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3 Commits
Author SHA1 Message Date
Phil Wang d4420248f1 tqdm auto instead 2022-06-29 19:48:49 -07:00
Phil Wang a536e5bee9 reorganize elucidating code 2022-06-29 08:49:38 -07:00
Phil Wang 1b85379d3a add clamping option to elucidated diffusion 2022-06-29 08:32:10 -07:00
3 changed files with 33 additions and 35 deletions
@@ -18,14 +18,9 @@ from PIL import Image
from einops import rearrange, reduce
from einops.layers.torch import Rearrange
from tqdm.auto import tqdm
from ema_pytorch import EMA
import sys
if 'ipykernel' in sys.modules:
from tqdm.notebook import tqdm
else:
from tqdm import tqdm
# helpers functions
def exists(x):
@@ -96,13 +96,30 @@ class ElucidatedDiffusion(nn.Module):
def c_noise(self, sigma):
return log(sigma) * 0.25
# noise distribution
# preconditioned network output
# equation (7) in the paper
def noise_distribution(self, batch_size):
return (self.P_mean + self.P_std * torch.randn((batch_size,), device = self.device)).exp()
def preconditioned_network_forward(self, noised_images, sigma, clamp = False):
batch, device = noised_images.shape[0], noised_images.device
def loss_weight(self, sigma):
return (sigma ** 2 + self.sigma_data ** 2) * (sigma * self.sigma_data) ** -2
if isinstance(sigma, float):
sigma = torch.full((batch,), sigma, device = device)
padded_sigma = rearrange(sigma, 'b -> b 1 1 1')
net_out = self.net(
self.c_in(padded_sigma) * noised_images,
self.c_noise(sigma)
)
out = self.c_skip(padded_sigma) * noised_images + self.c_out(padded_sigma) * net_out
if clamp:
out = out.clamp(-1., 1.)
return out
# sampling
# sample schedule
# equation (5) in the paper
@@ -119,28 +136,8 @@ class ElucidatedDiffusion(nn.Module):
sigmas = F.pad(sigmas, (0, 1), value = 0.) # last step is sigma value of 0.
return sigmas
# preconditioned network output
# equation (7) in the paper
def preconditioned_network_forward(self, noised_images, sigma):
batch, device = noised_images.shape[0], noised_images.device
if isinstance(sigma, float):
sigma = torch.full((batch,), sigma, device = device)
padded_sigma = rearrange(sigma, 'b -> b 1 1 1')
net_out = self.net(
self.c_in(padded_sigma) * noised_images,
self.c_noise(sigma)
)
return self.c_skip(padded_sigma) * noised_images + self.c_out(padded_sigma) * net_out
# sampling
@torch.no_grad()
def sample(self, batch_size = 16, num_sample_steps = None):
def sample(self, batch_size = 16, num_sample_steps = None, clamp = True):
num_sample_steps = default(num_sample_steps, self.num_sample_steps)
shape = (batch_size, self.channels, self.image_size, self.image_size)
@@ -173,7 +170,7 @@ class ElucidatedDiffusion(nn.Module):
sigma_hat = sigma + gamma * sigma
images_hat = images + sqrt(sigma_hat ** 2 - sigma ** 2) * eps
model_output = self.preconditioned_network_forward(images_hat, sigma_hat)
model_output = self.preconditioned_network_forward(images_hat, sigma_hat, clamp = clamp)
denoised_over_sigma = (images_hat - model_output) / sigma_hat
images_next = images_hat + (sigma_next - sigma_hat) * denoised_over_sigma
@@ -181,7 +178,7 @@ class ElucidatedDiffusion(nn.Module):
# second order correction, if not the last timestep
if sigma_next != 0:
model_output_next = self.preconditioned_network_forward(images_next, sigma_next)
model_output_next = self.preconditioned_network_forward(images_next, sigma_next, clamp = clamp)
denoised_prime_over_sigma = (images_next - model_output_next) / sigma_next
images_next = images_hat + 0.5 * (sigma_next - sigma_hat) * (denoised_over_sigma + denoised_prime_over_sigma)
@@ -192,6 +189,12 @@ class ElucidatedDiffusion(nn.Module):
# training
def loss_weight(self, sigma):
return (sigma ** 2 + self.sigma_data ** 2) * (sigma * self.sigma_data) ** -2
def noise_distribution(self, batch_size):
return (self.P_mean + self.P_std * torch.randn((batch_size,), device = self.device)).exp()
def forward(self, images):
batch_size, c, h, w, device, image_size, channels = *images.shape, images.device, self.image_size, self.channels
+1 -1
View File
@@ -3,7 +3,7 @@ from setuptools import setup, find_packages
setup(
name = 'denoising-diffusion-pytorch',
packages = find_packages(),
version = '0.23.2',
version = '0.23.4',
license='MIT',
description = 'Denoising Diffusion Probabilistic Models - Pytorch',
author = 'Phil Wang',