
+ params.append(self.logvar)
1286
+ opt = torch.optim.AdamW(params, lr=lr)
1287
+ if self.use_scheduler:
1288
+ assert 'target' in self.scheduler_config
1289
+ scheduler = instantiate_from_config(self.scheduler_config)
1290
+
1291
+ print("Setting up LambdaLR scheduler...")
1292
+ scheduler = [
1293
+ {
1294
+ 'scheduler': LambdaLR(opt, lr_lambda=scheduler.schedule),
1295
+ 'interval': 'step',
1296
+ 'frequency': 1
1297
+ }]
1298
+ return [opt], scheduler
1299
+ return opt
1300
+
1301
+ @torch.no_grad()
1302
+ def to_rgb(self, x):
1303
+ x = x.float()
1304
+ if not hasattr(self, "colorize"):
1305
+ self.colorize = torch.randn(3, x.shape[1], 1, 1).to(x)
1306
+ x = nn.functional.conv2d(x, weight=self.colorize)
1307
+ x = 2. * (x - x.min()) / (x.max() - x.min()) - 1.
1308
+ return x
1309
+
1310
+
1311
+ class DiffusionWrapper(pl.LightningModule):
1312
+ def __init__(self, diff_model_config, conditioning_key):
1313
+ super().__init__()
1314
+ self.sequential_cross_attn = diff_model_config.pop("sequential_crossattn", False)
1315
+ self.diffusion_model = instantiate_from_config(diff_model_config)
1316
+ self.conditioning_key = conditioning_key
1317
+ assert self.conditioning_key in [None, 'concat', 'crossattn', 'hybrid', 'adm', 'hybrid-adm', 'crossattn-adm']
1318
+
1319
+ def forward(self, x, t, c_concat: list = None, c_crossattn: list = None, c_adm=None):
1320
+ if self.conditioning_key is None:
1321
+ out = self.diffusion_model(x, t)
1322
+ elif self.conditioning_key == 'concat':
1323
+ xc = torch.cat([x] + c_concat, dim=1)
1324
+ out = self.diffusion_model(xc, t)
1325
+ elif self.conditioning_key == 'crossattn':
1326
+ if not self.sequential_cross_attn:
1327
+ cc = torch.cat(c_crossattn, 1)
1328
+ else:
1329
+ cc = c_crossattn
1330
+ if hasattr(self, "scripted_diffusion_model"):
1331
+ # TorchScript changes names of the arguments
1332
+ # with argument cc defined as context=cc scripted model will produce
1333
+ # an error: RuntimeError: forward() is missing value for argument 'argument_3'.
1334
+ out = self.scripted_diffusion_model(x, t, cc)
1335
+ else:
1336
+ out = self.diffusion_model(x, t, context=cc)
1337
+ elif self.conditioning_key == 'hybrid':
1338
+ xc = torch.cat([x] + c_concat, dim=1)
1339
+ cc = torch.cat(c_crossattn, 1)
1340
+ out = self.diffusion_model(xc, t, context=cc)
1341
+ elif self.conditioning_key == 'hybrid-adm':
1342
+ assert c_adm is not None
1343
+ xc = torch.cat([x] + c_concat, dim=1)
1344
+ cc = torch.cat(c_crossattn, 1)
1345
+ out = self.diffusion_model(xc, t, context=cc, y=c_adm)
1346
+ elif self.conditioning_key == 'crossattn-adm':
1347
+ assert c_adm is not None
1348
+ cc = torch.cat(c_crossattn, 1)
1349
+ out = self.diffusion_model(x, t, context=cc, y=c_adm)
1350
+ elif self.conditioning_key == 'adm':
1351
+ cc = c_crossattn[0]
1352
+ out = self.diffusion_model(x, t, y=cc)
1353
+ else:
1354
+ raise NotImplementedError()
1355
+
1356
+ return out
1357
+
1358
+
1359
+ class LatentUpscaleDiffusion(LatentDiffusion):
1360
+ def __init__(self, *args, low_scale_config, low_scale_key="LR", noise_level_key=None, **kwargs):
1361
+ super().__init__(*args, **kwargs)
1362
+ # assumes that neither the cond_stage nor the low_scale_model contain trainable params
1363
+ assert not self.cond_stage_trainable
1364
+ self.instantiate_low_stage(low_scale_config)
1365
+ self.low_scale_key = low_scale_key
1366
+ self.noise_level_key = noise_level_key
1367
+
1368
+ def instantiate_low_stage(self, config):
1369
+ model = instantiate_from_config(config)
1370
+ self.low_scale_model = model.eval()
1371
+ self.low_scale_model.train = disabled_train
1372
+ for param in self.low_scale_model.parameters():
1373
+ param.requires_grad = False
1374
+
1375
+ @torch.no_grad()
1376
+ def get_input(self, batch, k, cond_key=None, bs=None, log_mode=False):
1377
+ if not log_mode:
1378
+ z, c = super().get_input(batch, k, force_c_encode=True, bs=bs)
1379
+ else:
1380
+ z, c, x, xrec, xc = super().get_input(batch, self.first_stage_key, return_first_stage_outputs=True,
1381
+ force_c_encode=True, return_original_cond=True, bs=bs)
1382
+ x_low = batch[self.low_scale_key][:bs]
1383
+ x_low = rearrange(x_low, 'b h w c -> b c h w')
1384
+ x_low = x_low.to(memory_format=torch.contiguous_format).float()
1385
+ zx, noise_level = self.low_scale_model(x_low)
1386
+ if self.noise_level_key is not None:
1387
+ # get noise level from batch instead, e.g. when extracting a custom noise level for bsr
1388
+ raise NotImplementedError('TODO')
1389
+
1390
+ all_conds = {"c_concat": [zx], "c_crossattn": [c], "c_adm": noise_level}
1391
+ if log_mode:
1392
+ # TODO: maybe disable if too expensive
1393
+ x_low_rec = self.low_scale_model.decode(zx)
1394
+ return z, all_conds, x, xrec, xc, x_low, x_low_rec, noise_level
1395
+ return z, all_conds
1396
+
1397
+ @torch.no_grad()
1398
+ def log_images(self, batch, N=8, n_row=4, sample=True, ddim_steps=200, ddim_eta=1., return_keys=None,
1399
+ plot_denoise_rows=False, plot_progressive_rows=True, plot_diffusion_rows=True,
1400
+ unconditional_guidance_scale=1., unconditional_guidance_label=None, use_ema_scope=True,
1401
+ **kwargs):
1402
+ ema_scope = self.ema_scope if use_ema_scope else nullcontext
1403
+ use_ddim = ddim_steps is not None
1404
+
1405
+ log = dict()
1406
+ z, c, x, xrec, xc, x_low, x_low_rec, noise_level = self.get_input(batch, self.first_stage_key, bs=N,
1407
+ log_mode=True)
1408
+ N = min(x.shape[0], N)
1409
+ n_row = min(x.shape[0], n_row)
1410
+ log["inputs"] = x
1411
+ log["reconstruction"] = xrec
1412
+ log["x_lr"] = x_low
1413
+ log[f"x_lr_rec_@noise_levels{'-'.join(map(lambda x: str(x), list(noise_level.cpu().numpy())))}"] = x_low_rec
1414
+ if self.model.conditioning_key is not None:
1415
+ if hasattr(self.cond_stage_model, "decode"):
1416
+ xc = self.cond_stage_model.decode(c)
1417
+ log["conditioning"] = xc
1418
+ elif self.cond_stage_key in ["caption", "txt"]:
1419
+ xc = log_txt_as_img((x.shape[2], x.shape[3]), batch[self.cond_stage_key], size=x.shape[2] // 25)
1420
+ log["conditioning"] = xc
1421
+ elif self.cond_stage_key in ['class_label', 'cls']:
1422
+ xc = log_txt_as_img((x.shape[2], x.shape[3]), batch["human_label"], size=x.shape[2] // 25)
1423
+ log['conditioning'] = xc
1424
+ elif isimage(xc):
1425
+ log["conditioning"] = xc
1426
+ if ismap(xc):
1427
+ log["original_conditioning"] = self.to_rgb(xc)
1428
+
1429
+ if plot_diffusion_rows:
1430
+ # get diffusion row
1431
+ diffusion_row = list()
1432
+ z_start = z[:n_row]
1433
+ for t in range(self.num_timesteps):
1434
+ if t % self.log_every_t == 0 or t == self.num_timesteps - 1:
1435
+ t = repeat(torch.tensor([t]), '1 -> b', b=n_row)
1436
+ t = t.to(self.device).long()
1437
+ noise = torch.randn_like(z_start)
1438
+ z_noisy = self.q_sample(x_start=z_start, t=t, noise=noise)
1439
+ diffusion_row.append(self.decode_first_stage(z_noisy))
1440
+
1441
+ diffusion_row = torch.stack(diffusion_row) # n_log_step, n_row, C, H, W
1442
+ diffusion_grid = rearrange(diffusion_row, 'n b c h w -> b n c h w')
1443
+ diffusion_grid = rearrange(diffusion_grid, 'b n c h w -> (b n) c h w')
1444
+ diffusion_grid = make_grid(diffusion_grid, nrow=diffusion_row.shape[0])
1445
+ log["diffusion_row"] = diffusion_grid
1446
+
1447
+ if sample:
1448
+ # get denoise row
1449
+ with ema_scope("Sampling"):
1450
+ samples, z_denoise_row = self.sample_log(cond=c, batch_size=N, ddim=use_ddim,
1451
+ ddim_steps=ddim_steps, eta=ddim_eta)
1452
+ # samples, z_denoise_row = self.sample(cond=c, batch_size=N, return_intermediates=True)
1453
+ x_samples = self.decode_first_stage(samples)
1454
+ log["samples"] = x_samples
1455
+ if plot_denoise_rows:
1456
+ denoise_grid = self._get_denoise_row_from_list(z_denoise_row)
1457
+ log["denoise_row"] = denoise_grid
1458
+
1459
+ if unconditional_guidance_scale > 1.0:
1460
+ uc_tmp = self.get_unconditional_conditioning(N, unconditional_guidance_label)
1461
+ # TODO explore better "unconditional" choices for the other keys
1462
+ # maybe guide away from empty text label and highest noise level and maximally degraded zx?
1463
+ uc = dict()
1464
+ for k in c:
1465
+ if k == "c_crossattn":
1466
+ assert isinstance(c[k], list) and len(c[k]) == 1
1467
+ uc[k] = [uc_tmp]
1468
+ elif k == "c_adm": # todo: only run with text-based guidance?
1469
+ assert isinstance(c[k], torch.Tensor)
1470
+ #uc[k] = torch.ones_like(c[k]) * self.low_scale_model.max_noise_level
1471
+ uc[k] = c[k]
1472
+ elif isinstance(c[k], list):
1473
+ uc[k] = [c[k][i] for i in range(len(c[k]))]
1474
+ else:
1475
+ uc[k] = c[k]
1476
+
1477
+ with ema_scope("Sampling with classifier-free guidance"):
1478
+ samples_cfg, _ = self.sample_log(cond=c, batch_size=N, ddim=use_ddim,
1479
+ ddim_steps=ddim_steps, eta=ddim_eta,
1480
+ unconditional_guidance_scale=unconditional_guidance_scale,
1481
+ unconditional_conditioning=uc,
1482
+ )
1483
+ x_samples_cfg = self.decode_first_stage(samples_cfg)
1484
+ log[f"samples_cfg_scale_{unconditional_guidance_scale:.2f}"] = x_samples_cfg
1485
+
1486
+ if plot_progressive_rows:
1487
+ with ema_scope("Plotting Progressives"):
1488
+ img, progressives = self.progressive_denoising(c,
1489
+ shape=(self.channels, self.image_size, self.image_size),
1490
+ batch_size=N)
1491
+ prog_row = self._get_denoise_row_from_list(progressives, desc="Progressive Generation")
1492
+ log["progressive_row"] = prog_row
1493
+
1494
+ return log
1495
+
1496
+
1497
+ class LatentFinetuneDiffusion(LatentDiffusion):
1498
+ """
1499
+ Basis for different finetunas, such as inpainting or depth2image
1500
+ To disable finetuning mode, set finetune_keys to None
1501
+ """
1502
+
1503
+ def __init__(self,
1504
+ concat_keys: tuple,
1505
+ finetune_keys=("model.diffusion_model.input_blocks.0.0.weight",
1506
+ "model_ema.diffusion_modelinput_blocks00weight"
1507
+ ),
1508
+ keep_finetune_dims=4,
1509
+ # if model was trained without concat mode before and we would like to keep these channels
1510
+ c_concat_log_start=None, # to log reconstruction of c_concat codes
1511
+ c_concat_log_end=None,
1512
+ *args, **kwargs
1513
+ ):
1514
+ ckpt_path = kwargs.pop("ckpt_path", None)
1515
+ ignore_keys = kwargs.pop("ignore_keys", list())
1516
+ super().__init__(*args, **kwargs)
1517
+ self.finetune_keys = finetune_keys
1518
+ self.concat_keys = concat_keys
1519
+ self.keep_dims = keep_finetune_dims
1520
+ self.c_concat_log_start = c_concat_log_start
1521
+ self.c_concat_log_end = c_concat_log_end
1522
+ if exists(self.finetune_keys): assert exists(ckpt_path), 'can only finetune from a given checkpoint'
1523
+ if exists(ckpt_path):
1524
+ self.init_from_ckpt(ckpt_path, ignore_keys)
1525
+
1526
+ def init_from_ckpt(self, path, ignore_keys=list(), only_model=False):
1527
+ sd = torch.load(path, map_location="cpu")
1528
+ if "state_dict" in list(sd.keys()):
1529
+ sd = sd["state_dict"]
1530
+ keys = list(sd.keys())
1531
+ for k in keys:
1532
+ for ik in ignore_keys:
1533
+ if k.startswith(ik):
1534
+ print("Deleting key {} from state_dict.".format(k))
1535
+ del sd[k]
1536
+
1537
+ # make it explicit, finetune by including extra input channels
1538
+ if exists(self.finetune_keys) and k in self.finetune_keys:
1539
+ new_entry = None
1540
+ for name, param in self.named_parameters():
1541
+ if name in self.finetune_keys:
1542
+ print(
1543
+ f"modifying key '{name}' and keeping its original {self.keep_dims} (channels) dimensions only")
1544
+ new_entry = torch.zeros_like(param) # zero init
1545
+ assert exists(new_entry), 'did not find matching parameter to modify'
1546
+ new_entry[:, :self.keep_dims, ...] = sd[k]
1547
+ sd[k] = new_entry
1548
+
1549
+ missing, unexpected = self.load_state_dict(sd, strict=False) if not only_model else self.model.load_state_dict(
1550
+ sd, strict=False)
1551
+ print(f"Restored from {path} with {len(missing)} missing and {len(unexpected)} unexpected keys")
1552
+ if len(missing) > 0:
1553
+ print(f"Missing Keys: {missing}")
1554
+ if len(unexpected) > 0:
1555
+ print(f"Unexpected Keys: {unexpected}")
1556
+
1557
+ @torch.no_grad()
1558
+ def log_images(self, batch, N=8, n_row=4, sample=True, ddim_steps=200, ddim_eta=1., return_keys=None,
1559
+ quantize_denoised=True, inpaint=True, plot_denoise_rows=False, plot_progressive_rows=True,
1560
+ plot_diffusion_rows=True, unconditional_guidance_scale=1., unconditional_guidance_label=None,
1561
+ use_ema_scope=True,
1562
+ **kwargs):
1563
+ ema_scope = self.ema_scope if use_ema_scope else nullcontext
1564
+ use_ddim = ddim_steps is not None
1565
+
1566
+ log = dict()
1567
+ z, c, x, xrec, xc = self.get_input(batch, self.first_stage_key, bs=N, return_first_stage_outputs=True)
1568
+ c_cat, c = c["c_concat"][0], c["c_crossattn"][0]
1569
+ N = min(x.shape[0], N)
1570
+ n_row = min(x.shape[0], n_row)
1571
+ log["inputs"] = x
1572
+ log["reconstruction"] = xrec
1573
+ if self.model.conditioning_key is not None:
1574
+ if hasattr(self.cond_stage_model, "decode"):
1575
+ xc = self.cond_stage_model.decode(c)
1576
+ log["conditioning"] = xc
1577
+ elif self.cond_stage_key in ["caption", "txt"]:
1578
+ xc = log_txt_as_img((x.shape[2], x.shape[3]), batch[self.cond_stage_key], size=x.shape[2] // 25)
1579
+ log["conditioning"] = xc
1580
+ elif self.cond_stage_key in ['class_label', 'cls']:
1581
+ xc = log_txt_as_img((x.shape[2], x.shape[3]), batch["human_label"], size=x.shape[2] // 25)
1582
+ log['conditioning'] = xc
1583
+ elif isimage(xc):
1584
+ log["conditioning"] = xc
1585
+ if ismap(xc):
1586
+ log["original_conditioning"] = self.to_rgb(xc)
1587
+
1588
+ if not (self.c_concat_log_start is None and self.c_concat_log_end is None):
1589
+ log["c_concat_decoded"] = self.decode_first_stage(c_cat[:, self.c_concat_log_start:self.c_concat_log_end])
1590
+
1591
+ if plot_diffusion_rows:
1592
+ # get diffusion row
1593
+ diffusion_row = list()
1594
+ z_start = z[:n_row]
1595
+ for t in range(self.num_timesteps):
1596
+ if t % self.log_every_t == 0 or t == self.num_timesteps - 1:
1597
+ t = repeat(torch.tensor([t]), '1 -> b', b=n_row)
1598
+ t = t.to(self.device).long()
1599
+ noise = torch.randn_like(z_start)
1600
+ z_noisy = self.q_sample(x_start=z_start, t=t, noise=noise)
1601
+ diffusion_row.append(self.decode_first_stage(z_noisy))
1602
+
1603
+ diffusion_row = torch.stack(diffusion_row) # n_log_step, n_row, C, H, W
1604
+ diffusion_grid = rearrange(diffusion_row, 'n b c h w -> b n c h w')
1605
+ diffusion_grid = rearrange(diffusion_grid, 'b n c h w -> (b n) c h w')
1606
+ diffusion_grid = make_grid(diffusion_grid, nrow=diffusion_row.shape[0])
1607
+ log["diffusion_row"] = diffusion_grid
1608
+
1609
+ if sample:
1610
+ # get denoise row
1611
+ with ema_scope("Sampling"):
1612
+ samples, z_denoise_row = self.sample_log(cond={"c_concat": [c_cat], "c_crossattn": [c]},
1613
+ batch_size=N, ddim=use_ddim,
1614
+ ddim_steps=ddim_steps, eta=ddim_eta)
1615
+ # samples, z_denoise_row = self.sample(cond=c, batch_size=N, return_intermediates=True)
1616
+ x_samples = self.decode_first_stage(samples)
1617
+ log["samples"] = x_samples
1618
+ if plot_denoise_rows:
1619
+ denoise_grid = self._get_denoise_row_from_list(z_denoise_row)
1620
+ log["denoise_row"] = denoise_grid
1621
+
1622
+ if unconditional_guidance_scale > 1.0:
1623
+ uc_cross = self.get_unconditional_conditioning(N, unconditional_guidance_label)
1624
+ uc_cat = c_cat
1625
+ uc_full = {"c_concat": [uc_cat], "c_crossattn": [uc_cross]}
1626
+ with ema_scope("Sampling with classifier-free guidance"):
1627
+ samples_cfg, _ = self.sample_log(cond={"c_concat": [c_cat], "c_crossattn": [c]},
1628
+ batch_size=N, ddim=use_ddim,
1629
+ ddim_steps=ddim_steps, eta=ddim_eta,
1630
+ unconditional_guidance_scale=unconditional_guidance_scale,
1631
+ unconditional_conditioning=uc_full,
1632
+ )
1633
+ x_samples_cfg = self.decode_first_stage(samples_cfg)
1634
+ log[f"samples_cfg_scale_{unconditional_guidance_scale:.2f}"] = x_samples_cfg
1635
+
1636
+ return log
1637
+
1638
+
1639
+ class LatentInpaintDiffusion(LatentFinetuneDiffusion):
1640
+ """
1641
+ can either run as pure inpainting model (only concat mode) or with mixed conditionings,
1642
+ e.g. mask as concat and text via cross-attn.
1643
+ To disable finetuning mode, set finetune_keys to None
1644
+ """
1645
+
1646
+ def __init__(self,
1647
+ concat_keys=("mask", "masked_image"),
1648
+ masked_image_key="masked_image",
1649
+ *args, **kwargs
1650
+ ):
1651
+ super().__init__(concat_keys, *args, **kwargs)
1652
+ self.masked_image_key = masked_image_key
1653
+ assert self.masked_image_key in concat_keys
1654
+
1655
+ @torch.no_grad()
1656
+ def get_input(self, batch, k, cond_key=None, bs=None, return_first_stage_outputs=False):
1657
+ # note: restricted to non-trainable encoders currently
1658
+ assert not self.cond_stage_trainable, 'trainable cond stages not yet supported for inpainting'
1659
+ z, c, x, xrec, xc = super().get_input(batch, self.first_stage_key, return_first_stage_outputs=True,
1660
+ force_c_encode=True, return_original_cond=True, bs=bs)
1661
+
1662
+ assert exists(self.concat_keys)
1663
+ c_cat = list()
1664
+ for ck in self.concat_keys:
1665
+ cc = rearrange(batch[ck], 'b h w c -> b c h w').to(memory_format=torch.contiguous_format).float()
1666
+ if bs is not None:
1667
+ cc = cc[:bs]
1668
+ cc = cc.to(self.device)
1669
+ bchw = z.shape
1670
+ if ck != self.masked_image_key:
1671
+ cc = torch.nn.functional.interpolate(cc, size=bchw[-2:])
1672
+ else:
1673
+ cc = self.get_first_stage_encoding(self.encode_first_stage(cc))
1674
+ c_cat.append(cc)
1675
+ c_cat = torch.cat(c_cat, dim=1)
1676
+ all_conds = {"c_concat": [c_cat], "c_crossattn": [c]}
1677
+ if return_first_stage_outputs:
1678
+ return z, all_conds, x, xrec, xc
1679
+ return z, all_conds
1680
+
1681
+ @torch.no_grad()
1682
+ def log_images(self, *args, **kwargs):
1683
+ log = super(LatentInpaintDiffusion, self).log_images(*args, **kwargs)
1684
+ log["masked_image"] = rearrange(args[0]["masked_image"],
1685
+ 'b h w c -> b c h w').to(memory_format=torch.contiguous_format).float()
1686
+ return log
1687
+
1688
+
1689
+ class LatentDepth2ImageDiffusion(LatentFinetuneDiffusion):
1690
+ """
1691
+ condition on monocular depth estimation
1692
+ """
1693
+
1694
+ def __init__(self, depth_stage_config, concat_keys=("midas_in",), *args, **kwargs):
1695
+ super().__init__(concat_keys=concat_keys, *args, **kwargs)
1696
+ self.depth_model = instantiate_from_config(depth_stage_config)
1697
+ self.depth_stage_key = concat_keys[0]
1698
+
1699
+ @torch.no_grad()
1700
+ def get_input(self, batch, k, cond_key=None, bs=None, return_first_stage_outputs=False):
1701
+ # note: restricted to non-trainable encoders currently
1702
+ assert not self.cond_stage_trainable, 'trainable cond stages not yet supported for depth2img'
1703
+ z, c, x, xrec, xc = super().get_input(batch, self.first_stage_key, return_first_stage_outputs=True,
1704
+ force_c_encode=True, return_original_cond=True, bs=bs)
1705
+
1706
+ assert exists(self.concat_keys)
1707
+ assert len(self.concat_keys) == 1
1708
+ c_cat = list()
1709
+ for ck in self.concat_keys:
1710
+ cc = batch[ck]
1711
+ if bs is not None:
1712
+ cc = cc[:bs]
1713
+ cc = cc.to(self.device)
1714
+ cc = self.depth_model(cc)
1715
+ cc = torch.nn.functional.interpolate(
1716
+ cc,
1717
+ size=z.shape[2:],
1718
+ mode="bicubic",
1719
+ align_corners=False,
1720
+ )
1721
+
1722
+ depth_min, depth_max = torch.amin(cc, dim=[1, 2, 3], keepdim=True), torch.amax(cc, dim=[1, 2, 3],
1723
+ keepdim=True)
1724
+ cc = 2. * (cc - depth_min) / (depth_max - depth_min + 0.001) - 1.
1725
+ c_cat.append(cc)
1726
+ c_cat = torch.cat(c_cat, dim=1)
1727
+ all_conds = {"c_concat": [c_cat], "c_crossattn": [c]}
1728
+ if return_first_stage_outputs:
1729
+ return z, all_conds, x, xrec, xc
1730
+ return z, all_conds
1731
+
1732
+ @torch.no_grad()
1733
+ def log_images(self, *args, **kwargs):
1734
+ log = super().log_images(*args, **kwargs)
1735
+ depth = self.depth_model(args[0][self.depth_stage_key])
1736
+ depth_min, depth_max = torch.amin(depth, dim=[1, 2, 3], keepdim=True), \
1737
+ torch.amax(depth, dim=[1, 2, 3], keepdim=True)
1738
+ log["depth"] = 2. * (depth - depth_min) / (depth_max - depth_min) - 1.
1739
+ return log
1740
+
1741
+
1742
+ class LatentUpscaleFinetuneDiffusion(LatentFinetuneDiffusion):
1743
+ """
1744
+ condition on low-res image (and optionally on some spatial noise augmentation)
1745
+ """
1746
+ def __init__(self, concat_keys=("lr",), reshuffle_patch_size=None,
1747
+ low_scale_config=None, low_scale_key=None, *args, **kwargs):
1748
+ super().__init__(concat_keys=concat_keys, *args, **kwargs)
1749
+ self.reshuffle_patch_size = reshuffle_patch_size
1750
+ self.low_scale_model = None
1751
+ if low_scale_config is not None:
1752
+ print("Initializing a low-scale model")
1753
+ assert exists(low_scale_key)
1754
+ self.instantiate_low_stage(low_scale_config)
1755
+ self.low_scale_key = low_scale_key
1756
+
1757
+ def instantiate_low_stage(self, config):
1758
+ model = instantiate_from_config(config)
1759
+ self.low_scale_model = model.eval()
1760
+ self.low_scale_model.train = disabled_train
1761
+ for param in self.low_scale_model.parameters():
1762
+ param.requires_grad = False
1763
+
1764
+ @torch.no_grad()
1765
+ def get_input(self, batch, k, cond_key=None, bs=None, return_first_stage_outputs=False):
1766
+ # note: restricted to non-trainable encoders currently
1767
+ assert not self.cond_stage_trainable, 'trainable cond stages not yet supported for upscaling-ft'
1768
+ z, c, x, xrec, xc = super().get_input(batch, self.first_stage_key, return_first_stage_outputs=True,
1769
+ force_c_encode=True, return_original_cond=True, bs=bs)
1770
+
1771
+ assert exists(self.concat_keys)
1772
+ assert len(self.concat_keys) == 1
1773
+ # optionally make spatial noise_level here
1774
+ c_cat = list()
1775
+ noise_level = None
1776
+ for ck in self.concat_keys:
1777
+ cc = batch[ck]
1778
+ cc = rearrange(cc, 'b h w c -> b c h w')
1779
+ if exists(self.reshuffle_patch_size):
1780
+ assert isinstance(self.reshuffle_patch_size, int)
1781
+ cc = rearrange(cc, 'b c (p1 h) (p2 w) -> b (p1 p2 c) h w',
1782
+ p1=self.reshuffle_patch_size, p2=self.reshuffle_patch_size)
1783
+ if bs is not None:
1784
+ cc = cc[:bs]
1785
+ cc = cc.to(self.device)
1786
+ if exists(self.low_scale_model) and ck == self.low_scale_key:
1787
+ cc, noise_level = self.low_scale_model(cc)
1788
+ c_cat.append(cc)
1789
+ c_cat = torch.cat(c_cat, dim=1)
1790
+ if exists(noise_level):
1791
+ all_conds = {"c_concat": [c_cat], "c_crossattn": [c], "c_adm": noise_level}
1792
+ else:
1793
+ all_conds = {"c_concat": [c_cat], "c_crossattn": [c]}
1794
+ if return_first_stage_outputs:
1795
+ return z, all_conds, x, xrec, xc
1796
+ return z, all_conds
1797
+
1798
+ @torch.no_grad()
1799
+ def log_images(self, *args, **kwargs):
1800
+ log = super().log_images(*args, **kwargs)
1801
+ log["lr"] = rearrange(args[0]["lr"], 'b h w c -> b c h w')
1802
+ return log
1803
+
1804
+
1805
+ class ImageEmbeddingConditionedLatentDiffusion(LatentDiffusion):
1806
+ def __init__(self, embedder_config, embedding_key="jpg", embedding_dropout=0.5,
1807
+ freeze_embedder=True, noise_aug_config=None, *args, **kwargs):
1808
+ super().__init__(*args, **kwargs)
1809
+ self.embed_key = embedding_key
1810
+ self.embedding_dropout = embedding_dropout
1811
+ self._init_embedder(embedder_config, freeze_embedder)
1812
+ self._init_noise_aug(noise_aug_config)
1813
+
1814
+ def _init_embedder(self, config, freeze=True):
1815
+ embedder = instantiate_from_config(config)
1816
+ if freeze:
1817
+ self.embedder = embedder.eval()
1818
+ self.embedder.train = disabled_train
1819
+ for param in self.embedder.parameters():
1820
+ param.requires_grad = False
1821
+
1822
+ def _init_noise_aug(self, config):
1823
+ if config is not None:
1824
+ # use the KARLO schedule for noise augmentation on CLIP image embeddings
1825
+ noise_augmentor = instantiate_from_config(config)
1826
+ assert isinstance(noise_augmentor, nn.Module)
1827
+ noise_augmentor = noise_augmentor.eval()
1828
+ noise_augmentor.train = disabled_train
1829
+ self.noise_augmentor = noise_augmentor
1830
+ else:
1831
+ self.noise_augmentor = None
1832
+
1833
+ def get_input(self, batch, k, cond_key=None, bs=None, **kwargs):
1834
+ outputs = LatentDiffusion.get_input(self, batch, k, bs=bs, **kwargs)
1835
+ z, c = outputs[0], outputs[1]
1836
+ img = batch[self.embed_key][:bs]
1837
+ img = rearrange(img, 'b h w c -> b c h w')
1838
+ c_adm = self.embedder(img)
1839
+ if self.noise_augmentor is not None:
1840
+ c_adm, noise_level_emb = self.noise_augmentor(c_adm)
1841
+ # assume this gives embeddings of noise levels
1842
+ c_adm = torch.cat((c_adm, noise_level_emb), 1)
1843
+ if self.training:
1844
+ c_adm = torch.bernoulli((1. - self.embedding_dropout) * torch.ones(c_adm.shape[0],
1845
+ device=c_adm.device)[:, None]) * c_adm
1846
+ all_conds = {"c_crossattn": [c], "c_adm": c_adm}
1847
+ noutputs = [z, all_conds]
1848
+ noutputs.extend(outputs[2:])
1849
+ return noutputs
1850
+
1851
+ @torch.no_grad()
1852
+ def log_images(self, batch, N=8, n_row=4, **kwargs):
1853
+ log = dict()
1854
+ z, c, x, xrec, xc = self.get_input(batch, self.first_stage_key, bs=N, return_first_stage_outputs=True,
1855
+ return_original_cond=True)
1856
+ log["inputs"] = x
1857
+ log["reconstruction"] = xrec
1858
+ assert self.model.conditioning_key is not None
1859
+ assert self.cond_stage_key in ["caption", "txt"]
1860
+ xc = log_txt_as_img((x.shape[2], x.shape[3]), batch[self.cond_stage_key], size=x.shape[2] // 25)
1861
+ log["conditioning"] = xc
1862
+ uc = self.get_unconditional_conditioning(N, kwargs.get('unconditional_guidance_label', ''))
1863
+ unconditional_guidance_scale = kwargs.get('unconditional_guidance_scale', 5.)
1864
+
1865
+ uc_ = {"c_crossattn": [uc], "c_adm": c["c_adm"]}
1866
+ ema_scope = self.ema_scope if kwargs.get('use_ema_scope', True) else nullcontext
1867
+ with ema_scope(f"Sampling"):
1868
+ samples_cfg, _ = self.sample_log(cond=c, batch_size=N, ddim=True,
1869
+ ddim_steps=kwargs.get('ddim_steps', 50), eta=kwargs.get('ddim_eta', 0.),
1870
+ unconditional_guidance_scale=unconditional_guidance_scale,
1871
+ unconditional_conditioning=uc_, )
1872
+ x_samples_cfg = self.decode_first_stage(samples_cfg)
1873
+ log[f"samplescfg_scale_{unconditional_guidance_scale:.2f}"] = x_samples_cfg
1874
+ return log