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https://github.com/wassname/denoising-diffusion-pytorch.git
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from denoising_diffusion_pytorch.denoising_diffusion_pytorch import GaussianDiffusion, Unet, Trainer
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from denoising_diffusion_pytorch.denoising_diffusion_pytorch import GaussianDiffusion, Unet, Trainer
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from denoising_diffusion_pytorch.learned_gaussian_diffusion import LearnedGaussianDiffusion
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from denoising_diffusion_pytorch.learned_gaussian_diffusion import LearnedGaussianDiffusion
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from denoising_diffusion_pytorch.weighted_objective_gaussian_diffusion import WeightedObjectiveGaussianDiffusion
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@@ -603,34 +603,37 @@ class Trainer(object):
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self.scaler.load_state_dict(data['scaler'])
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self.scaler.load_state_dict(data['scaler'])
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def train(self):
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def train(self):
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while self.step < self.train_num_steps:
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with tqdm(initial = self.step, total = self.train_num_steps) as pbar:
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for i in range(self.gradient_accumulate_every):
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data = next(self.dl).cuda()
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with autocast(enabled = self.amp):
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while self.step < self.train_num_steps:
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loss = self.model(data)
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for i in range(self.gradient_accumulate_every):
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self.scaler.scale(loss / self.gradient_accumulate_every).backward()
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data = next(self.dl).cuda()
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print(f'{self.step}: {loss.item()}')
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with autocast(enabled = self.amp):
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loss = self.model(data)
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self.scaler.scale(loss / self.gradient_accumulate_every).backward()
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self.scaler.step(self.opt)
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pbar.set_description(f'loss: {loss.item():.4f}')
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self.scaler.update()
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self.opt.zero_grad()
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if self.step % self.update_ema_every == 0:
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self.scaler.step(self.opt)
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self.step_ema()
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self.scaler.update()
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self.opt.zero_grad()
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if self.step != 0 and self.step % self.save_and_sample_every == 0:
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if self.step % self.update_ema_every == 0:
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self.ema_model.eval()
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self.step_ema()
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milestone = self.step // self.save_and_sample_every
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if self.step != 0 and self.step % self.save_and_sample_every == 0:
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batches = num_to_groups(36, self.batch_size)
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self.ema_model.eval()
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all_images_list = list(map(lambda n: self.ema_model.sample(batch_size=n), batches))
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all_images = torch.cat(all_images_list, dim=0)
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all_images = unnormalize_to_zero_to_one(all_images)
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utils.save_image(all_images, str(self.results_folder / f'sample-{milestone}.png'), nrow = 6)
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self.save(milestone)
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self.step += 1
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milestone = self.step // self.save_and_sample_every
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batches = num_to_groups(36, self.batch_size)
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all_images_list = list(map(lambda n: self.ema_model.sample(batch_size=n), batches))
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all_images = torch.cat(all_images_list, dim=0)
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all_images = unnormalize_to_zero_to_one(all_images)
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utils.save_image(all_images, str(self.results_folder / f'sample-{milestone}.png'), nrow = 6)
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self.save(milestone)
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print('training completed')
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self.step += 1
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pbar.update(1)
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print('training complete')
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import torch
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from inspect import isfunction
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from torch import nn, einsum
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from einops import rearrange
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from denoising_diffusion_pytorch.denoising_diffusion_pytorch import GaussianDiffusion
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# helper functions
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def exists(x):
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return x is not None
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def default(val, d):
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if exists(val):
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return val
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return d() if isfunction(d) else d
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# some improvisation on my end
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# where i have the model learn to both predict noise and x0
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# and learn the weighted sum for each depending on time step
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class WeightedObjectiveGaussianDiffusion(GaussianDiffusion):
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def __init__(
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self,
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denoise_fn,
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*args,
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pred_noise_loss_weight = 0.1,
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pred_x_start_loss_weight = 0.1,
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**kwargs
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):
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super().__init__(denoise_fn, *args, **kwargs)
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channels = denoise_fn.channels
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assert denoise_fn.out_dim == (channels * 2 + 2), 'dimension out (out_dim) of unet must be twice the number of channels + 2 (for the softmax weighted sum) - for channels of 3, this should be (3 * 2) + 2 = 8'
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self.split_dims = (channels, channels, 2)
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self.pred_noise_loss_weight = pred_noise_loss_weight
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self.pred_x_start_loss_weight = pred_x_start_loss_weight
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def p_mean_variance(self, *, x, t, clip_denoised, model_output = None):
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model_output = self.denoise_fn(x, t)
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pred_noise, pred_x_start, weights = model_output.split(self.split_dims, dim = 1)
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normalized_weights = weights.softmax(dim = 1)
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x_start_from_noise = self.predict_start_from_noise(x, t = t, noise = pred_noise)
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x_starts = torch.stack((x_start_from_noise, pred_x_start), dim = 1)
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weighted_x_start = einsum('b j h w, b j c h w -> b c h w', normalized_weights, x_starts)
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if clip_denoised:
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weighted_x_start.clamp_(-1., 1.)
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model_mean, model_variance, model_log_variance = self.q_posterior(weighted_x_start, x, t)
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return model_mean, model_variance, model_log_variance
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def p_losses(self, x_start, t, noise = None, clip_denoised = False):
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noise = default(noise, lambda: torch.randn_like(x_start))
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x_t = self.q_sample(x_start = x_start, t = t, noise = noise)
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model_output = self.denoise_fn(x_t, t)
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pred_noise, pred_x_start, weights = model_output.split(self.split_dims, dim = 1)
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# get loss for predicted noise and x_start
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# with the loss weight given at initialization
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noise_loss = self.loss_fn(noise, pred_noise) * self.pred_noise_loss_weight
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x_start_loss = self.loss_fn(x_start, pred_x_start) * self.pred_x_start_loss_weight
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# calculate x_start from predicted noise
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# then do a weighted sum of the x_start prediction, weights also predicted by the model (softmax normalized)
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x_start_from_pred_noise = self.predict_start_from_noise(x_t, t, pred_noise)
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x_start_from_pred_noise = x_start_from_pred_noise.clamp(-2., 2.)
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weighted_x_start = einsum('b j h w, b j c h w -> b c h w', weights.softmax(dim = 1), torch.stack((x_start_from_pred_noise, pred_x_start), dim = 1))
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# main loss to x_start with the weighted one
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weighted_x_start_loss = self.loss_fn(x_start, weighted_x_start)
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return weighted_x_start_loss + x_start_loss + noise_loss
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@@ -3,7 +3,7 @@ from setuptools import setup, find_packages
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setup(
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setup(
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name = 'denoising-diffusion-pytorch',
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name = 'denoising-diffusion-pytorch',
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packages = find_packages(),
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packages = find_packages(),
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version = '0.15.0',
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version = '0.15.3',
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license='MIT',
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license='MIT',
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description = 'Denoising Diffusion Probabilistic Models - Pytorch',
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description = 'Denoising Diffusion Probabilistic Models - Pytorch',
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author = 'Phil Wang',
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author = 'Phil Wang',
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