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