""" wild mixture of https://github.com/lucidrains/denoising-diffusion-pytorch/blob/7706bdfc6f527f58d33f84b7b522e61e6e3164b3/denoising_diffusion_pytorch/denoising_diffusion_pytorch.py https://github.com/openai/improved-diffusion/blob/e94489283bb876ac1477d5dd7709bbbd2d9902ce/improved_diffusion/gaussian_diffusion.py https://github.com/CompVis/taming-transformers -- merci """ import itertools import logging from contextlib import contextmanager from functools import partial import numpy as np import pytorch_lightning as pl import torch from einops import rearrange, repeat from torch import nn from torchvision.utils import make_grid from tqdm import tqdm from imaginairy.modules.diffusion.util import ( extract_into_tensor, make_beta_schedule, noise_like, ) from imaginairy.modules.distributions import DiagonalGaussianDistribution from imaginairy.modules.ema import LitEma from imaginairy.utils import instantiate_from_config logger = logging.getLogger(__name__) __conditioning_keys__ = {"concat": "c_concat", "crossattn": "c_crossattn", "adm": "y"} def disabled_train(self): """ Overwrite model.train with this function to make sure train/eval mode does not change anymore. """ return self def uniform_on_device(r1, r2, shape, device): return (r1 - r2) * torch.rand(*shape, device=device) + r2 class DDPM(pl.LightningModule): # classic DDPM with Gaussian diffusion, in image space def __init__( self, unet_config, timesteps=1000, beta_schedule="linear", loss_type="l2", ckpt_path=None, ignore_keys=tuple(), load_only_unet=False, monitor="val/loss", use_ema=True, first_stage_key="image", image_size=256, channels=3, log_every_t=100, clip_denoised=True, linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3, given_betas=None, original_elbo_weight=0.0, v_posterior=0.0, # weight for choosing posterior variance as sigma = (1-v) * beta_tilde + v * beta l_simple_weight=1.0, conditioning_key=None, parameterization="eps", # all assuming fixed variance schedules scheduler_config=None, use_positional_encodings=False, learn_logvar=False, logvar_init=0.0, make_it_fit=False, ucg_training=None, reset_ema=False, reset_num_ema_updates=False, ): super().__init__() assert parameterization in [ "eps", "x0", "v", ], 'currently only supporting "eps" and "x0" and "v"' self.parameterization = parameterization # print( # f"{self.__class__.__name__}: Running in {self.parameterization}-prediction mode" # ) self.cond_stage_model = None self.clip_denoised = clip_denoised self.log_every_t = log_every_t self.first_stage_key = first_stage_key self.image_size = image_size # try conv? self.channels = channels self.use_positional_encodings = use_positional_encodings self.model = DiffusionWrapper(unet_config, conditioning_key) # count_params(self.model, verbose=True) self.use_ema = use_ema if self.use_ema: self.model_ema = LitEma(self.model) # print(f"Keeping EMAs of {len(list(self.model_ema.buffers()))}.") self.use_scheduler = scheduler_config is not None if self.use_scheduler: self.scheduler_config = scheduler_config self.v_posterior = v_posterior self.original_elbo_weight = original_elbo_weight self.l_simple_weight = l_simple_weight if monitor is not None: self.monitor = monitor self.make_it_fit = make_it_fit if reset_ema: assert ckpt_path is not None if ckpt_path is not None: self.init_from_ckpt( ckpt_path, ignore_keys=ignore_keys, only_model=load_only_unet ) if reset_ema: assert self.use_ema print( "Resetting ema to pure model weights. This is useful when restoring from an ema-only checkpoint." ) self.model_ema = LitEma(self.model) if reset_num_ema_updates: print( " +++++++++++ WARNING: RESETTING NUM_EMA UPDATES TO ZERO +++++++++++ " ) assert self.use_ema self.model_ema.reset_num_updates() self.register_schedule( given_betas=given_betas, beta_schedule=beta_schedule, timesteps=timesteps, linear_start=linear_start, linear_end=linear_end, cosine_s=cosine_s, ) self.loss_type = loss_type self.learn_logvar = learn_logvar self.logvar = torch.full(fill_value=logvar_init, size=(self.num_timesteps,)) if self.learn_logvar: self.logvar = nn.Parameter(self.logvar, requires_grad=True) self.ucg_training = ucg_training or {} if self.ucg_training: self.ucg_prng = np.random.RandomState() def register_schedule( self, given_betas=None, beta_schedule="linear", timesteps=1000, linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3, ): if given_betas is not None: betas = given_betas else: betas = make_beta_schedule( beta_schedule, timesteps, linear_start=linear_start, linear_end=linear_end, cosine_s=cosine_s, ) alphas = 1.0 - betas alphas_cumprod = np.cumprod(alphas, axis=0) alphas_cumprod_prev = np.append(1.0, alphas_cumprod[:-1]) (timesteps,) = betas.shape self.num_timesteps = int(timesteps) self.linear_start = linear_start self.linear_end = linear_end assert ( alphas_cumprod.shape[0] == self.num_timesteps ), "alphas have to be defined for each timestep" to_torch = partial(torch.tensor, dtype=torch.float32) self.register_buffer("betas", to_torch(betas)) self.register_buffer("alphas_cumprod", to_torch(alphas_cumprod)) self.register_buffer("alphas_cumprod_prev", to_torch(alphas_cumprod_prev)) # calculations for diffusion q(x_t | x_{t-1}) and others self.register_buffer("sqrt_alphas_cumprod", to_torch(np.sqrt(alphas_cumprod))) self.register_buffer( "sqrt_one_minus_alphas_cumprod", to_torch(np.sqrt(1.0 - alphas_cumprod)) ) self.register_buffer( "log_one_minus_alphas_cumprod", to_torch(np.log(1.0 - alphas_cumprod)) ) self.register_buffer( "sqrt_recip_alphas_cumprod", to_torch(np.sqrt(1.0 / alphas_cumprod)) ) self.register_buffer( "sqrt_recipm1_alphas_cumprod", to_torch(np.sqrt(1.0 / alphas_cumprod - 1)) ) # calculations for posterior q(x_{t-1} | x_t, x_0) posterior_variance = (1 - self.v_posterior) * betas * ( 1.0 - alphas_cumprod_prev ) / (1.0 - alphas_cumprod) + self.v_posterior * betas # above: equal to 1. / (1. / (1. - alpha_cumprod_tm1) + alpha_t / beta_t) self.register_buffer("posterior_variance", to_torch(posterior_variance)) # below: log calculation clipped because the posterior variance is 0 at the beginning of the diffusion chain self.register_buffer( "posterior_log_variance_clipped", to_torch(np.log(np.maximum(posterior_variance, 1e-20))), ) self.register_buffer( "posterior_mean_coef1", to_torch(betas * np.sqrt(alphas_cumprod_prev) / (1.0 - alphas_cumprod)), ) self.register_buffer( "posterior_mean_coef2", to_torch( (1.0 - alphas_cumprod_prev) * np.sqrt(alphas) / (1.0 - alphas_cumprod) ), ) if self.parameterization == "eps": lvlb_weights = self.betas**2 / ( 2 * self.posterior_variance * to_torch(alphas) * (1 - self.alphas_cumprod) ) elif self.parameterization == "x0": lvlb_weights = ( 0.5 * np.sqrt(torch.Tensor(alphas_cumprod)) / (2.0 * 1 - torch.Tensor(alphas_cumprod)) ) elif self.parameterization == "v": lvlb_weights = torch.ones_like( self.betas**2 / ( 2 * self.posterior_variance * to_torch(alphas) * (1 - self.alphas_cumprod) ) ) else: raise NotImplementedError("mu not supported") lvlb_weights[0] = lvlb_weights[1] self.register_buffer("lvlb_weights", lvlb_weights, persistent=False) assert not torch.isnan(self.lvlb_weights).all() @contextmanager def ema_scope(self, context=None): if self.use_ema: self.model_ema.store(self.model.parameters()) self.model_ema.copy_to(self.model) if context is not None: print(f"{context}: Switched to EMA weights") try: yield None finally: if self.use_ema: self.model_ema.restore(self.model.parameters()) if context is not None: print(f"{context}: Restored training weights") @torch.no_grad() def init_from_ckpt(self, path, ignore_keys=tuple(), only_model=False): sd = torch.load(path, map_location="cpu") if "state_dict" in list(sd.keys()): sd = sd["state_dict"] keys = list(sd.keys()) for k in keys: for ik in ignore_keys: if k.startswith(ik): print(f"Deleting key {k} from state_dict.") del sd[k] if self.make_it_fit: n_params = len( [ name for name, _ in itertools.chain( self.named_parameters(), self.named_buffers() ) ] ) for name, param in tqdm( itertools.chain(self.named_parameters(), self.named_buffers()), desc="Fitting old weights to new weights", total=n_params, ): if name not in sd: continue old_shape = sd[name].shape new_shape = param.shape assert len(old_shape) == len(new_shape) if len(new_shape) > 2: # we only modify first two axes assert new_shape[2:] == old_shape[2:] # assumes first axis corresponds to output dim if not new_shape == old_shape: new_param = param.clone() old_param = sd[name] if len(new_shape) == 1: for i in range(new_param.shape[0]): new_param[i] = old_param[i % old_shape[0]] elif len(new_shape) >= 2: for i in range(new_param.shape[0]): for j in range(new_param.shape[1]): new_param[i, j] = old_param[ i % old_shape[0], j % old_shape[1] ] n_used_old = torch.ones(old_shape[1]) for j in range(new_param.shape[1]): n_used_old[j % old_shape[1]] += 1 n_used_new = torch.zeros(new_shape[1]) for j in range(new_param.shape[1]): n_used_new[j] = n_used_old[j % old_shape[1]] n_used_new = n_used_new[None, :] while len(n_used_new.shape) < len(new_shape): n_used_new = n_used_new.unsqueeze(-1) new_param /= n_used_new sd[name] = new_param missing, unexpected = ( self.load_state_dict(sd, strict=False) if not only_model else self.model.load_state_dict(sd, strict=False) ) # print( # f"Restored from {path} with {len(missing)} missing and {len(unexpected)} unexpected keys" # ) # if len(missing) > 0: # print(f"Missing Keys:\n {missing}") # if len(unexpected) > 0: # print(f"\nUnexpected Keys:\n {unexpected}") def q_mean_variance(self, x_start, t): """ Get the distribution q(x_t | x_0). :param x_start: the [N x C x ...] tensor of noiseless inputs. :param t: the number of diffusion steps (minus 1). Here, 0 means one step. :return: A tuple (mean, variance, log_variance), all of x_start's shape. """ mean = extract_into_tensor(self.sqrt_alphas_cumprod, t, x_start.shape) * x_start variance = extract_into_tensor(1.0 - self.alphas_cumprod, t, x_start.shape) log_variance = extract_into_tensor( self.log_one_minus_alphas_cumprod, t, x_start.shape ) return mean, variance, log_variance def predict_start_from_noise(self, x_t, t, noise): return ( extract_into_tensor(self.sqrt_recip_alphas_cumprod, t, x_t.shape) * x_t - extract_into_tensor(self.sqrt_recipm1_alphas_cumprod, t, x_t.shape) * noise ) def predict_start_from_z_and_v(self, x_t, t, v): # self.register_buffer('sqrt_alphas_cumprod', to_torch(np.sqrt(alphas_cumprod))) # self.register_buffer('sqrt_one_minus_alphas_cumprod', to_torch(np.sqrt(1. - alphas_cumprod))) return ( extract_into_tensor(self.sqrt_alphas_cumprod, t, x_t.shape) * x_t - extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x_t.shape) * v ) def predict_eps_from_z_and_v(self, x_t, t, v): return ( extract_into_tensor(self.sqrt_alphas_cumprod, t, x_t.shape) * v + extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x_t.shape) * x_t ) def q_posterior(self, x_start, x_t, t): posterior_mean = ( extract_into_tensor(self.posterior_mean_coef1, t, x_t.shape) * x_start + extract_into_tensor(self.posterior_mean_coef2, t, x_t.shape) * x_t ) posterior_variance = extract_into_tensor(self.posterior_variance, t, x_t.shape) posterior_log_variance_clipped = extract_into_tensor( self.posterior_log_variance_clipped, t, x_t.shape ) return posterior_mean, posterior_variance, posterior_log_variance_clipped def p_mean_variance(self, x, t, clip_denoised: bool): model_out = self.model(x, t) if self.parameterization == "eps": x_recon = self.predict_start_from_noise(x, t=t, noise=model_out) elif self.parameterization == "x0": x_recon = model_out if clip_denoised: x_recon.clamp_(-1.0, 1.0) model_mean, posterior_variance, posterior_log_variance = self.q_posterior( x_start=x_recon, x_t=x, t=t ) return model_mean, posterior_variance, posterior_log_variance @torch.no_grad() def p_sample(self, x, t, clip_denoised=True, repeat_noise=False): b, *_, device = *x.shape, x.device model_mean, _, model_log_variance = self.p_mean_variance( x=x, t=t, clip_denoised=clip_denoised ) noise = noise_like(x.shape, device, repeat_noise) # no noise when t == 0 nonzero_mask = (1 - (t == 0).float()).reshape(b, *((1,) * (len(x.shape) - 1))) return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise @torch.no_grad() def p_sample_loop(self, shape, return_intermediates=False): device = self.betas.device b = shape[0] img = torch.randn(shape, device=device) intermediates = [img] for i in tqdm( reversed(range(0, self.num_timesteps)), desc="Sampling t", total=self.num_timesteps, ): img = self.p_sample( img, torch.full((b,), i, device=device, dtype=torch.long), clip_denoised=self.clip_denoised, ) if i % self.log_every_t == 0 or i == self.num_timesteps - 1: intermediates.append(img) if return_intermediates: return img, intermediates return img @torch.no_grad() def sample(self, batch_size=16, return_intermediates=False): image_size = self.image_size channels = self.channels return self.p_sample_loop( (batch_size, channels, image_size, image_size), return_intermediates=return_intermediates, ) def q_sample(self, x_start, t, noise=None): if noise is None: noise = torch.randn_like(x_start) return ( extract_into_tensor(self.sqrt_alphas_cumprod, t, x_start.shape) * x_start + extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x_start.shape) * noise ) def get_v(self, x, noise, t): return ( extract_into_tensor(self.sqrt_alphas_cumprod, t, x.shape) * noise - extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x.shape) * x ) def get_loss(self, pred, target, mean=True): if self.loss_type == "l1": loss = (target - pred).abs() if mean: loss = loss.mean() elif self.loss_type == "l2": if mean: loss = torch.nn.functional.mse_loss(target, pred) else: loss = torch.nn.functional.mse_loss(target, pred, reduction="none") else: raise NotImplementedError("unknown loss type '{loss_type}'") return loss def p_losses(self, x_start, t, noise=None): if noise is None: noise = torch.randn_like(x_start) x_noisy = self.q_sample(x_start=x_start, t=t, noise=noise) model_out = self.model(x_noisy, t) loss_dict = {} if self.parameterization == "eps": target = noise elif self.parameterization == "x0": target = x_start elif self.parameterization == "v": target = self.get_v(x_start, noise, t) else: raise NotImplementedError( f"Parameterization {self.parameterization} not yet supported" ) loss = self.get_loss(model_out, target, mean=False).mean(dim=[1, 2, 3]) log_prefix = "train" if self.training else "val" loss_dict.update({f"{log_prefix}/loss_simple": loss.mean()}) loss_simple = loss.mean() * self.l_simple_weight loss_vlb = (self.lvlb_weights[t] * loss).mean() loss_dict.update({f"{log_prefix}/loss_vlb": loss_vlb}) loss = loss_simple + self.original_elbo_weight * loss_vlb loss_dict.update({f"{log_prefix}/loss": loss}) return loss, loss_dict def forward(self, x, *args, **kwargs): # b, c, h, w, device, img_size, = *x.shape, x.device, self.image_size # assert h == img_size and w == img_size, f'height and width of image must be {img_size}' t = torch.randint( 0, self.num_timesteps, (x.shape[0],), device=self.device ).long() return self.p_losses(x, t, *args, **kwargs) def get_input(self, batch, k): x = batch[k] if len(x.shape) == 3: x = x[..., None] x = rearrange(x, "b h w c -> b c h w") x = x.to(memory_format=torch.contiguous_format).float() return x def shared_step(self, batch): x = self.get_input(batch, self.first_stage_key) loss, loss_dict = self(x) return loss, loss_dict def training_step(self, batch, batch_idx): for k in self.ucg_training: p = self.ucg_training[k]["p"] val = self.ucg_training[k]["val"] if val is None: val = "" for i in range(len(batch[k])): if self.ucg_prng.choice(2, p=[1 - p, p]): batch[k][i] = val loss, loss_dict = self.shared_step(batch) self.log_dict( loss_dict, prog_bar=True, logger=True, on_step=True, on_epoch=True ) self.log( "global_step", self.global_step, prog_bar=True, logger=True, on_step=True, on_epoch=False, ) if self.use_scheduler: lr = self.optimizers().param_groups[0]["lr"] self.log( "lr_abs", lr, prog_bar=True, logger=True, on_step=True, on_epoch=False ) return loss @torch.no_grad() def validation_step(self, batch, batch_idx): _, loss_dict_no_ema = self.shared_step(batch) with self.ema_scope(): _, loss_dict_ema = self.shared_step(batch) loss_dict_ema = {key + "_ema": loss_dict_ema[key] for key in loss_dict_ema} self.log_dict( loss_dict_no_ema, prog_bar=False, logger=True, on_step=False, on_epoch=True ) self.log_dict( loss_dict_ema, prog_bar=False, logger=True, on_step=False, on_epoch=True ) def on_train_batch_end(self, *args, **kwargs): if self.use_ema: self.model_ema(self.model) def _get_rows_from_list(self, samples): n_imgs_per_row = len(samples) denoise_grid = rearrange(samples, "n b c h w -> b n c h w") denoise_grid = rearrange(denoise_grid, "b n c h w -> (b n) c h w") denoise_grid = make_grid(denoise_grid, nrow=n_imgs_per_row) return denoise_grid @torch.no_grad() def log_images(self, batch, N=8, n_row=2, sample=True, return_keys=None, **kwargs): log = {} x = self.get_input(batch, self.first_stage_key) N = min(x.shape[0], N) n_row = min(x.shape[0], n_row) x = x.to(self.device)[:N] log["inputs"] = x # get diffusion row diffusion_row = [] x_start = x[:n_row] for t in range(self.num_timesteps): if t % self.log_every_t == 0 or t == self.num_timesteps - 1: t = repeat(torch.tensor([t]), "1 -> b", b=n_row) t = t.to(self.device).long() noise = torch.randn_like(x_start) x_noisy = self.q_sample(x_start=x_start, t=t, noise=noise) diffusion_row.append(x_noisy) log["diffusion_row"] = self._get_rows_from_list(diffusion_row) if sample: # get denoise row with self.ema_scope("Plotting"): samples, denoise_row = self.sample( batch_size=N, return_intermediates=True ) log["samples"] = samples log["denoise_row"] = self._get_rows_from_list(denoise_row) if return_keys: if np.intersect1d(list(log.keys()), return_keys).shape[0] == 0: return log return {key: log[key] for key in return_keys} return log def configure_optimizers(self): lr = self.learning_rate params = list(self.model.parameters()) if self.learn_logvar: params = params + [self.logvar] opt = torch.optim.AdamW(params, lr=lr) return opt class LatentDiffusion(DDPM): """main class""" def __init__( self, first_stage_config, cond_stage_config, num_timesteps_cond=None, cond_stage_key="image", cond_stage_trainable=False, concat_mode=True, cond_stage_forward=None, conditioning_key=None, scale_factor=1.0, scale_by_std=False, **kwargs, ): self.num_timesteps_cond = ( 1 if num_timesteps_cond is None else num_timesteps_cond ) self.scale_by_std = scale_by_std assert self.num_timesteps_cond <= kwargs["timesteps"] # for backwards compatibility after implementation of DiffusionWrapper if conditioning_key is None: conditioning_key = "concat" if concat_mode else "crossattn" if cond_stage_config == "__is_unconditional__": conditioning_key = None ckpt_path = kwargs.pop("ckpt_path", None) ignore_keys = kwargs.pop("ignore_keys", []) super().__init__(conditioning_key=conditioning_key, **kwargs) self.concat_mode = concat_mode self.cond_stage_trainable = cond_stage_trainable self.cond_stage_key = cond_stage_key try: self.num_downs = len(first_stage_config.params.ddconfig.ch_mult) - 1 except: # noqa logger.exception("Bad num downs?") self.num_downs = 0 if not scale_by_std: self.scale_factor = scale_factor else: self.register_buffer("scale_factor", torch.tensor(scale_factor)) self.instantiate_first_stage(first_stage_config) self.instantiate_cond_stage(cond_stage_config) self.cond_stage_forward = cond_stage_forward self.cond_ids = None self.clip_denoised = False self.bbox_tokenizer = None self.restarted_from_ckpt = False if ckpt_path is not None: self.init_from_ckpt(ckpt_path, ignore_keys) self.restarted_from_ckpt = True # store initial padding mode so we can switch to 'circular' # when we want tiled images for m in self.modules(): if isinstance(m, nn.Conv2d): m._initial_padding_mode = m.padding_mode def tile_mode(self, enabled): """For creating seamless tiles""" for m in self.modules(): if isinstance(m, nn.Conv2d): m.padding_mode = ( "circular" if enabled else m._initial_padding_mode # noqa ) def make_cond_schedule( self, ): self.cond_ids = torch.full( size=(self.num_timesteps,), fill_value=self.num_timesteps - 1, dtype=torch.long, ) ids = torch.round( torch.linspace(0, self.num_timesteps - 1, self.num_timesteps_cond) ).long() self.cond_ids[: self.num_timesteps_cond] = ids def register_schedule( self, given_betas=None, beta_schedule="linear", timesteps=1000, linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3, ): super().register_schedule( given_betas, beta_schedule, timesteps, linear_start, linear_end, cosine_s ) self.shorten_cond_schedule = self.num_timesteps_cond > 1 if self.shorten_cond_schedule: self.make_cond_schedule() def instantiate_first_stage(self, config): model = instantiate_from_config(config) self.first_stage_model = model.eval() self.first_stage_model.train = disabled_train for param in self.first_stage_model.parameters(): param.requires_grad = False def instantiate_cond_stage(self, config): if not self.cond_stage_trainable: if config == "__is_first_stage__": logger.debug("Using first stage also as cond stage.") self.cond_stage_model = self.first_stage_model elif config == "__is_unconditional__": logger.debug( f"Training {self.__class__.__name__} as an unconditional model." ) self.cond_stage_model = None # self.be_unconditional = True else: model = instantiate_from_config(config) self.cond_stage_model = model.eval() self.cond_stage_model.train = disabled_train for param in self.cond_stage_model.parameters(): param.requires_grad = False else: assert config != "__is_first_stage__" assert config != "__is_unconditional__" model = instantiate_from_config(config) self.cond_stage_model = model def _get_denoise_row_from_list(self, samples, desc=""): denoise_row = [] for zd in tqdm(samples, desc=desc): denoise_row.append(self.decode_first_stage(zd.to(self.device))) n_imgs_per_row = len(denoise_row) denoise_row = torch.stack(denoise_row) # n_log_step, n_row, C, H, W denoise_grid = rearrange(denoise_row, "n b c h w -> b n c h w") denoise_grid = rearrange(denoise_grid, "b n c h w -> (b n) c h w") denoise_grid = make_grid(denoise_grid, nrow=n_imgs_per_row) return denoise_grid def get_first_stage_encoding(self, encoder_posterior): if isinstance(encoder_posterior, DiagonalGaussianDistribution): z = encoder_posterior.sample() elif isinstance(encoder_posterior, torch.Tensor): z = encoder_posterior else: raise NotImplementedError( f"encoder_posterior of type '{type(encoder_posterior)}' not yet implemented" ) return self.scale_factor * z def get_learned_conditioning(self, c): if self.cond_stage_forward is None: if hasattr(self.cond_stage_model, "encode") and callable( self.cond_stage_model.encode ): c = self.cond_stage_model.encode(c) if isinstance(c, DiagonalGaussianDistribution): c = c.mode() else: c = self.cond_stage_model(c) else: assert hasattr(self.cond_stage_model, self.cond_stage_forward) c = getattr(self.cond_stage_model, self.cond_stage_forward)(c) return c def meshgrid(self, h, w): y = torch.arange(0, h).view(h, 1, 1).repeat(1, w, 1) x = torch.arange(0, w).view(1, w, 1).repeat(h, 1, 1) arr = torch.cat([y, x], dim=-1) return arr def delta_border(self, h, w): """ :param h: height :param w: width :return: normalized distance to image border, wtith min distance = 0 at border and max dist = 0.5 at image center """ lower_right_corner = torch.tensor([h - 1, w - 1]).view(1, 1, 2) arr = self.meshgrid(h, w) / lower_right_corner dist_left_up = torch.min(arr, dim=-1, keepdims=True)[0] dist_right_down = torch.min(1 - arr, dim=-1, keepdims=True)[0] edge_dist = torch.min( torch.cat([dist_left_up, dist_right_down], dim=-1), dim=-1 )[0] return edge_dist def get_weighting(self, h, w, Ly, Lx, device): weighting = self.delta_border(h, w) weighting = torch.clip( weighting, self.split_input_params["clip_min_weight"], self.split_input_params["clip_max_weight"], ) weighting = weighting.view(1, h * w, 1).repeat(1, 1, Ly * Lx).to(device) if self.split_input_params["tie_braker"]: L_weighting = self.delta_border(Ly, Lx) L_weighting = torch.clip( L_weighting, self.split_input_params["clip_min_tie_weight"], self.split_input_params["clip_max_tie_weight"], ) L_weighting = L_weighting.view(1, 1, Ly * Lx).to(device) weighting = weighting * L_weighting return weighting def get_fold_unfold( self, x, kernel_size, stride, uf=1, df=1 ): # todo load once not every time, shorten code """ :param x: img of size (bs, c, h, w) :return: n img crops of size (n, bs, c, kernel_size[0], kernel_size[1]) """ bs, nc, h, w = x.shape # noqa # number of crops in image Ly = (h - kernel_size[0]) // stride[0] + 1 Lx = (w - kernel_size[1]) // stride[1] + 1 if uf == 1 and df == 1: fold_params = dict( kernel_size=kernel_size, dilation=1, padding=0, stride=stride ) unfold = torch.nn.Unfold(**fold_params) fold = torch.nn.Fold(output_size=x.shape[2:], **fold_params) weighting = self.get_weighting( kernel_size[0], kernel_size[1], Ly, Lx, x.device ).to(x.dtype) normalization = fold(weighting).view(1, 1, h, w) # normalizes the overlap weighting = weighting.view((1, 1, kernel_size[0], kernel_size[1], Ly * Lx)) elif uf > 1 and df == 1: fold_params = dict( kernel_size=kernel_size, dilation=1, padding=0, stride=stride ) unfold = torch.nn.Unfold(**fold_params) fold_params2 = dict( kernel_size=(kernel_size[0] * uf, kernel_size[0] * uf), dilation=1, padding=0, stride=(stride[0] * uf, stride[1] * uf), ) fold = torch.nn.Fold( output_size=(x.shape[2] * uf, x.shape[3] * uf), **fold_params2 ) weighting = self.get_weighting( kernel_size[0] * uf, kernel_size[1] * uf, Ly, Lx, x.device ).to(x.dtype) normalization = fold(weighting).view( 1, 1, h * uf, w * uf ) # normalizes the overlap weighting = weighting.view( (1, 1, kernel_size[0] * uf, kernel_size[1] * uf, Ly * Lx) ) elif df > 1 and uf == 1: fold_params = dict( kernel_size=kernel_size, dilation=1, padding=0, stride=stride ) unfold = torch.nn.Unfold(**fold_params) fold_params2 = dict( kernel_size=(kernel_size[0] // df, kernel_size[0] // df), dilation=1, padding=0, stride=(stride[0] // df, stride[1] // df), ) fold = torch.nn.Fold( output_size=(x.shape[2] // df, x.shape[3] // df), **fold_params2 ) weighting = self.get_weighting( kernel_size[0] // df, kernel_size[1] // df, Ly, Lx, x.device ).to(x.dtype) normalization = fold(weighting).view( 1, 1, h // df, w // df ) # normalizes the overlap weighting = weighting.view( (1, 1, kernel_size[0] // df, kernel_size[1] // df, Ly * Lx) ) else: raise NotImplementedError return fold, unfold, normalization, weighting @torch.no_grad() def get_input( self, batch, k, return_first_stage_outputs=False, force_c_encode=False, cond_key=None, return_original_cond=False, bs=None, ): x = super().get_input(batch, k) if bs is not None: x = x[:bs] x = x.to(self.device) encoder_posterior = self.encode_first_stage(x) z = self.get_first_stage_encoding(encoder_posterior).detach() if self.model.conditioning_key is not None: if cond_key is None: cond_key = self.cond_stage_key if cond_key != self.first_stage_key: if cond_key in ["caption", "coordinates_bbox"]: xc = batch[cond_key] elif cond_key == "class_label": xc = batch else: xc = super().get_input(batch, cond_key).to(self.device) else: xc = x if not self.cond_stage_trainable or force_c_encode: if isinstance(xc, (dict, list)): # import pudb; pudb.set_trace() c = self.get_learned_conditioning(xc) else: c = self.get_learned_conditioning(xc.to(self.device)) else: c = xc if bs is not None: c = c[:bs] if self.use_positional_encodings: pos_x, pos_y = self.compute_latent_shifts(batch) ckey = __conditioning_keys__[self.model.conditioning_key] c = {ckey: c, "pos_x": pos_x, "pos_y": pos_y} else: c = None xc = None if self.use_positional_encodings: pos_x, pos_y = self.compute_latent_shifts(batch) c = {"pos_x": pos_x, "pos_y": pos_y} out = [z, c] if return_first_stage_outputs: xrec = self.decode_first_stage(z) out.extend([x, xrec]) if return_original_cond: out.append(xc) return out @torch.no_grad() def decode_first_stage(self, z, predict_cids=False): if predict_cids: if z.dim() == 4: z = torch.argmax(z.exp(), dim=1).long() z = self.first_stage_model.quantize.get_codebook_entry(z, shape=None) z = rearrange(z, "b h w c -> b c h w").contiguous() z = 1.0 / self.scale_factor * z return self.first_stage_model.decode(z) @torch.no_grad() def encode_first_stage(self, x): if ( hasattr(self, "split_input_params") and self.split_input_params["patch_distributed_vq"] ): ks = self.split_input_params["ks"] # eg. (128, 128) stride = self.split_input_params["stride"] # eg. (64, 64) df = self.split_input_params["vqf"] self.split_input_params["original_image_size"] = x.shape[-2:] bs, nc, h, w = x.shape # noqa if ks[0] > h or ks[1] > w: ks = (min(ks[0], h), min(ks[1], w)) logger.info("reducing Kernel") if stride[0] > h or stride[1] > w: stride = (min(stride[0], h), min(stride[1], w)) logger.info("reducing stride") fold, unfold, normalization, weighting = self.get_fold_unfold( x, ks, stride, df=df ) z = unfold(x) # (bn, nc * prod(**ks), L) # Reshape to img shape z = z.view( (z.shape[0], -1, ks[0], ks[1], z.shape[-1]) ) # (bn, nc, ks[0], ks[1], L ) output_list = [ self.first_stage_model.encode(z[:, :, :, :, i]) for i in range(z.shape[-1]) ] o = torch.stack(output_list, axis=-1) o = o * weighting # Reverse reshape to img shape o = o.view((o.shape[0], -1, o.shape[-1])) # (bn, nc * ks[0] * ks[1], L) # stitch crops together decoded = fold(o) decoded = decoded / normalization return decoded return self.first_stage_model.encode(x) def apply_model(self, x_noisy, t, cond, return_ids=False): if isinstance(cond, dict): # hybrid case, cond is expected to be a dict pass else: if not isinstance(cond, list): cond = [cond] key = ( "c_concat" if self.model.conditioning_key == "concat" else "c_crossattn" ) cond = {key: cond} if hasattr(self, "split_input_params"): assert len(cond) == 1 # todo can only deal with one conditioning atm assert not return_ids ks = self.split_input_params["ks"] # eg. (128, 128) stride = self.split_input_params["stride"] # eg. (64, 64) h, w = x_noisy.shape[-2:] # noqa fold, unfold, normalization, weighting = self.get_fold_unfold( x_noisy, ks, stride ) z = unfold(x_noisy) # (bn, nc * prod(**ks), L) # Reshape to img shape z = z.view( (z.shape[0], -1, ks[0], ks[1], z.shape[-1]) ) # (bn, nc, ks[0], ks[1], L ) z_list = [z[:, :, :, :, i] for i in range(z.shape[-1])] if ( self.cond_stage_key in ["image", "LR_image", "segmentation", "bbox_img"] and self.model.conditioning_key ): # todo check for completeness c_key = next(iter(cond.keys())) # get key c = next(iter(cond.values())) # get value assert len(c) == 1 # todo extend to list with more than one elem c = c[0] # get element c = unfold(c) c = c.view( (c.shape[0], -1, ks[0], ks[1], c.shape[-1]) ) # (bn, nc, ks[0], ks[1], L ) cond_list = [{c_key: [c[:, :, :, :, i]]} for i in range(c.shape[-1])] elif self.cond_stage_key == "coordinates_bbox": assert ( "original_image_size" in self.split_input_params ), "BoudingBoxRescaling is missing original_image_size" # assuming padding of unfold is always 0 and its dilation is always 1 n_patches_per_row = int((w - ks[0]) / stride[0] + 1) full_img_h, full_img_w = self.split_input_params["original_image_size"] # as we are operating on latents, we need the factor from the original image size to the # spatial latent size to properly rescale the crops for regenerating the bbox annotations num_downs = self.first_stage_model.encoder.num_resolutions - 1 rescale_latent = 2 ** (num_downs) # get top left positions of patches as conforming for the bbbox tokenizer, therefore we # need to rescale the tl patch coordinates to be in between (0,1) tl_patch_coordinates = [ ( rescale_latent * stride[0] * (patch_nr % n_patches_per_row) / full_img_w, rescale_latent * stride[1] * (patch_nr // n_patches_per_row) / full_img_h, ) for patch_nr in range(z.shape[-1]) ] # patch_limits are tl_coord, width and height coordinates as (x_tl, y_tl, h, w) patch_limits = [ ( x_tl, y_tl, rescale_latent * ks[0] / full_img_w, rescale_latent * ks[1] / full_img_h, ) for x_tl, y_tl in tl_patch_coordinates ] # patch_values = [(np.arange(x_tl,min(x_tl+ks, 1.)),np.arange(y_tl,min(y_tl+ks, 1.))) for x_tl, y_tl in tl_patch_coordinates] # tokenize crop coordinates for the bounding boxes of the respective patches patch_limits_tknzd = [ torch.LongTensor(self.bbox_tokenizer._crop_encoder(bbox))[ # noqa None ].to( # noqa self.device ) for bbox in patch_limits ] # list of length l with tensors of shape (1, 2) # cut tknzd crop position from conditioning assert isinstance(cond, dict), "cond must be dict to be fed into model" cut_cond = cond["c_crossattn"][0][..., :-2].to(self.device) adapted_cond = torch.stack( [torch.cat([cut_cond, p], dim=1) for p in patch_limits_tknzd] ) adapted_cond = rearrange(adapted_cond, "l b n -> (l b) n") adapted_cond = self.get_learned_conditioning(adapted_cond) adapted_cond = rearrange( adapted_cond, "(l b) n d -> l b n d", l=z.shape[-1] ) cond_list = [{"c_crossattn": [e]} for e in adapted_cond] else: cond_list = [ cond for i in range(z.shape[-1]) ] # Todo make this more efficient # apply model by loop over crops output_list = [ self.model(z_list[i], t, **cond_list[i]) for i in range(z.shape[-1]) ] assert not isinstance( output_list[0], tuple ) # todo can't deal with multiple model outputs check this never happens o = torch.stack(output_list, axis=-1) o = o * weighting # Reverse reshape to img shape o = o.view((o.shape[0], -1, o.shape[-1])) # (bn, nc * ks[0] * ks[1], L) # stitch crops together x_recon = fold(o) / normalization else: x_recon = self.model(x_noisy, t, **cond) if isinstance(x_recon, tuple) and not return_ids: return x_recon[0] return x_recon def p_mean_variance( self, x, c, t, clip_denoised: bool, return_codebook_ids=False, quantize_denoised=False, return_x0=False, score_corrector=None, corrector_kwargs=None, ): t_in = t model_out = self.apply_model(x, t_in, c, return_ids=return_codebook_ids) if score_corrector is not None: assert self.parameterization == "eps" model_out = score_corrector.modify_score( self, model_out, x, t, c, **corrector_kwargs ) if return_codebook_ids: model_out, logits = model_out if self.parameterization == "eps": x_recon = self.predict_start_from_noise(x, t=t, noise=model_out) elif self.parameterization == "x0": x_recon = model_out else: raise NotImplementedError() if clip_denoised: x_recon.clamp_(-1.0, 1.0) if quantize_denoised: x_recon, _, _ = self.first_stage_model.quantize(x_recon) model_mean, posterior_variance, posterior_log_variance = self.q_posterior( x_start=x_recon, x_t=x, t=t ) if return_codebook_ids: return model_mean, posterior_variance, posterior_log_variance, logits if return_x0: return model_mean, posterior_variance, posterior_log_variance, x_recon return model_mean, posterior_variance, posterior_log_variance @torch.no_grad() def p_sample( # noqa self, x, c, t, clip_denoised=False, repeat_noise=False, return_codebook_ids=False, quantize_denoised=False, return_x0=False, temperature=1.0, noise_dropout=0.0, score_corrector=None, corrector_kwargs=None, ): b, *_, device = *x.shape, x.device outputs = self.p_mean_variance( x=x, c=c, t=t, clip_denoised=clip_denoised, return_codebook_ids=return_codebook_ids, quantize_denoised=quantize_denoised, return_x0=return_x0, score_corrector=score_corrector, corrector_kwargs=corrector_kwargs, ) if return_x0: model_mean, _, model_log_variance, x0 = outputs else: model_mean, _, model_log_variance = outputs noise = noise_like(x.shape, device, repeat_noise) * temperature if noise_dropout > 0.0: noise = torch.nn.functional.dropout(noise, p=noise_dropout) # no noise when t == 0 nonzero_mask = (1 - (t == 0).float()).reshape(b, *((1,) * (len(x.shape) - 1))) if return_x0: return ( model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise, x0, ) return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise def q_sample(self, x_start, t, noise=None): if noise is None: noise = torch.randn_like(x_start, device="cpu").to(x_start.device) return ( extract_into_tensor(self.sqrt_alphas_cumprod, t, x_start.shape) * x_start + extract_into_tensor(self.sqrt_one_minus_alphas_cumprod, t, x_start.shape) * noise ) class DiffusionWrapper(pl.LightningModule): def __init__(self, diff_model_config, conditioning_key): super().__init__() self.diffusion_model = instantiate_from_config(diff_model_config) self.conditioning_key = conditioning_key assert self.conditioning_key in [None, "concat", "crossattn", "hybrid", "adm"] def forward(self, x, t, c_concat: list = None, c_crossattn: list = None): if self.conditioning_key is None: out = self.diffusion_model(x, t) elif self.conditioning_key == "concat": xc = torch.cat([x] + c_concat, dim=1) out = self.diffusion_model(xc, t) elif self.conditioning_key == "crossattn": cc = torch.cat(c_crossattn, 1) out = self.diffusion_model(x, t, context=cc) elif self.conditioning_key == "hybrid": xc = torch.cat([x] + c_concat, dim=1) cc = torch.cat(c_crossattn, 1) out = self.diffusion_model(xc, t, context=cc) elif self.conditioning_key == "adm": cc = c_crossattn[0] out = self.diffusion_model(x, t, y=cc) else: raise NotImplementedError() return out class LatentInpaintDiffusion(LatentDiffusion): def __init__( # noqa self, concat_keys=("mask", "masked_image"), masked_image_key="masked_image", finetune_keys=None, # noqa *args, **kwargs, ): super().__init__(*args, **kwargs) self.masked_image_key = masked_image_key assert self.masked_image_key in concat_keys self.concat_keys = concat_keys @torch.no_grad() def get_input( self, batch, k, cond_key=None, bs=None, return_first_stage_outputs=False ): # note: restricted to non-trainable encoders currently assert ( not self.cond_stage_trainable ), "trainable cond stages not yet supported for inpainting" z, c, x, xrec, xc = super().get_input( batch, self.first_stage_key, return_first_stage_outputs=True, force_c_encode=True, return_original_cond=True, bs=bs, ) assert self.concat_keys is not None c_cat = [] for ck in self.concat_keys: cc = ( rearrange(batch[ck], "b h w c -> b c h w") .to(memory_format=torch.contiguous_format) .float() ) if bs is not None: cc = cc[:bs] cc = cc.to(self.device) bchw = z.shape if ck != self.masked_image_key: cc = torch.nn.functional.interpolate(cc, size=bchw[-2:]) else: cc = self.get_first_stage_encoding(self.encode_first_stage(cc)) c_cat.append(cc) c_cat = torch.cat(c_cat, dim=1) all_conds = {"c_concat": [c_cat], "c_crossattn": [c]} if return_first_stage_outputs: return z, all_conds, x, xrec, xc return z, all_conds