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7 changed files with 31 additions and 159 deletions

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@@ -14,16 +14,6 @@ Please join <a href="https://discord.gg/xBPBXfcFHd"><img alt="Join us on Discord
There was enough interest for a <a href="https://github.com/lucidrains/dalle2-jax">Jax version</a>. I will also eventually extend this to <a href="https://github.com/lucidrains/dalle2-video">text to video</a>, once the repository is in a good place.
## Status
- A research group has used the code in this repository to train a functional diffusion prior for their CLIP generations. Will share their work once they release their preprint. This, and <a href="https://github.com/crowsonkb">Katherine's</a> own experiments, validate OpenAI's finding that the extra prior increases variety of generations.
- Decoder is now verified working for unconditional generation on my experimental setup for Oxford flowers. 2 researchers have also confirmed Decoder is working for them.
<img src="./samples/oxford.png" width="600px" />
*ongoing at 21k steps*
## Install
```bash
@@ -824,8 +814,8 @@ clip = CLIP(
# mock data
text = torch.randint(0, 49408, (512, 256)).cuda()
images = torch.randn(512, 3, 256, 256).cuda()
text = torch.randint(0, 49408, (32, 256)).cuda()
images = torch.randn(32, 3, 256, 256).cuda()
# prior networks (with transformer)
@@ -858,7 +848,7 @@ diffusion_prior_trainer.update() # this will update the optimizer as well as th
# after much of the above three lines in a loop
# you can sample from the exponential moving average of the diffusion prior identically to how you do so for DiffusionPrior
image_embeds = diffusion_prior_trainer.sample(text, max_batch_size = 4) # (512, 512) - exponential moving averaged image embeddings
image_embeds = diffusion_prior_trainer.sample(text) # (4, 512) - exponential moving averaged image embeddings
```
## Bonus
@@ -871,7 +861,7 @@ ex.
```python
import torch
from dalle2_pytorch import Unet, Decoder, DecoderTrainer
from dalle2_pytorch import Unet, Decoder
# unet for the cascading ddpm
@@ -894,24 +884,20 @@ decoder = Decoder(
unconditional = True
).cuda()
# decoder trainer
decoder_trainer = DecoderTrainer(decoder)
# images (get a lot of this)
# mock images (get a lot of this)
images = torch.randn(1, 3, 512, 512).cuda()
# feed images into decoder
for i in (1, 2):
loss = decoder_trainer(images, unet_number = i)
decoder_trainer.update(unet_number = i)
loss = decoder(images, unet_number = i)
loss.backward()
# do the above for many many many many images
# do the above for many many many many steps
# then it will learn to generate images
images = decoder_trainer.sample(batch_size = 36, max_batch_size = 4) # (36, 3, 512, 512)
images = decoder.sample(batch_size = 2) # (2, 3, 512, 512)
```
## Dataloaders

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@@ -1697,8 +1697,7 @@ class Decoder(BaseGaussianDiffusion):
clip_adapter_overrides = dict(),
learned_variance = True,
vb_loss_weight = 0.001,
unconditional = False,
auto_normalize_img = True, # whether to take care of normalizing the image from [0, 1] to [-1, 1] and back automatically - you can turn this off if you want to pass in the [-1, 1] ranged image yourself from the dataloader
unconditional = False
):
super().__init__(
beta_schedule = beta_schedule,
@@ -1807,10 +1806,6 @@ class Decoder(BaseGaussianDiffusion):
self.clip_denoised = clip_denoised
self.clip_x_start = clip_x_start
# normalize and unnormalize image functions
self.normalize_img = normalize_neg_one_to_one if auto_normalize_img else identity
self.unnormalize_img = unnormalize_zero_to_one if auto_normalize_img else identity
def get_unet(self, unet_number):
assert 0 < unet_number <= len(self.unets)
index = unet_number - 1
@@ -1875,14 +1870,13 @@ class Decoder(BaseGaussianDiffusion):
return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise
@torch.no_grad()
def p_sample_loop(self, unet, shape, image_embed, predict_x_start = False, learned_variance = False, clip_denoised = True, lowres_cond_img = None, text_encodings = None, text_mask = None, cond_scale = 1, is_latent_diffusion = False):
def p_sample_loop(self, unet, shape, image_embed, predict_x_start = False, learned_variance = False, clip_denoised = True, lowres_cond_img = None, text_encodings = None, text_mask = None, cond_scale = 1):
device = self.betas.device
b = shape[0]
img = torch.randn(shape, device = device)
if not is_latent_diffusion:
lowres_cond_img = maybe(self.normalize_img)(lowres_cond_img)
lowres_cond_img = maybe(normalize_neg_one_to_one)(lowres_cond_img)
for i in tqdm(reversed(range(0, self.num_timesteps)), desc = 'sampling loop time step', total = self.num_timesteps):
img = self.p_sample(
@@ -1899,17 +1893,16 @@ class Decoder(BaseGaussianDiffusion):
clip_denoised = clip_denoised
)
unnormalize_img = self.unnormalize_img(img)
unnormalize_img = unnormalize_zero_to_one(img)
return unnormalize_img
def p_losses(self, unet, x_start, times, *, image_embed, lowres_cond_img = None, text_encodings = None, text_mask = None, predict_x_start = False, noise = None, learned_variance = False, clip_denoised = False, is_latent_diffusion = False):
def p_losses(self, unet, x_start, times, *, image_embed, lowres_cond_img = None, text_encodings = None, text_mask = None, predict_x_start = False, noise = None, learned_variance = False, clip_denoised = False):
noise = default(noise, lambda: torch.randn_like(x_start))
# normalize to [-1, 1]
if not is_latent_diffusion:
x_start = self.normalize_img(x_start)
lowres_cond_img = maybe(self.normalize_img)(lowres_cond_img)
x_start = normalize_neg_one_to_one(x_start)
lowres_cond_img = maybe(normalize_neg_one_to_one)(lowres_cond_img)
# get x_t
@@ -1987,7 +1980,7 @@ class Decoder(BaseGaussianDiffusion):
batch_size = image_embed.shape[0]
if exists(text) and not exists(text_encodings) and not self.unconditional:
assert exists(self.clip)
assert exist(self.clip)
_, text_encodings, text_mask = self.clip.embed_text(text)
assert not (self.condition_on_text_encodings and not exists(text_encodings)), 'text or text encodings must be passed into decoder if specified'
@@ -2023,8 +2016,7 @@ class Decoder(BaseGaussianDiffusion):
predict_x_start = predict_x_start,
learned_variance = learned_variance,
clip_denoised = not is_latent_diffusion,
lowres_cond_img = lowres_cond_img,
is_latent_diffusion = is_latent_diffusion
lowres_cond_img = lowres_cond_img
)
img = vae.decode(img)
@@ -2083,14 +2075,12 @@ class Decoder(BaseGaussianDiffusion):
image = aug(image)
lowres_cond_img = aug(lowres_cond_img, params = aug._params)
is_latent_diffusion = not isinstance(vae, NullVQGanVAE)
vae.eval()
with torch.no_grad():
image = vae.encode(image)
lowres_cond_img = maybe(vae.encode)(lowres_cond_img)
return self.p_losses(unet, image, times, image_embed = image_embed, text_encodings = text_encodings, text_mask = text_mask, lowres_cond_img = lowres_cond_img, predict_x_start = predict_x_start, learned_variance = learned_variance, is_latent_diffusion = is_latent_diffusion)
return self.p_losses(unet, image, times, image_embed = image_embed, text_encodings = text_encodings, text_mask = text_mask, lowres_cond_img = lowres_cond_img, predict_x_start = predict_x_start, learned_variance = learned_variance)
# main class

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@@ -1,59 +0,0 @@
from pathlib import Path
import torch
from torch.utils import data
from torchvision import transforms, utils
from PIL import Image
# helpers functions
def cycle(dl):
while True:
for data in dl:
yield data
# dataset and dataloader
class Dataset(data.Dataset):
def __init__(
self,
folder,
image_size,
exts = ['jpg', 'jpeg', 'png']
):
super().__init__()
self.folder = folder
self.image_size = image_size
self.paths = [p for ext in exts for p in Path(f'{folder}').glob(f'**/*.{ext}')]
self.transform = transforms.Compose([
transforms.Resize(image_size),
transforms.RandomHorizontalFlip(),
transforms.CenterCrop(image_size),
transforms.ToTensor()
])
def __len__(self):
return len(self.paths)
def __getitem__(self, index):
path = self.paths[index]
img = Image.open(path)
return self.transform(img)
def get_images_dataloader(
folder,
*,
batch_size,
image_size,
shuffle = True,
cycle_dl = True,
pin_memory = True
):
ds = Dataset(folder, image_size)
dl = data.DataLoader(ds, batch_size = batch_size, shuffle = shuffle, pin_memory = pin_memory)
if cycle_dl:
dl = cycle(dl)
return dl

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@@ -7,7 +7,7 @@ def separate_weight_decayable_params(params):
def get_optimizer(
params,
lr = 1e-4,
lr = 2e-5,
wd = 1e-2,
betas = (0.9, 0.999),
eps = 1e-8,

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@@ -47,14 +47,6 @@ def groupby_prefix_and_trim(prefix, d):
kwargs_without_prefix = dict(map(lambda x: (x[0][len(prefix):], x[1]), tuple(kwargs_with_prefix.items())))
return kwargs_without_prefix, kwargs
def num_to_groups(num, divisor):
groups = num // divisor
remainder = num % divisor
arr = [divisor] * groups
if remainder > 0:
arr.append(remainder)
return arr
# decorators
def cast_torch_tensor(fn):
@@ -187,8 +179,8 @@ class EMA(nn.Module):
self.online_model = model
self.ema_model = copy.deepcopy(model)
self.update_after_step = update_after_step # only start EMA after this step number, starting at 0
self.update_every = update_every
self.update_after_step = update_after_step // update_every # only start EMA after this step number, starting at 0
self.register_buffer('initted', torch.Tensor([False]))
self.register_buffer('step', torch.tensor([0.]))
@@ -197,21 +189,14 @@ class EMA(nn.Module):
device = self.initted.device
self.ema_model.to(device)
def copy_params_from_model_to_ema(self):
self.ema_model.state_dict(self.online_model.state_dict())
def update(self):
self.step += 1
if (self.step % self.update_every) != 0:
return
if self.step <= self.update_after_step:
self.copy_params_from_model_to_ema()
if self.step <= self.update_after_step or (self.step % self.update_every) != 0:
return
if not self.initted:
self.copy_params_from_model_to_ema()
self.ema_model.state_dict(self.online_model.state_dict())
self.initted.data.copy_(torch.Tensor([True]))
self.update_moving_average(self.ema_model, self.online_model)
@@ -235,16 +220,6 @@ class EMA(nn.Module):
# diffusion prior trainer
def prior_sample_in_chunks(fn):
@wraps(fn)
def inner(self, *args, max_batch_size = None, **kwargs):
if not exists(max_batch_size):
return fn(self, *args, **kwargs)
outputs = [fn(self, *chunked_args, **chunked_kwargs) for _, (chunked_args, chunked_kwargs) in split_args_and_kwargs(*args, split_size = max_batch_size, **kwargs)]
return torch.cat(outputs, dim = 0)
return inner
class DiffusionPriorTrainer(nn.Module):
def __init__(
self,
@@ -305,13 +280,11 @@ class DiffusionPriorTrainer(nn.Module):
@torch.no_grad()
@cast_torch_tensor
@prior_sample_in_chunks
def p_sample_loop(self, *args, **kwargs):
return self.ema_diffusion_prior.ema_model.p_sample_loop(*args, **kwargs)
@torch.no_grad()
@cast_torch_tensor
@prior_sample_in_chunks
def sample(self, *args, **kwargs):
return self.ema_diffusion_prior.ema_model.sample(*args, **kwargs)
@@ -342,31 +315,15 @@ class DiffusionPriorTrainer(nn.Module):
# decoder trainer
def decoder_sample_in_chunks(fn):
@wraps(fn)
def inner(self, *args, max_batch_size = None, **kwargs):
if not exists(max_batch_size):
return fn(self, *args, **kwargs)
if self.decoder.unconditional:
batch_size = kwargs.get('batch_size')
batch_sizes = num_to_groups(batch_size, max_batch_size)
outputs = [fn(self, *args, **{**kwargs, 'batch_size': sub_batch_size}) for sub_batch_size in batch_sizes]
else:
outputs = [fn(self, *chunked_args, **chunked_kwargs) for _, (chunked_args, chunked_kwargs) in split_args_and_kwargs(*args, split_size = max_batch_size, **kwargs)]
return torch.cat(outputs, dim = 0)
return inner
class DecoderTrainer(nn.Module):
def __init__(
self,
decoder,
use_ema = True,
lr = 1e-4,
lr = 2e-5,
wd = 1e-2,
eps = 1e-8,
max_grad_norm = 0.5,
max_grad_norm = None,
amp = False,
**kwargs
):
@@ -447,17 +404,15 @@ class DecoderTrainer(nn.Module):
@torch.no_grad()
@cast_torch_tensor
@decoder_sample_in_chunks
def sample(self, *args, **kwargs):
if kwargs.pop('use_non_ema', False) or not self.use_ema:
return self.decoder.sample(*args, **kwargs)
trainable_unets = self.decoder.unets
self.decoder.unets = self.unets # swap in exponential moving averaged unets for sampling
if self.use_ema:
trainable_unets = self.decoder.unets
self.decoder.unets = self.unets # swap in exponential moving averaged unets for sampling
output = self.decoder.sample(*args, **kwargs)
self.decoder.unets = trainable_unets # restore original training unets
if self.use_ema:
self.decoder.unets = trainable_unets # restore original training unets
# cast the ema_model unets back to original device
for ema in self.ema_unets:

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@@ -10,7 +10,7 @@ setup(
'dream = dalle2_pytorch.cli:dream'
],
},
version = '0.3.3',
version = '0.2.41',
license='MIT',
description = 'DALL-E 2',
author = 'Phil Wang',