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