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Author SHA1 Message Date
Phil Wang
39d3659ad9 now completely OpenAI CLIP compatible for training 2022-04-29 11:26:24 -07:00
12 changed files with 165 additions and 1450 deletions

227
README.md
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@@ -10,7 +10,7 @@ The main novelty seems to be an extra layer of indirection with the prior networ
This model is SOTA for text-to-image for now.
Please join <a href="https://discord.gg/xBPBXfcFHd"><img alt="Join us on Discord" src="https://img.shields.io/discord/823813159592001537?color=5865F2&logo=discord&logoColor=white"></a> if you are interested in helping out with the replication with the <a href="https://laion.ai/">LAION</a> community | <a href="https://www.youtube.com/watch?v=AIOE1l1W0Tw">Yannic Interview</a>
Please join <a href="https://discord.gg/xBPBXfcFHd"><img alt="Join us on Discord" src="https://img.shields.io/discord/823813159592001537?color=5865F2&logo=discord&logoColor=white"></a> if you are interested in helping out with the replication
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.
@@ -47,7 +47,7 @@ clip = CLIP(
use_all_token_embeds = True, # whether to use fine-grained contrastive learning (FILIP)
decoupled_contrastive_learning = True, # use decoupled contrastive learning (DCL) objective function, removing positive pairs from the denominator of the InfoNCE loss (CLOOB + DCL)
extra_latent_projection = True, # whether to use separate projections for text-to-image vs image-to-text comparisons (CLOOB)
use_visual_ssl = True, # whether to do self supervised learning on images
use_visual_ssl = True, # whether to do self supervised learning on iages
visual_ssl_type = 'simclr', # can be either 'simclr' or 'simsiam', depending on using DeCLIP or SLIP
use_mlm = False, # use masked language learning (MLM) on text (DeCLIP)
text_ssl_loss_weight = 0.05, # weight for text MLM loss
@@ -110,8 +110,7 @@ decoder = Decoder(
unet = unet,
clip = clip,
timesteps = 100,
image_cond_drop_prob = 0.1,
text_cond_drop_prob = 0.5
cond_drop_prob = 0.2
).cuda()
# mock images (get a lot of this)
@@ -230,8 +229,7 @@ decoder = Decoder(
unet = (unet1, unet2), # insert both unets in order of low resolution to highest resolution (you can have as many stages as you want here)
image_sizes = (256, 512), # resolutions, 256 for first unet, 512 for second. these must be unique and in ascending order (matches with the unets passed in)
timesteps = 1000,
image_cond_drop_prob = 0.1,
text_cond_drop_prob = 0.5
cond_drop_prob = 0.2
).cuda()
# mock images (get a lot of this)
@@ -350,8 +348,7 @@ decoder = Decoder(
image_sizes = (128, 256),
clip = clip,
timesteps = 100,
image_cond_drop_prob = 0.1,
text_cond_drop_prob = 0.5,
cond_drop_prob = 0.2,
condition_on_text_encodings = False # set this to True if you wish to condition on text during training and sampling
).cuda()
@@ -433,8 +430,8 @@ images = torch.randn(4, 3, 256, 256).cuda()
# precompute the text and image embeddings
# here using the diffusion prior class, but could be done with CLIP alone
clip_image_embeds = diffusion_prior.clip.embed_image(images).image_embed
clip_text_embeds = diffusion_prior.clip.embed_text(text).text_embed
clip_image_embeds = diffusion_prior.get_image_embed(images)
clip_text_embeds = diffusion_prior.get_text_cond(text).get('text_embed')
# feed text and images into diffusion prior network
@@ -502,7 +499,9 @@ loss.backward()
Although there is the possibility they are using an unreleased, more powerful CLIP, you can use one of the released ones, if you do not wish to train your own CLIP from scratch. This will also allow the community to more quickly validate the conclusions of the paper.
To use a pretrained OpenAI CLIP, simply import `OpenAIClipAdapter` and pass it into the `DiffusionPrior` or `Decoder` like so
First you'll need to install <a href="https://github.com/openai/CLIP#usage">the prerequisites</a>
Then to use a pretrained OpenAI CLIP, simply import `OpenAIClipAdapter` and pass it into the `DiffusionPrior` or `Decoder` like so
```python
import torch
@@ -561,8 +560,7 @@ decoder = Decoder(
image_sizes = (128, 256),
clip = clip,
timesteps = 100,
image_cond_drop_prob = 0.1,
text_cond_drop_prob = 0.5,
cond_drop_prob = 0.2,
condition_on_text_encodings = False # set this to True if you wish to condition on text during training and sampling
).cuda()
@@ -620,7 +618,7 @@ clip = CLIP(
# 3 unets for the decoder (a la cascading DDPM)
# first two unets are doing latent diffusion
# vqgan-vae must be trained beforehand
# vqgan-vae must be trained before hand
vae1 = VQGanVAE(
dim = 32,
@@ -673,8 +671,7 @@ decoder = Decoder(
unet = (unet1, unet2, unet3), # insert unets in order of low resolution to highest resolution (you can have as many stages as you want here)
image_sizes = (256, 512, 1024), # resolutions, 256 for first unet, 512 for second, 1024 for third
timesteps = 100,
image_cond_drop_prob = 0.1,
text_cond_drop_prob = 0.5
cond_drop_prob = 0.2
).cuda()
# mock images (get a lot of this)
@@ -708,164 +705,7 @@ images = decoder.sample(mock_image_embed) # (1, 3, 1024, 1024)
## Training wrapper (wip)
### Decoder Training
Training the `Decoder` may be confusing, as one needs to keep track of an optimizer for each of the `Unet`(s) separately. Each `Unet` will also need its own corresponding exponential moving average. The `DecoderTrainer` hopes to make this simple, as shown below
```python
import torch
from dalle2_pytorch import DALLE2, Unet, Decoder, CLIP, DecoderTrainer
clip = CLIP(
dim_text = 512,
dim_image = 512,
dim_latent = 512,
num_text_tokens = 49408,
text_enc_depth = 6,
text_seq_len = 256,
text_heads = 8,
visual_enc_depth = 6,
visual_image_size = 256,
visual_patch_size = 32,
visual_heads = 8
).cuda()
# mock data
text = torch.randint(0, 49408, (4, 256)).cuda()
images = torch.randn(4, 3, 256, 256).cuda()
# decoder (with unet)
unet1 = Unet(
dim = 128,
image_embed_dim = 512,
text_embed_dim = 512,
cond_dim = 128,
channels = 3,
dim_mults=(1, 2, 4, 8)
).cuda()
unet2 = Unet(
dim = 16,
image_embed_dim = 512,
text_embed_dim = 512,
cond_dim = 128,
channels = 3,
dim_mults = (1, 2, 4, 8, 16),
cond_on_text_encodings = True
).cuda()
decoder = Decoder(
unet = (unet1, unet2),
image_sizes = (128, 256),
clip = clip,
timesteps = 1000,
condition_on_text_encodings = True
).cuda()
decoder_trainer = DecoderTrainer(
decoder,
lr = 3e-4,
wd = 1e-2,
ema_beta = 0.99,
ema_update_after_step = 1000,
ema_update_every = 10,
)
for unet_number in (1, 2):
loss = decoder_trainer(images, text = text, unet_number = unet_number) # use the decoder_trainer forward
loss.backward()
decoder_trainer.update(unet_number) # update the specific unet as well as its exponential moving average
# after much training
# you can sample from the exponentially moving averaged unets as so
mock_image_embed = torch.randn(4, 512).cuda()
images = decoder_trainer.sample(mock_image_embed, text = text) # (4, 3, 256, 256)
```
### Decoder Dataloaders
In order to make loading data simple and efficient, we include some general dataloaders that can be used to train portions of the network.
#### Decoder: Image Embedding Dataset
When training the decoder (and up samplers if training together) in isolation, you will need to load images and corresponding image embeddings. This dataset can read two similar types of datasets. First, it can read a [webdataset](https://github.com/webdataset/webdataset) that contains `.jpg` and `.npy` files in the `.tar`s that contain the images and associated image embeddings respectively. Alternatively, you can also specify a source for the embeddings outside of the webdataset. In this case, the path to the embeddings should contain `.npy` files with the same shard numbers as the webdataset and there should be a correspondence between the filename of the `.jpg` and the index of the embedding in the `.npy`. So, for example, `0001.tar` from the webdataset with image `00010509.jpg` (the first 4 digits are the shard number and the last 4 are the index) in it should be paralleled by a `img_emb_0001.npy` which contains a NumPy array with the embedding at index 509.
Generating a dataset of this type:
1. Use [img2dataset](https://github.com/rom1504/img2dataset) to generate a webdataset.
2. Use [clip-retrieval](https://github.com/rom1504/clip-retrieval) to convert the images to embeddings.
3. Use [embedding-dataset-reordering](https://github.com/Veldrovive/embedding-dataset-reordering) to reorder the embeddings into the expected format.
Usage:
```python
from dalle2_pytorch.dataloaders import ImageEmbeddingDataset, create_image_embedding_dataloader
# Create a dataloader directly.
dataloader = create_image_embedding_dataloader(
tar_url="/path/or/url/to/webdataset/{0000..9999}.tar", # Uses braket expanding notation. This specifies to read all tars from 0000.tar to 9999.tar
embeddings_url="path/or/url/to/embeddings/folder", # Included if .npy files are not in webdataset. Left out or set to None otherwise
num_workers=4,
batch_size=32,
shard_width=4, # If a file in the webdataset shard 3 is named 0003039.jpg, we know the shard width is 4 and the last three digits are the index
shuffle_num=200, # Does a shuffle of the data with a buffer size of 200
shuffle_shards=True, # Shuffle the order the shards are read in
resample_shards=False, # Sample shards with replacement. If true, an epoch will be infinite unless stopped manually
)
for img, emb in dataloader:
print(img.shape) # torch.Size([32, 3, 256, 256])
print(emb.shape) # torch.Size([32, 512])
# Train decoder only as shown above
# Or create a dataset without a loader so you can configure it manually
dataset = ImageEmbeddingDataset(
urls="/path/or/url/to/webdataset/{0000..9999}.tar",
embedding_folder_url="path/or/url/to/embeddings/folder",
shard_width=4,
shuffle_shards=True,
resample=False
)
```
## Scripts
### Using the `train_diffusion_prior.py` script
This script allows training the DiffusionPrior on pre-computed text and image embeddings. The working example below elucidates this process.
Please note that the script internally passes text_embed and image_embed to the DiffusionPrior, unlike the example below.
### Usage
```bash
$ pyhon train_diffusion_prior.py
```
The most significant parameters for the script are as follows:
--image-embed-url, default = "https://mystic.the-eye.eu/public/AI/cah/laion5b/embeddings/laion2B-en/img_emb/")
--text-embed-url, default = "https://mystic.the-eye.eu/public/AI/cah/laion5b/embeddings/laion2B-en/text_emb/")
--image-embed-dim, default=768 - 768 corresponds to the ViT iL/14 embedding size,change it to what your chosen ViT generates
--learning-rate, default=1.1e-4
--weight-decay, default=6.02e-2
--max-grad-norm, default=0.5
--batch-size, default=10 ** 4
--num-epochs, default=5
--clip, default=None # Signals the prior to use pre-computed embeddings
### Sample wandb run log
Please find a sample wandb run log at : https://wandb.ai/laion/diffusion-prior/runs/aul0rhv5?workspace=
Offer training wrappers
## CLI (wip)
@@ -898,26 +738,13 @@ Once built, images will be saved to the same directory the command is invoked
- [x] use inheritance just this once for sharing logic between decoder and prior network ddpms
- [x] bring in vit-vqgan https://arxiv.org/abs/2110.04627 for the latent diffusion
- [x] abstract interface for CLIP adapter class, so other CLIPs can be brought in
- [x] take care of mixed precision as well as gradient accumulation within decoder trainer
- [x] just take care of the training for the decoder in a wrapper class, as each unet in the cascade will need its own optimizer
- [x] bring in tools to train vqgan-vae
- [x] add convnext backbone for vqgan-vae (in addition to vit [vit-vqgan] + resnet)
- [x] make sure DDPMs can be run with traditional resnet blocks (but leave convnext as an option for experimentation)
- [x] make sure for the latter unets in the cascade, one can train on crops for learning super resolution (constrain the unet to be only convolutions in that case, or allow conv-like attention with rel pos bias)
- [ ] become an expert with unets, cleanup unet code, make it fully configurable, port all learnings over to https://github.com/lucidrains/x-unet (test out unet² in ddpm repo) - consider https://github.com/lucidrains/uformer-pytorch attention-based unet
- [ ] become an expert with unets, cleanup unet code, make it fully configurable, port all learnings over to https://github.com/lucidrains/x-unet
- [ ] copy the cascading ddpm code to a separate repo (perhaps https://github.com/lucidrains/denoising-diffusion-pytorch) as the main contribution of dalle2 really is just the prior network
- [ ] transcribe code to Jax, which lowers the activation energy for distributed training, given access to TPUs
- [ ] pull logic for training diffusion prior into a class DiffusionPriorTrainer, for eventual script based + CLI based training
- [ ] train on a toy task, offer in colab
- [ ] think about how best to design a declarative training config that handles preencoding for prior and training of multiple networks in decoder
- [ ] extend diffusion head to use diffusion-gan (potentially using lightweight-gan) to speed up inference
- [ ] bring in cross-scale embedding from iclr paper https://github.com/lucidrains/vit-pytorch/blob/main/vit_pytorch/crossformer.py#L14
- [ ] figure out if possible to augment with external memory, as described in https://arxiv.org/abs/2204.11824
- [ ] test out grid attention in cascading ddpm locally, decide whether to keep or remove
- [ ] use an experimental tracker agnostic setup, as done <a href="https://github.com/lucidrains/tf-bind-transformer#simple-trainer-class-for-fine-tuning">here</a>
- [ ] interface out the vqgan-vae so a pretrained one can be pulled off the shelf to validate latent diffusion + DALL-E2
- [ ] make sure FILIP works with DALL-E2 from x-clip https://arxiv.org/abs/2111.07783
- [ ] make sure resnet hyperparameters can be configurable across unet depth (groups and expansion factor)
- [ ] bring in tools to train vqgan-vae
## Citations
@@ -948,12 +775,10 @@ Once built, images will be saved to the same directory the command is invoked
```
```bibtex
@article{shen2019efficient,
author = {Zhuoran Shen and Mingyuan Zhang and Haiyu Zhao and Shuai Yi and Hongsheng Li},
title = {Efficient Attention: Attention with Linear Complexities},
journal = {CoRR},
year = {2018},
url = {http://arxiv.org/abs/1812.01243},
@inproceedings{Liu2022ACF,
title = {A ConvNet for the 2020https://arxiv.org/abs/2112.11435s},
author = {Zhuang Liu and Hanzi Mao and Chaozheng Wu and Christoph Feichtenhofer and Trevor Darrell and Saining Xie},
year = {2022}
}
```
@@ -975,14 +800,4 @@ Once built, images will be saved to the same directory the command is invoked
}
```
```bibtex
@article{Shleifer2021NormFormerIT,
title = {NormFormer: Improved Transformer Pretraining with Extra Normalization},
author = {Sam Shleifer and Jason Weston and Myle Ott},
journal = {ArXiv},
year = {2021},
volume = {abs/2110.09456}
}
```
*Creating noise from data is easy; creating data from noise is generative modeling.* - <a href="https://arxiv.org/abs/2011.13456">Yang Song's paper</a>
*Creating noise from data is easy; creating data from noise is generative modeling.* - Yang Song's <a href="https://arxiv.org/abs/2011.13456">paper</a>

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@@ -1,6 +1,5 @@
from dalle2_pytorch.dalle2_pytorch import DALLE2, DiffusionPriorNetwork, DiffusionPrior, Unet, Decoder
from dalle2_pytorch.dalle2_pytorch import OpenAIClipAdapter
from dalle2_pytorch.train import DecoderTrainer
from dalle2_pytorch.vqgan_vae import VQGanVAE
from x_clip import CLIP

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@@ -1,7 +1,6 @@
import click
import torch
import torchvision.transforms as T
from functools import reduce
from pathlib import Path
from dalle2_pytorch import DALLE2, Decoder, DiffusionPrior

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@@ -3,7 +3,6 @@ from tqdm import tqdm
from inspect import isfunction
from functools import partial
from contextlib import contextmanager
from collections import namedtuple
import torch
import torch.nn.functional as F
@@ -16,13 +15,10 @@ from einops_exts import rearrange_many, repeat_many, check_shape
from einops_exts.torch import EinopsToAndFrom
from kornia.filters import gaussian_blur2d
import kornia.augmentation as K
from dalle2_pytorch.tokenizer import tokenizer
from dalle2_pytorch.vqgan_vae import NullVQGanVAE, VQGanVAE
from resize_right import resize
# use x-clip
from x_clip import CLIP
@@ -32,9 +28,6 @@ from x_clip import CLIP
def exists(val):
return val is not None
def identity(t, *args, **kwargs):
return t
def default(val, d):
if exists(val):
return val
@@ -88,14 +81,14 @@ def freeze_model_and_make_eval_(model):
def l2norm(t):
return F.normalize(t, dim = -1)
def resize_image_to(image, target_image_size):
orig_image_size = image.shape[-1]
def resize_image_to(t, image_size, mode = 'bilinear'): # take a look at https://github.com/assafshocher/ResizeRight
shape = cast_tuple(image_size, 2)
orig_image_size = t.shape[-2:]
if orig_image_size == target_image_size:
return image
if orig_image_size == shape:
return t
scale_factors = target_image_size / orig_image_size
return resize(image, scale_factors = scale_factors)
return F.interpolate(t, size = shape, mode = mode, align_corners = False)
# image normalization functions
# ddpms expect images to be in the range of -1 to 1
@@ -109,9 +102,6 @@ def unnormalize_img(normed_img):
# clip related adapters
EmbeddedText = namedtuple('EmbedTextReturn', ['text_embed', 'text_encodings', 'text_mask'])
EmbeddedImage = namedtuple('EmbedImageReturn', ['image_embed', 'image_encodings'])
class BaseClipAdapter(nn.Module):
def __init__(self, clip):
super().__init__()
@@ -163,7 +153,7 @@ class XClipAdapter(BaseClipAdapter):
encoder_output = self.clip.text_transformer(text)
text_cls, text_encodings = encoder_output[:, 0], encoder_output[:, 1:]
text_embed = self.clip.to_text_latent(text_cls)
return EmbeddedText(l2norm(text_embed), text_encodings, text_mask)
return l2norm(text_embed), text_encodings, text_mask
@torch.no_grad()
def embed_image(self, image):
@@ -171,20 +161,24 @@ class XClipAdapter(BaseClipAdapter):
encoder_output = self.clip.visual_transformer(image)
image_cls, image_encodings = encoder_output[:, 0], encoder_output[:, 1:]
image_embed = self.clip.to_visual_latent(image_cls)
return EmbeddedImage(l2norm(image_embed), image_encodings)
return l2norm(image_embed), image_encodings
class OpenAIClipAdapter(BaseClipAdapter):
def __init__(
self,
name = 'ViT-B/32'
):
import clip
openai_clip, preprocess = clip.load(name)
try:
import clip
except ImportError:
print('you must install openai clip in order to use this adapter - `pip install git+https://github.com/openai/CLIP.git` - more instructions at https://github.com/openai/CLIP#usage')
openai_clip, _ = clip.load(name)
super().__init__(openai_clip)
text_attention_final = self.find_layer('ln_final')
self.handle = text_attention_final.register_forward_hook(self._hook)
self.clip_normalize = preprocess.transforms[-1]
self.clip_normalize = T.Normalize((0.48145466, 0.4578275, 0.40821073), (0.26862954, 0.26130258, 0.27577711))
self.cleared = False
def find_layer(self, layer):
@@ -225,7 +219,7 @@ class OpenAIClipAdapter(BaseClipAdapter):
text_embed = self.clip.encode_text(text)
text_encodings = self.text_encodings
del self.text_encodings
return EmbeddedText(text_embed.float(), text_encodings.float(), text_mask)
return text_embed.float(), text_encodings.float(), text_mask
@torch.no_grad()
def embed_image(self, image):
@@ -233,7 +227,7 @@ class OpenAIClipAdapter(BaseClipAdapter):
image = resize_image_to(image, self.image_size)
image = self.clip_normalize(unnormalize_img(image))
image_embed = self.clip.encode_image(image)
return EmbeddedImage(image_embed.float(), None)
return image_embed.float(), None
# classifier free guidance functions
@@ -502,12 +496,7 @@ class SwiGLU(nn.Module):
x, gate = x.chunk(2, dim = -1)
return x * F.silu(gate)
def FeedForward(
dim,
mult = 4,
dropout = 0.,
post_activation_norm = False
):
def FeedForward(dim, mult = 4, dropout = 0., post_activation_norm = False):
""" post-activation norm https://arxiv.org/abs/2110.09456 """
inner_dim = int(mult * dim)
@@ -530,8 +519,7 @@ class Attention(nn.Module):
dim_head = 64,
heads = 8,
dropout = 0.,
causal = False,
post_norm = False
causal = False
):
super().__init__()
self.scale = dim_head ** -0.5
@@ -546,11 +534,7 @@ class Attention(nn.Module):
self.null_kv = nn.Parameter(torch.randn(2, dim_head))
self.to_q = nn.Linear(dim, inner_dim, bias = False)
self.to_kv = nn.Linear(dim, dim_head * 2, bias = False)
self.to_out = nn.Sequential(
nn.Linear(inner_dim, dim, bias = False),
LayerNorm(dim) if post_norm else nn.Identity()
)
self.to_out = nn.Linear(inner_dim, dim, bias = False)
def forward(self, x, mask = None, attn_bias = None):
b, n, device = *x.shape[:2], x.device
@@ -612,11 +596,10 @@ class CausalTransformer(nn.Module):
dim_head = 64,
heads = 8,
ff_mult = 4,
norm_out = True,
norm_out = False,
attn_dropout = 0.,
ff_dropout = 0.,
final_proj = True,
normformer = False
final_proj = True
):
super().__init__()
self.rel_pos_bias = RelPosBias(heads = heads)
@@ -624,8 +607,8 @@ class CausalTransformer(nn.Module):
self.layers = nn.ModuleList([])
for _ in range(depth):
self.layers.append(nn.ModuleList([
Attention(dim = dim, causal = True, dim_head = dim_head, heads = heads, dropout = attn_dropout, post_norm = normformer),
FeedForward(dim = dim, mult = ff_mult, dropout = ff_dropout, post_activation_norm = normformer)
Attention(dim = dim, causal = True, dim_head = dim_head, heads = heads, dropout = attn_dropout),
FeedForward(dim = dim, mult = ff_mult, dropout = ff_dropout)
]))
self.norm = LayerNorm(dim) if norm_out else nn.Identity() # unclear in paper whether they projected after the classic layer norm for the final denoised image embedding, or just had the transformer output it directly: plan on offering both options
@@ -701,14 +684,14 @@ class DiffusionPriorNetwork(nn.Module):
# classifier free guidance
keep_mask = prob_mask_like((batch,), 1 - cond_drop_prob, device = device)
keep_mask = rearrange(keep_mask, 'b -> b 1')
cond_prob_mask = prob_mask_like((batch,), cond_drop_prob, device = device)
cond_prob_mask = rearrange(cond_prob_mask, 'b -> b 1')
mask &= keep_mask
mask &= cond_prob_mask
# whether text embedding is masked or not depends on the classifier free guidance conditional masking
mask = torch.cat((mask, keep_mask), dim = 1)
mask = torch.cat((mask, cond_prob_mask), dim = 1)
# whether text embedding is used for conditioning depends on whether text encodings are available for attention (for classifier free guidance, even though it seems from the paper it was not used in the prior ddpm, as the objective is different)
# but let's just do it right
@@ -753,8 +736,6 @@ class DiffusionPrior(BaseGaussianDiffusion):
predict_x_start = True,
beta_schedule = "cosine",
condition_on_text_encodings = True, # the paper suggests this is needed, but you can turn it off for your CLIP preprocessed text embed -> image embed training
sampling_clamp_l2norm = False,
image_embed_scale = None, # this is for scaling the l2-normed image embedding, so it is more suitable for gaussian diffusion, as outlined by Katherine (@crowsonkb) https://github.com/lucidrains/DALLE2-pytorch/issues/60#issue-1226116132
):
super().__init__(
beta_schedule = beta_schedule,
@@ -780,14 +761,8 @@ class DiffusionPrior(BaseGaussianDiffusion):
self.cond_drop_prob = cond_drop_prob
self.condition_on_text_encodings = condition_on_text_encodings
# in paper, they do not predict the noise, but predict x0 directly for image embedding, claiming empirically better results. I'll just offer both.
self.predict_x_start = predict_x_start
# @crowsonkb 's suggestion - https://github.com/lucidrains/DALLE2-pytorch/issues/60#issue-1226116132
self.image_embed_scale = default(image_embed_scale, image_embed_dim ** 0.5)
# whether to force an l2norm, similar to clipping denoised, when sampling
self.sampling_clamp_l2norm = sampling_clamp_l2norm
# in paper, they do not predict the noise, but predict x0 directly for image embedding, claiming empirically better results. I'll just offer both.
def p_mean_variance(self, x, t, text_cond, clip_denoised: bool):
pred = self.net(x, t, **text_cond)
@@ -802,13 +777,10 @@ class DiffusionPrior(BaseGaussianDiffusion):
if clip_denoised and not self.predict_x_start:
x_recon.clamp_(-1., 1.)
if self.predict_x_start and self.sampling_clamp_l2norm:
x_recon = l2norm(x_recon) * self.image_embed_scale
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.inference_mode()
@torch.no_grad()
def p_sample(self, x, t, text_cond = None, 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, text_cond = text_cond, clip_denoised = clip_denoised)
@@ -817,7 +789,7 @@ class DiffusionPrior(BaseGaussianDiffusion):
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.inference_mode()
@torch.no_grad()
def p_sample_loop(self, shape, text_cond):
device = self.betas.device
@@ -845,7 +817,7 @@ class DiffusionPrior(BaseGaussianDiffusion):
loss = self.loss_fn(pred, target)
return loss
@torch.inference_mode()
@torch.no_grad()
@eval_decorator
def sample(self, text, num_samples_per_batch = 2):
# in the paper, what they did was
@@ -863,11 +835,6 @@ class DiffusionPrior(BaseGaussianDiffusion):
text_cond = {**text_cond, 'text_encodings': text_encodings, 'mask': text_mask}
image_embeds = self.p_sample_loop((batch_size, image_embed_dim), text_cond = text_cond)
# retrieve original unscaled image embed
image_embeds /= self.image_embed_scale
text_embeds = text_cond['text_embed']
text_embeds = rearrange(text_embeds, '(b r) d -> b r d', r = num_samples_per_batch)
@@ -915,10 +882,6 @@ class DiffusionPrior(BaseGaussianDiffusion):
batch, device = image_embed.shape[0], image_embed.device
times = torch.randint(0, self.num_timesteps, (batch,), device = device, dtype = torch.long)
# scale image embed (Katherine)
image_embed *= self.image_embed_scale
# calculate forward loss
return self.p_losses(image_embed, times, text_cond = text_cond, *args, **kwargs)
@@ -943,41 +906,20 @@ class SinusoidalPosEmb(nn.Module):
emb = rearrange(x, 'i -> i 1') * rearrange(emb, 'j -> 1 j')
return torch.cat((emb.sin(), emb.cos()), dim = -1)
class Block(nn.Module):
def __init__(
self,
dim,
dim_out,
groups = 8
):
super().__init__()
self.block = nn.Sequential(
nn.Conv2d(dim, dim_out, 3, padding = 1),
nn.GroupNorm(groups, dim_out),
nn.SiLU()
)
def forward(self, x):
return self.block(x)
class ConvNextBlock(nn.Module):
""" https://arxiv.org/abs/2201.03545 """
class ResnetBlock(nn.Module):
def __init__(
self,
dim,
dim_out,
*,
cond_dim = None,
time_cond_dim = None,
groups = 8
mult = 2,
norm = True
):
super().__init__()
self.time_mlp = None
if exists(time_cond_dim):
self.time_mlp = nn.Sequential(
nn.SiLU(),
nn.Linear(time_cond_dim, dim_out)
)
need_projection = dim != dim_out
self.cross_attn = None
@@ -986,27 +928,32 @@ class ResnetBlock(nn.Module):
'b c h w',
'b (h w) c',
CrossAttention(
dim = dim_out,
dim = dim,
context_dim = cond_dim
)
)
self.block1 = Block(dim, dim_out, groups = groups)
self.block2 = Block(dim_out, dim_out, groups = groups)
self.res_conv = nn.Conv2d(dim, dim_out, 1) if dim != dim_out else nn.Identity()
self.ds_conv = nn.Conv2d(dim, dim, 7, padding = 3, groups = dim)
def forward(self, x, cond = None, time_emb = None):
h = self.block1(x)
inner_dim = int(dim_out * mult)
self.net = nn.Sequential(
ChanLayerNorm(dim) if norm else nn.Identity(),
nn.Conv2d(dim, inner_dim, 3, padding = 1),
nn.GELU(),
nn.Conv2d(inner_dim, dim_out, 3, padding = 1)
)
if exists(self.time_mlp) and exists(time_emb):
time_emb = self.time_mlp(time_emb)
h = rearrange(time_emb, 'b c -> b c 1 1') + h
self.res_conv = nn.Conv2d(dim, dim_out, 1) if need_projection else nn.Identity()
def forward(self, x, cond = None):
h = self.ds_conv(x)
if exists(self.cross_attn):
assert exists(cond)
h = self.cross_attn(h, context = cond) + h
h = self.block2(h)
h = self.net(h)
return h + self.res_conv(x)
class CrossAttention(nn.Module):
@@ -1083,46 +1030,6 @@ class GridAttention(nn.Module):
out = rearrange(out, '(b h w) (w1 w2) c -> b c (w1 h) (w2 w)', w1 = wsz, w2 = wsz, h = h // wsz, w = w // wsz)
return out
class LinearAttention(nn.Module):
def __init__(
self,
dim,
dim_head = 32,
heads = 8
):
super().__init__()
self.scale = dim_head ** -0.5
self.heads = heads
inner_dim = dim_head * heads
self.norm = ChanLayerNorm(dim)
self.nonlin = nn.GELU()
self.to_qkv = nn.Conv2d(dim, inner_dim * 3, 1, bias = False)
self.to_out = nn.Sequential(
nn.Conv2d(inner_dim, dim, 1, bias = False),
ChanLayerNorm(dim)
)
def forward(self, fmap):
h, x, y = self.heads, *fmap.shape[-2:]
fmap = self.norm(fmap)
q, k, v = self.to_qkv(fmap).chunk(3, dim = 1)
q, k, v = rearrange_many((q, k, v), 'b (h c) x y -> (b h) (x y) c', h = h)
q = q.softmax(dim = -1)
k = k.softmax(dim = -2)
q = q * self.scale
context = einsum('b n d, b n e -> b d e', k, v)
out = einsum('b n d, b d e -> b n e', q, context)
out = rearrange(out, '(b h) (x y) d -> b (h d) x y', h = h, x = x, y = y)
out = self.nonlin(out)
return self.to_out(out)
class Unet(nn.Module):
def __init__(
self,
@@ -1137,18 +1044,14 @@ class Unet(nn.Module):
dim_mults=(1, 2, 4, 8),
channels = 3,
attn_dim_head = 32,
attn_heads = 16,
attn_heads = 8,
lowres_cond = False, # for cascading diffusion - https://cascaded-diffusion.github.io/
sparse_attn = False,
sparse_attn_window = 8, # window size for sparse attention
attend_at_middle = True, # whether to have a layer of attention at the bottleneck (can turn off for higher resolution in cascading DDPM, before bringing in efficient attention)
cond_on_text_encodings = False,
max_text_len = 256,
cond_on_image_embeds = False,
init_dim = None,
init_conv_kernel_size = 7,
block_type = 'resnet',
block_resnet_groups = 8,
**kwargs
):
super().__init__()
# save locals to take care of some hyperparameters for cascading DDPM
@@ -1166,45 +1069,28 @@ class Unet(nn.Module):
self.channels = channels
init_channels = channels if not lowres_cond else channels * 2 # in cascading diffusion, one concats the low resolution image, blurred, for conditioning the higher resolution synthesis
init_dim = default(init_dim, dim // 2)
assert (init_conv_kernel_size % 2) == 1
self.init_conv = nn.Conv2d(init_channels, init_dim, init_conv_kernel_size, padding = init_conv_kernel_size // 2)
dims = [init_dim, *map(lambda m: dim * m, dim_mults)]
dims = [init_channels, *map(lambda m: dim * m, dim_mults)]
in_out = list(zip(dims[:-1], dims[1:]))
# time, image embeddings, and optional text encoding
cond_dim = default(cond_dim, dim)
time_cond_dim = dim * 4
self.to_time_hiddens = nn.Sequential(
self.time_mlp = nn.Sequential(
SinusoidalPosEmb(dim),
nn.Linear(dim, time_cond_dim),
nn.GELU()
)
self.to_time_tokens = nn.Sequential(
nn.Linear(time_cond_dim, cond_dim * num_time_tokens),
nn.Linear(dim, dim * 4),
nn.GELU(),
nn.Linear(dim * 4, cond_dim * num_time_tokens),
Rearrange('b (r d) -> b r d', r = num_time_tokens)
)
self.to_time_cond = nn.Sequential(
nn.Linear(time_cond_dim, time_cond_dim)
)
self.image_to_cond = nn.Sequential(
nn.Linear(image_embed_dim, cond_dim * num_image_tokens),
Rearrange('b (n d) -> b n d', n = num_image_tokens)
) if image_embed_dim != cond_dim else nn.Identity()
# text encoding conditioning (optional)
self.text_to_cond = None
if cond_on_text_encodings:
self.text_to_cond = nn.LazyLinear(cond_dim) if not exists(text_embed_dim) else nn.Linear(text_embed_dim, cond_dim)
self.text_to_cond = nn.LazyLinear(cond_dim) if not exists(text_embed_dim) else nn.Linear(text_embed_dim, cond_dim)
# finer control over whether to condition on image embeddings and text encodings
# so one can have the latter unets in the cascading DDPMs only focus on super-resoluting
@@ -1215,18 +1101,12 @@ class Unet(nn.Module):
# for classifier free guidance
self.null_image_embed = nn.Parameter(torch.randn(1, num_image_tokens, cond_dim))
self.max_text_len = max_text_len
self.null_text_embed = nn.Parameter(torch.randn(1, max_text_len, cond_dim))
# attention related params
attn_kwargs = dict(heads = attn_heads, dim_head = attn_dim_head)
# resnet block klass
block_klass = partial(ResnetBlock, groups = block_resnet_groups)
# layers
self.downs = nn.ModuleList([])
@@ -1239,32 +1119,32 @@ class Unet(nn.Module):
layer_cond_dim = cond_dim if not is_first else None
self.downs.append(nn.ModuleList([
block_klass(dim_in, dim_out, time_cond_dim = time_cond_dim),
Residual(LinearAttention(dim_out, **attn_kwargs)) if sparse_attn else nn.Identity(),
block_klass(dim_out, dim_out, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
ConvNextBlock(dim_in, dim_out, norm = ind != 0),
Residual(GridAttention(dim_out, window_size = sparse_attn_window, **attn_kwargs)) if sparse_attn else nn.Identity(),
ConvNextBlock(dim_out, dim_out, cond_dim = layer_cond_dim),
Downsample(dim_out) if not is_last else nn.Identity()
]))
mid_dim = dims[-1]
self.mid_block1 = block_klass(mid_dim, mid_dim, cond_dim = cond_dim, time_cond_dim = time_cond_dim)
self.mid_block1 = ConvNextBlock(mid_dim, mid_dim, cond_dim = cond_dim)
self.mid_attn = EinopsToAndFrom('b c h w', 'b (h w) c', Residual(Attention(mid_dim, **attn_kwargs))) if attend_at_middle else None
self.mid_block2 = block_klass(mid_dim, mid_dim, cond_dim = cond_dim, time_cond_dim = time_cond_dim)
self.mid_block2 = ConvNextBlock(mid_dim, mid_dim, cond_dim = cond_dim)
for ind, (dim_in, dim_out) in enumerate(reversed(in_out[1:])):
is_last = ind >= (num_resolutions - 2)
layer_cond_dim = cond_dim if not is_last else None
self.ups.append(nn.ModuleList([
block_klass(dim_out * 2, dim_in, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
Residual(LinearAttention(dim_in, **attn_kwargs)) if sparse_attn else nn.Identity(),
block_klass(dim_in, dim_in, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
ConvNextBlock(dim_out * 2, dim_in, cond_dim = layer_cond_dim),
Residual(GridAttention(dim_in, window_size = sparse_attn_window, **attn_kwargs)) if sparse_attn else nn.Identity(),
ConvNextBlock(dim_in, dim_in, cond_dim = layer_cond_dim),
Upsample(dim_in)
]))
out_dim = default(out_dim, channels)
self.final_conv = nn.Sequential(
block_klass(dim, dim),
ConvNextBlock(dim, dim),
nn.Conv2d(dim, out_dim, 1)
)
@@ -1294,7 +1174,7 @@ class Unet(nn.Module):
if cond_scale == 1:
return logits
null_logits = self.forward(*args, text_cond_drop_prob = 1., image_cond_drop_prob = 1., **kwargs)
null_logits = self.forward(*args, cond_drop_prob = 1., **kwargs)
return null_logits + (logits - null_logits) * cond_scale
def forward(
@@ -1305,9 +1185,7 @@ class Unet(nn.Module):
image_embed,
lowres_cond_img = None,
text_encodings = None,
text_mask = None,
image_cond_drop_prob = 0.,
text_cond_drop_prob = 0.,
cond_drop_prob = 0.,
blur_sigma = None,
blur_kernel_size = None
):
@@ -1320,23 +1198,14 @@ class Unet(nn.Module):
if exists(lowres_cond_img):
x = torch.cat((x, lowres_cond_img), dim = 1)
# initial convolution
x = self.init_conv(x)
# time conditioning
time_hiddens = self.to_time_hiddens(time)
time_tokens = self.to_time_tokens(time_hiddens)
t = self.to_time_cond(time_hiddens)
time_tokens = self.time_mlp(time)
# conditional dropout
image_keep_mask = prob_mask_like((batch_size,), 1 - image_cond_drop_prob, device = device)
text_keep_mask = prob_mask_like((batch_size,), 1 - text_cond_drop_prob, device = device)
image_keep_mask, text_keep_mask = rearrange_many((image_keep_mask, text_keep_mask), 'b -> b 1 1')
cond_prob_mask = prob_mask_like((batch_size,), cond_drop_prob, device = device)
cond_prob_mask = rearrange(cond_prob_mask, 'b -> b 1 1')
# mask out image embedding depending on condition dropout
# for classifier free guidance
@@ -1347,7 +1216,7 @@ class Unet(nn.Module):
image_tokens = self.image_to_cond(image_embed)
image_tokens = torch.where(
image_keep_mask,
cond_prob_mask,
image_tokens,
self.null_image_embed
)
@@ -1358,25 +1227,10 @@ class Unet(nn.Module):
if exists(text_encodings) and self.cond_on_text_encodings:
text_tokens = self.text_to_cond(text_encodings)
text_tokens = text_tokens[:, :self.max_text_len]
text_tokens_len = text_tokens.shape[1]
remainder = self.max_text_len - text_tokens_len
if remainder > 0:
text_tokens = F.pad(text_tokens, (0, 0, 0, remainder))
if exists(text_mask):
if remainder > 0:
text_mask = F.pad(text_mask, (0, remainder), value = False)
text_mask = rearrange(text_mask, 'b n -> b n 1')
text_keep_mask = text_mask & text_keep_mask
text_tokens = torch.where(
text_keep_mask,
cond_prob_mask,
text_tokens,
self.null_text_embed
self.null_text_embed[:, :text_tokens.shape[1]]
)
# main conditioning tokens (c)
@@ -1395,25 +1249,25 @@ class Unet(nn.Module):
hiddens = []
for block1, sparse_attn, block2, downsample in self.downs:
x = block1(x, c, t)
for convnext, sparse_attn, convnext2, downsample in self.downs:
x = convnext(x, c)
x = sparse_attn(x)
x = block2(x, c, t)
x = convnext2(x, c)
hiddens.append(x)
x = downsample(x)
x = self.mid_block1(x, mid_c, t)
x = self.mid_block1(x, mid_c)
if exists(self.mid_attn):
x = self.mid_attn(x)
x = self.mid_block2(x, mid_c, t)
x = self.mid_block2(x, mid_c)
for block1, sparse_attn, block2, upsample in self.ups:
for convnext, sparse_attn, convnext2, upsample in self.ups:
x = torch.cat((x, hiddens.pop()), dim=1)
x = block1(x, c, t)
x = convnext(x, c)
x = sparse_attn(x)
x = block2(x, c, t)
x = convnext2(x, c)
x = upsample(x)
return self.final_conv(x)
@@ -1421,11 +1275,13 @@ class Unet(nn.Module):
class LowresConditioner(nn.Module):
def __init__(
self,
cond_upsample_mode = 'bilinear',
downsample_first = True,
blur_sigma = 0.1,
blur_kernel_size = 3,
):
super().__init__()
self.cond_upsample_mode = cond_upsample_mode
self.downsample_first = downsample_first
self.blur_sigma = blur_sigma
self.blur_kernel_size = blur_kernel_size
@@ -1439,8 +1295,10 @@ class LowresConditioner(nn.Module):
blur_sigma = None,
blur_kernel_size = None
):
target_image_size = cast_tuple(target_image_size, 2)
if self.training and self.downsample_first and exists(downsample_image_size):
cond_fmap = resize_image_to(cond_fmap, downsample_image_size)
cond_fmap = resize_image_to(cond_fmap, downsample_image_size, mode = self.cond_upsample_mode)
if self.training:
# when training, blur the low resolution conditional image
@@ -1448,7 +1306,7 @@ class LowresConditioner(nn.Module):
blur_kernel_size = default(blur_kernel_size, self.blur_kernel_size)
cond_fmap = gaussian_blur2d(cond_fmap, cast_tuple(blur_kernel_size, 2), cast_tuple(blur_sigma, 2))
cond_fmap = resize_image_to(cond_fmap, target_image_size)
cond_fmap = resize_image_to(cond_fmap, target_image_size, mode = self.cond_upsample_mode)
return cond_fmap
@@ -1457,25 +1315,20 @@ class Decoder(BaseGaussianDiffusion):
self,
unet,
*,
clip = None,
image_size = None,
channels = 3,
clip,
vae = tuple(),
timesteps = 1000,
image_cond_drop_prob = 0.1,
text_cond_drop_prob = 0.5,
cond_drop_prob = 0.2,
loss_type = 'l1',
beta_schedule = 'cosine',
predict_x_start = False,
predict_x_start_for_latent_diffusion = False,
image_sizes = None, # for cascading ddpm, image size at each stage
random_crop_sizes = None, # whether to random crop the image at that stage in the cascade (super resoluting convolutions at the end may be able to generalize on smaller crops)
lowres_cond_upsample_mode = 'bilinear', # cascading ddpm - low resolution upsample mode
lowres_downsample_first = True, # cascading ddpm - resizes to lower resolution, then to next conditional resolution + blur
blur_sigma = 0.1, # cascading ddpm - blur sigma
blur_kernel_size = 3, # cascading ddpm - blur kernel size
condition_on_text_encodings = False, # the paper suggested that this didn't do much in the decoder, but i'm allowing the option for experimentation
clip_denoised = True,
clip_x_start = True
):
super().__init__(
beta_schedule = beta_schedule,
@@ -1483,22 +1336,15 @@ class Decoder(BaseGaussianDiffusion):
loss_type = loss_type
)
assert exists(clip) ^ exists(image_size), 'either CLIP is supplied, or you must give the image_size and channels (usually 3 for RGB)'
if isinstance(clip, CLIP):
clip = XClipAdapter(clip)
self.clip = None
if exists(clip):
if isinstance(clip, CLIP):
clip = XClipAdapter(clip)
freeze_model_and_make_eval_(clip)
assert isinstance(clip, BaseClipAdapter)
freeze_model_and_make_eval_(clip)
assert isinstance(clip, BaseClipAdapter)
self.clip = clip
self.clip_image_size = clip.image_size
self.channels = clip.image_channels
else:
self.clip_image_size = image_size
self.channels = channels
self.clip = clip
self.clip_image_size = clip.image_size
self.channels = clip.image_channels
self.condition_on_text_encodings = condition_on_text_encodings
@@ -1531,17 +1377,13 @@ class Decoder(BaseGaussianDiffusion):
# unet image sizes
image_sizes = default(image_sizes, (self.clip_image_size,))
image_sizes = default(image_sizes, (clip.image_size,))
image_sizes = tuple(sorted(set(image_sizes)))
assert len(self.unets) == len(image_sizes), f'you did not supply the correct number of u-nets ({len(self.unets)}) for resolutions {image_sizes}'
self.image_sizes = image_sizes
self.sample_channels = cast_tuple(self.channels, len(image_sizes))
# random crop sizes (for super-resoluting unets at the end of cascade?)
self.random_crop_sizes = cast_tuple(random_crop_sizes, len(image_sizes))
# predict x0 config
self.predict_x_start = cast_tuple(predict_x_start, len(unets)) if not predict_x_start_for_latent_diffusion else tuple(map(lambda t: isinstance(t, VQGanVAE), self.vaes))
@@ -1552,6 +1394,7 @@ class Decoder(BaseGaussianDiffusion):
assert lowres_conditions == (False, *((True,) * (len(self.unets) - 1))), 'the first unet must be unconditioned (by low resolution image), and the rest of the unets must have `lowres_cond` set to True'
self.to_lowres_cond = LowresConditioner(
cond_upsample_mode = lowres_cond_upsample_mode,
downsample_first = lowres_downsample_first,
blur_sigma = blur_sigma,
blur_kernel_size = blur_kernel_size,
@@ -1559,13 +1402,7 @@ class Decoder(BaseGaussianDiffusion):
# classifier free guidance
self.image_cond_drop_prob = image_cond_drop_prob
self.text_cond_drop_prob = text_cond_drop_prob
# whether to clip when sampling
self.clip_denoised = clip_denoised
self.clip_x_start = clip_x_start
self.cond_drop_prob = cond_drop_prob
def get_unet(self, unet_number):
assert 0 < unet_number <= len(self.unets)
@@ -1586,31 +1423,37 @@ class Decoder(BaseGaussianDiffusion):
yield
unet.cpu()
def p_mean_variance(self, unet, x, t, image_embed, text_encodings = None, text_mask = None, lowres_cond_img = None, clip_denoised = True, predict_x_start = False, cond_scale = 1.):
pred = unet.forward_with_cond_scale(x, t, image_embed = image_embed, text_encodings = text_encodings, text_mask = text_mask, cond_scale = cond_scale, lowres_cond_img = lowres_cond_img)
@torch.no_grad()
def get_image_embed(self, image):
image_embed, _ = self.clip.embed_image(image)
return image_embed
def p_mean_variance(self, unet, x, t, image_embed, text_encodings = None, lowres_cond_img = None, clip_denoised = True, predict_x_start = False, cond_scale = 1.):
pred = unet.forward_with_cond_scale(x, t, image_embed = image_embed, text_encodings = text_encodings, cond_scale = cond_scale, lowres_cond_img = lowres_cond_img)
if predict_x_start:
x_recon = pred
else:
x_recon = self.predict_start_from_noise(x, t = t, noise = pred)
if clip_denoised:
if clip_denoised and not predict_x_start:
x_recon.clamp_(-1., 1.)
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.inference_mode()
def p_sample(self, unet, x, t, image_embed, text_encodings = None, text_mask = None, cond_scale = 1., lowres_cond_img = None, predict_x_start = False, clip_denoised = True, repeat_noise = False):
@torch.no_grad()
def p_sample(self, unet, x, t, image_embed, text_encodings = None, cond_scale = 1., lowres_cond_img = None, predict_x_start = False, clip_denoised = True, repeat_noise = False):
b, *_, device = *x.shape, x.device
model_mean, _, model_log_variance = self.p_mean_variance(unet, x = x, t = t, image_embed = image_embed, text_encodings = text_encodings, text_mask = text_mask, cond_scale = cond_scale, lowres_cond_img = lowres_cond_img, clip_denoised = clip_denoised, predict_x_start = predict_x_start)
model_mean, _, model_log_variance = self.p_mean_variance(unet, x = x, t = t, image_embed = image_embed, text_encodings = text_encodings, cond_scale = cond_scale, lowres_cond_img = lowres_cond_img, clip_denoised = clip_denoised, predict_x_start = predict_x_start)
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.inference_mode()
def p_sample_loop(self, unet, shape, image_embed, predict_x_start = False, clip_denoised = True, lowres_cond_img = None, text_encodings = None, text_mask = None, cond_scale = 1):
@torch.no_grad()
def p_sample_loop(self, unet, shape, image_embed, predict_x_start = False, lowres_cond_img = None, text_encodings = None, cond_scale = 1):
device = self.betas.device
b = shape[0]
@@ -1623,16 +1466,14 @@ class Decoder(BaseGaussianDiffusion):
torch.full((b,), i, device = device, dtype = torch.long),
image_embed = image_embed,
text_encodings = text_encodings,
text_mask = text_mask,
cond_scale = cond_scale,
lowres_cond_img = lowres_cond_img,
predict_x_start = predict_x_start,
clip_denoised = clip_denoised
predict_x_start = predict_x_start
)
return 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):
def p_losses(self, unet, x_start, times, *, image_embed, lowres_cond_img = None, text_encodings = None, predict_x_start = False, noise = None):
noise = default(noise, lambda: torch.randn_like(x_start))
x_noisy = self.q_sample(x_start = x_start, t = times, noise = noise)
@@ -1642,10 +1483,8 @@ class Decoder(BaseGaussianDiffusion):
times,
image_embed = image_embed,
text_encodings = text_encodings,
text_mask = text_mask,
lowres_cond_img = lowres_cond_img,
image_cond_drop_prob = self.image_cond_drop_prob,
text_cond_drop_prob = self.text_cond_drop_prob,
cond_drop_prob = self.cond_drop_prob
)
target = noise if not predict_x_start else x_start
@@ -1653,27 +1492,21 @@ class Decoder(BaseGaussianDiffusion):
loss = self.loss_fn(pred, target)
return loss
@torch.inference_mode()
@torch.no_grad()
@eval_decorator
def sample(
self,
image_embed,
text = None,
cond_scale = 1.,
stop_at_unet_number = None
):
def sample(self, image_embed, text = None, cond_scale = 1.):
batch_size = image_embed.shape[0]
text_encodings = text_mask = None
text_encodings = None
if exists(text):
_, text_encodings, text_mask = self.clip.embed_text(text)
_, text_encodings, _ = 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'
assert not (not self.condition_on_text_encodings and exists(text_encodings)), 'decoder specified not to be conditioned on text, yet it is presented'
img = None
for unet_number, unet, vae, channel, image_size, predict_x_start in tqdm(zip(range(1, len(self.unets) + 1), self.unets, self.vaes, self.sample_channels, self.image_sizes, self.predict_x_start)):
for unet, vae, channel, image_size, predict_x_start in tqdm(zip(self.unets, self.vaes, self.sample_channels, self.image_sizes, self.predict_x_start)):
context = self.one_unet_in_gpu(unet = unet) if image_embed.is_cuda else null_context()
@@ -1684,7 +1517,6 @@ class Decoder(BaseGaussianDiffusion):
if unet.lowres_cond:
lowres_cond_img = self.to_lowres_cond(img, target_image_size = image_size)
is_latent_diffusion = isinstance(vae, VQGanVAE)
image_size = vae.get_encoded_fmap_size(image_size)
shape = (batch_size, vae.encoded_dim, image_size, image_size)
@@ -1696,18 +1528,13 @@ class Decoder(BaseGaussianDiffusion):
shape,
image_embed = image_embed,
text_encodings = text_encodings,
text_mask = text_mask,
cond_scale = cond_scale,
predict_x_start = predict_x_start,
clip_denoised = not is_latent_diffusion,
lowres_cond_img = lowres_cond_img
)
img = vae.decode(img)
if exists(stop_at_unet_number) and stop_at_unet_number == unet_number:
break
return img
def forward(
@@ -1724,10 +1551,10 @@ class Decoder(BaseGaussianDiffusion):
unet = self.get_unet(unet_number)
vae = self.vaes[unet_index]
target_image_size = self.image_sizes[unet_index]
predict_x_start = self.predict_x_start[unet_index]
random_crop_size = self.random_crop_sizes[unet_index]
target_image_size = self.image_sizes[unet_index]
vae = self.vaes[unet_index]
predict_x_start = self.predict_x_start[unet_index]
b, c, h, w, device, = *image.shape, image.device
check_shape(image, 'b c h w', c = self.channels)
@@ -1736,13 +1563,11 @@ class Decoder(BaseGaussianDiffusion):
times = torch.randint(0, self.num_timesteps, (b,), device = device, dtype = torch.long)
if not exists(image_embed):
assert exists(self.clip), 'if you want to derive CLIP image embeddings automatically, you must supply `clip` to the decoder on init'
image_embed, _ = self.clip.embed_image(image)
text_encodings = text_mask = None
text_encodings = None
if exists(text) and not exists(text_encodings):
assert exists(self.clip), 'if you are passing in raw text, you need to supply `clip` to the decoder'
_, text_encodings, text_mask = self.clip.embed_text(text)
_, text_encodings, _ = 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'
assert not (not self.condition_on_text_encodings and exists(text_encodings)), 'decoder specified not to be conditioned on text, yet it is presented'
@@ -1750,14 +1575,6 @@ class Decoder(BaseGaussianDiffusion):
lowres_cond_img = self.to_lowres_cond(image, target_image_size = target_image_size, downsample_image_size = self.image_sizes[unet_index - 1]) if unet_number > 1 else None
image = resize_image_to(image, target_image_size)
if exists(random_crop_size):
aug = K.RandomCrop((random_crop_size, random_crop_size), p = 1.)
# make sure low res conditioner and image both get augmented the same way
# detailed https://kornia.readthedocs.io/en/latest/augmentation.module.html?highlight=randomcrop#kornia.augmentation.RandomCrop
image = aug(image)
lowres_cond_img = aug(lowres_cond_img, params = aug._params)
vae.eval()
with torch.no_grad():
image = vae.encode(image)
@@ -1765,7 +1582,7 @@ class Decoder(BaseGaussianDiffusion):
if exists(lowres_cond_img):
lowres_cond_img = 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)
return self.p_losses(unet, image, times, image_embed = image_embed, text_encodings = text_encodings, lowres_cond_img = lowres_cond_img, predict_x_start = predict_x_start)
# main class
@@ -1788,7 +1605,7 @@ class DALLE2(nn.Module):
self.to_pil = T.ToPILImage()
@torch.inference_mode()
@torch.no_grad()
@eval_decorator
def forward(
self,
@@ -1815,3 +1632,4 @@ class DALLE2(nn.Module):
return images[0]
return images

View File

@@ -1 +0,0 @@
from dalle2_pytorch.dataloaders.decoder_loader import ImageEmbeddingDataset, create_image_embedding_dataloader

View File

@@ -1,170 +0,0 @@
import os
import webdataset as wds
import torch
import numpy as np
import fsspec
def get_shard(filename):
"""
Filenames with shards in them have a consistent structure that we can take advantage of
Standard structure: path/to/file/prefix_string_00001.ext
"""
try:
return filename.split("_")[-1].split(".")[0]
except ValueError:
raise RuntimeError(f"Could not find shard for filename {filename}")
def get_example_file(fs, path, file_format):
"""
Given a file system and a file extension, return the example file
"""
return fs.glob(os.path.join(path, f"*.{file_format}"))[0]
def embedding_inserter(samples, embeddings_url, shard_width, handler=wds.handlers.reraise_exception):
"""Given a datum of {"__key__": str, "__url__": str, ...} adds the cooresponding embedding and yields"""
previous_tar_url = None
current_embeddings = None
# Get a reference to an abstract file system where the embeddings are stored
embeddings_fs, embeddings_path = fsspec.core.url_to_fs(embeddings_url)
example_embedding_file = get_example_file(embeddings_fs, embeddings_path, "npy")
example_embedding_shard = get_shard(example_embedding_file)
emb_shard_width = len(example_embedding_shard)
# Easier to get the basename without the shard once than search through for the correct file every time
embedding_file_basename = '_'.join(example_embedding_file.split("_")[:-1]) + "_"
def load_corresponding_embeds(tar_url):
"""Finds and reads the npy files that contains embeddings for the given webdataset tar"""
shard = int(tar_url.split("/")[-1].split(".")[0])
embedding_url = embedding_file_basename + str(shard).zfill(emb_shard_width) + '.npy'
with embeddings_fs.open(embedding_url) as f:
data = np.load(f)
return torch.from_numpy(data)
for sample in samples:
try:
tar_url = sample["__url__"]
key = sample["__key__"]
if tar_url != previous_tar_url:
# If the tar changed, we need to download new embeddings
# This means if we shuffle before inserting it will load many more files than we expect and be very inefficient.
previous_tar_url = tar_url
current_embeddings = load_corresponding_embeds(tar_url)
embedding_index = int(key[shard_width:])
sample["npy"] = current_embeddings[embedding_index]
yield sample
except Exception as exn: # From wds implementation
if handler(exn):
continue
else:
break
insert_embedding = wds.filters.pipelinefilter(embedding_inserter)
def verify_keys(samples, handler=wds.handlers.reraise_exception):
"""
Requires that both the image and embedding are present in the sample
This is important to do as a user may forget they do not have embeddings in their webdataset and neglect to add them using the embedding_folder_url parameter.
"""
for sample in samples:
try:
assert "jpg" in sample, f"Sample {sample['__key__']} missing image"
assert "npy" in sample, f"Sample {sample['__key__']} missing embedding. Did you set embedding_folder_url?"
yield sample
except Exception as exn: # From wds implementation
if handler(exn):
continue
else:
break
class ImageEmbeddingDataset(wds.DataPipeline, wds.compat.FluidInterface):
"""
A fluid interface wrapper for DataPipline that returns image embedding pairs
Reads embeddings as npy files from the webdataset if they exist. If embedding_folder_url is set, they will be inserted in from the alternate source.
"""
def __init__(
self,
urls,
embedding_folder_url=None,
shard_width=None,
handler=wds.handlers.reraise_exception,
resample=False,
shuffle_shards=True
):
"""
Modeled directly off of the WebDataset constructor
:param urls: A url pointing to the tar files of the webdataset formatted as /path/to/webdataset/{0000..9999}.tar
:param embedding_folder_url: Required if webdataset does not contain embeddings. A url pointing to the npy files of the embeddings. Should have the same number of shards as the webdataset.
Webdataset image keys should align with the index of the embedding. This means missing image indices must have a corresponding embedding of all zeros.
:param shard_width: The number of digits in the shard number. This is used to align the embedding index with the image index.
For example, if a file in the webdataset shard 3 is named 0003039.jpg, we know the shard with this 4 and the last three digits are the index.
:param handler: A webdataset handler.
:param resample: If true, resample webdataset shards with replacement. You need to set your own epoch size if this is true since it will resample infinitely.
:param shuffle_shards: If true, shuffle the shards before resampling. This cannot be true if resample is true.
"""
super().__init__()
# Add the shardList and randomize or resample if requested
if resample:
assert not shuffle_shards, "Cannot both resample and shuffle"
self.append(wds.ResampledShards(urls))
else:
self.append(wds.SimpleShardList(urls))
if shuffle_shards:
self.append(wds.filters.shuffle(1000))
self.append(wds.split_by_node)
self.append(wds.split_by_worker)
self.append(wds.tarfile_to_samples(handler=handler))
self.append(wds.decode("torchrgb"))
if embedding_folder_url is not None:
assert shard_width is not None, "Reading embeddings separately requires shard length to be given"
self.append(insert_embedding(embeddings_url=embedding_folder_url, shard_width=shard_width, handler=handler))
self.append(verify_keys)
self.append(wds.to_tuple("jpg", "npy"))
def create_image_embedding_dataloader(
tar_url,
num_workers,
batch_size,
embeddings_url=None,
shard_width=None,
shuffle_num = None,
shuffle_shards = True,
resample_shards = False,
handler=wds.handlers.warn_and_continue
):
"""
Convenience function to create an image embedding dataseta and dataloader in one line
:param tar_url: A url pointing to the tar files of the webdataset formatted as /path/to/webdataset/{0000..9999}.tar
:param num_workers: The number of workers to use for the dataloader
:param batch_size: The batch size to use for the dataloader
:param embeddings_url: Required if webdataset does not contain embeddings. A url pointing to the npy files of the embeddings. Should have the same number of shards as the webdataset.
Webdataset image keys should align with the index of the embedding. This means missing image indices must have a corresponding embedding of all zeros.
:param shard_width: The number of digits in the shard number. This is used to align the embedding index with the image index.
For example, if a file in the webdataset shard 3 is named 0003039.jpg, we know the shard width is 4 and the last three digits are the index.
:param shuffle_num: If not None, shuffle the dataset with this size buffer after sampling.
:param shuffle_shards: If true, shuffle the shards before sampling. This cannot be true if resample is true.
:param resample_shards: If true, resample webdataset shards with replacement. You need to set your own epoch size if this is true since it will resample infinitely.
:param handler: A webdataset handler.
"""
ds = ImageEmbeddingDataset(
tar_url,
embeddings_url,
shard_width=shard_width,
shuffle_shards=shuffle_shards,
resample=resample_shards,
handler=handler
)
if shuffle_num is not None and shuffle_num > 0:
ds.shuffle(1000)
return wds.WebLoader(
ds,
num_workers=num_workers,
batch_size=batch_size,
prefetch_factor=2, # This might be good to have high so the next npy file is prefetched
pin_memory=True,
shuffle=False
)

View File

@@ -1,29 +0,0 @@
from torch.optim import AdamW, Adam
def separate_weight_decayable_params(params):
no_wd_params = set([param for param in params if param.ndim < 2])
wd_params = set(params) - no_wd_params
return wd_params, no_wd_params
def get_optimizer(
params,
lr = 3e-4,
wd = 1e-2,
betas = (0.9, 0.999),
filter_by_requires_grad = False
):
if filter_by_requires_grad:
params = list(filter(lambda t: t.requires_grad, params))
if wd == 0:
return Adam(params, lr = lr, betas = betas)
params = set(params)
wd_params, no_wd_params = separate_weight_decayable_params(params)
param_groups = [
{'params': list(wd_params)},
{'params': list(no_wd_params), 'weight_decay': 0},
]
return AdamW(param_groups, lr = lr, weight_decay = wd, betas = betas)

View File

@@ -1,43 +1,6 @@
import copy
from functools import partial
import torch
from torch import nn
from torch.cuda.amp import autocast, GradScaler
from dalle2_pytorch.dalle2_pytorch import Decoder
from dalle2_pytorch.optimizer import get_optimizer
# helper functions
def exists(val):
return val is not None
def cast_tuple(val, length = 1):
return val if isinstance(val, tuple) else ((val,) * length)
def pick_and_pop(keys, d):
values = list(map(lambda key: d.pop(key), keys))
return dict(zip(keys, values))
def group_dict_by_key(cond, d):
return_val = [dict(),dict()]
for key in d.keys():
match = bool(cond(key))
ind = int(not match)
return_val[ind][key] = d[key]
return (*return_val,)
def string_begins_with(prefix, str):
return str.startswith(prefix)
def group_by_key_prefix(prefix, d):
return group_dict_by_key(partial(string_begins_with, prefix), d)
def groupby_prefix_and_trim(prefix, d):
kwargs_with_prefix, kwargs = group_dict_by_key(partial(string_begins_with, 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
# exponential moving average wrapper
@@ -46,16 +9,16 @@ class EMA(nn.Module):
self,
model,
beta = 0.99,
update_after_step = 1000,
update_every = 10,
ema_update_after_step = 1000,
ema_update_every = 10,
):
super().__init__()
self.beta = beta
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.ema_update_after_step = ema_update_after_step # only start EMA after this step number, starting at 0
self.ema_update_every = ema_update_every
self.register_buffer('initted', torch.Tensor([False]))
self.register_buffer('step', torch.tensor([0.]))
@@ -63,7 +26,7 @@ class EMA(nn.Module):
def update(self):
self.step += 1
if self.step <= self.update_after_step or (self.step % self.update_every) != 0:
if self.step <= self.ema_update_after_step or (self.step % self.ema_update_every) != 0:
return
if not self.initted:
@@ -88,112 +51,3 @@ class EMA(nn.Module):
def __call__(self, *args, **kwargs):
return self.ema_model(*args, **kwargs)
# trainers
class DecoderTrainer(nn.Module):
def __init__(
self,
decoder,
use_ema = True,
lr = 3e-4,
wd = 1e-2,
max_grad_norm = None,
amp = False,
**kwargs
):
super().__init__()
assert isinstance(decoder, Decoder)
ema_kwargs, kwargs = groupby_prefix_and_trim('ema_', kwargs)
self.decoder = decoder
self.num_unets = len(self.decoder.unets)
self.use_ema = use_ema
if use_ema:
has_lazy_linear = any([type(module) == nn.LazyLinear for module in decoder.modules()])
assert not has_lazy_linear, 'you must set the text_embed_dim on your u-nets if you plan on doing automatic exponential moving average'
self.ema_unets = nn.ModuleList([])
self.amp = amp
# be able to finely customize learning rate, weight decay
# per unet
lr, wd = map(partial(cast_tuple, length = self.num_unets), (lr, wd))
for ind, (unet, unet_lr, unet_wd) in enumerate(zip(self.decoder.unets, lr, wd)):
optimizer = get_optimizer(
unet.parameters(),
lr = unet_lr,
wd = unet_wd,
**kwargs
)
setattr(self, f'optim{ind}', optimizer) # cannot use pytorch ModuleList for some reason with optimizers
if self.use_ema:
self.ema_unets.append(EMA(unet, **ema_kwargs))
scaler = GradScaler(enabled = amp)
setattr(self, f'scaler{ind}', scaler)
# gradient clipping if needed
self.max_grad_norm = max_grad_norm
@property
def unets(self):
return nn.ModuleList([ema.ema_model for ema in self.ema_unets])
def scale(self, loss, *, unet_number):
assert 1 <= unet_number <= self.num_unets
index = unet_number - 1
scaler = getattr(self, f'scaler{index}')
return scaler.scale(loss)
def update(self, unet_number):
assert 1 <= unet_number <= self.num_unets
index = unet_number - 1
unet = self.decoder.unets[index]
optimizer = getattr(self, f'optim{index}')
scaler = getattr(self, f'scaler{index}')
if exists(self.max_grad_norm):
scaler.unscale_(optimizer)
nn.utils.clip_grad_norm_(unet.parameters(), self.max_grad_norm)
scaler.step(optimizer)
scaler.update()
optimizer.zero_grad()
if self.use_ema:
ema_unet = self.ema_unets[index]
ema_unet.update()
@torch.no_grad()
def sample(self, *args, **kwargs):
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)
if self.use_ema:
self.decoder.unets = trainable_unets # restore original training unets
return output
def forward(
self,
x,
*,
unet_number,
divisor = 1,
**kwargs
):
with autocast(enabled = self.amp):
loss = self.decoder(x, unet_number = unet_number, **kwargs)
return self.scale(loss / divisor, unet_number = unet_number)

View File

@@ -1,266 +0,0 @@
from math import sqrt
import copy
from random import choice
from pathlib import Path
from shutil import rmtree
import torch
from torch import nn
from PIL import Image
from torchvision.datasets import ImageFolder
import torchvision.transforms as T
from torch.utils.data import Dataset, DataLoader, random_split
from torchvision.utils import make_grid, save_image
from einops import rearrange
from dalle2_pytorch.train import EMA
from dalle2_pytorch.vqgan_vae import VQGanVAE
from dalle2_pytorch.optimizer import get_optimizer
# helpers
def exists(val):
return val is not None
def noop(*args, **kwargs):
pass
def cycle(dl):
while True:
for data in dl:
yield data
def cast_tuple(t):
return t if isinstance(t, (tuple, list)) else (t,)
def yes_or_no(question):
answer = input(f'{question} (y/n) ')
return answer.lower() in ('yes', 'y')
def accum_log(log, new_logs):
for key, new_value in new_logs.items():
old_value = log.get(key, 0.)
log[key] = old_value + new_value
return log
# classes
class ImageDataset(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}')]
print(f'{len(self.paths)} training samples found at {folder}')
self.transform = T.Compose([
T.Lambda(lambda img: img.convert('RGB') if img.mode != 'RGB' else img),
T.Resize(image_size),
T.RandomHorizontalFlip(),
T.CenterCrop(image_size),
T.ToTensor()
])
def __len__(self):
return len(self.paths)
def __getitem__(self, index):
path = self.paths[index]
img = Image.open(path)
return self.transform(img)
# main trainer class
class VQGanVAETrainer(nn.Module):
def __init__(
self,
vae,
*,
num_train_steps,
lr,
batch_size,
folder,
grad_accum_every,
wd = 0.,
save_results_every = 100,
save_model_every = 1000,
results_folder = './results',
valid_frac = 0.05,
random_split_seed = 42,
ema_beta = 0.995,
ema_update_after_step = 2000,
ema_update_every = 10,
apply_grad_penalty_every = 4,
):
super().__init__()
assert isinstance(vae, VQGanVAE), 'vae must be instance of VQGanVAE'
image_size = vae.image_size
self.vae = vae
self.ema_vae = EMA(vae, update_after_step = ema_update_after_step, update_every = ema_update_every)
self.register_buffer('steps', torch.Tensor([0]))
self.num_train_steps = num_train_steps
self.batch_size = batch_size
self.grad_accum_every = grad_accum_every
all_parameters = set(vae.parameters())
discr_parameters = set(vae.discr.parameters())
vae_parameters = all_parameters - discr_parameters
self.optim = get_optimizer(vae_parameters, lr = lr, wd = wd)
self.discr_optim = get_optimizer(discr_parameters, lr = lr, wd = wd)
# create dataset
self.ds = ImageDataset(folder, image_size = image_size)
# split for validation
if valid_frac > 0:
train_size = int((1 - valid_frac) * len(self.ds))
valid_size = len(self.ds) - train_size
self.ds, self.valid_ds = random_split(self.ds, [train_size, valid_size], generator = torch.Generator().manual_seed(random_split_seed))
print(f'training with dataset of {len(self.ds)} samples and validating with randomly splitted {len(self.valid_ds)} samples')
else:
self.valid_ds = self.ds
print(f'training with shared training and valid dataset of {len(self.ds)} samples')
# dataloader
self.dl = cycle(DataLoader(
self.ds,
batch_size = batch_size,
shuffle = True
))
self.valid_dl = cycle(DataLoader(
self.valid_ds,
batch_size = batch_size,
shuffle = True
))
self.save_model_every = save_model_every
self.save_results_every = save_results_every
self.apply_grad_penalty_every = apply_grad_penalty_every
self.results_folder = Path(results_folder)
if len([*self.results_folder.glob('**/*')]) > 0 and yes_or_no('do you want to clear previous experiment checkpoints and results?'):
rmtree(str(self.results_folder))
self.results_folder.mkdir(parents = True, exist_ok = True)
def train_step(self):
device = next(self.vae.parameters()).device
steps = int(self.steps.item())
apply_grad_penalty = not (steps % self.apply_grad_penalty_every)
self.vae.train()
# logs
logs = {}
# update vae (generator)
for _ in range(self.grad_accum_every):
img = next(self.dl)
img = img.to(device)
loss = self.vae(
img,
return_loss = True,
apply_grad_penalty = apply_grad_penalty
)
accum_log(logs, {'loss': loss.item() / self.grad_accum_every})
(loss / self.grad_accum_every).backward()
self.optim.step()
self.optim.zero_grad()
# update discriminator
if exists(self.vae.discr):
discr_loss = 0
for _ in range(self.grad_accum_every):
img = next(self.dl)
img = img.to(device)
loss = self.vae(img, return_discr_loss = True)
accum_log(logs, {'discr_loss': loss.item() / self.grad_accum_every})
(loss / self.grad_accum_every).backward()
self.discr_optim.step()
self.discr_optim.zero_grad()
# log
print(f"{steps}: vae loss: {logs['loss']} - discr loss: {logs['discr_loss']}")
# update exponential moving averaged generator
self.ema_vae.update()
# sample results every so often
if not (steps % self.save_results_every):
for model, filename in ((self.ema_vae.ema_model, f'{steps}.ema'), (self.vae, str(steps))):
model.eval()
imgs = next(self.dl)
imgs = imgs.to(device)
recons = model(imgs)
nrows = int(sqrt(self.batch_size))
imgs_and_recons = torch.stack((imgs, recons), dim = 0)
imgs_and_recons = rearrange(imgs_and_recons, 'r b ... -> (b r) ...')
imgs_and_recons = imgs_and_recons.detach().cpu().float().clamp(0., 1.)
grid = make_grid(imgs_and_recons, nrow = 2, normalize = True, value_range = (0, 1))
logs['reconstructions'] = grid
save_image(grid, str(self.results_folder / f'{filename}.png'))
print(f'{steps}: saving to {str(self.results_folder)}')
# save model every so often
if not (steps % self.save_model_every):
state_dict = self.vae.state_dict()
model_path = str(self.results_folder / f'vae.{steps}.pt')
torch.save(state_dict, model_path)
ema_state_dict = self.ema_vae.state_dict()
model_path = str(self.results_folder / f'vae.{steps}.ema.pt')
torch.save(ema_state_dict, model_path)
print(f'{steps}: saving model to {str(self.results_folder)}')
self.steps += 1
return logs
def train(self, log_fn = noop):
device = next(self.vae.parameters()).device
while self.steps < self.num_train_steps:
logs = self.train_step()
log_fn(logs)
print('training complete')

View File

@@ -285,10 +285,6 @@ class ResnetEncDec(nn.Module):
def get_encoded_fmap_size(self, image_size):
return image_size // (2 ** self.layers)
@property
def last_dec_layer(self):
return self.decoders[-1].weight
def encode(self, x):
for enc in self.encoders:
x = enc(x)
@@ -508,10 +504,6 @@ class ViTEncDec(nn.Module):
def get_encoded_fmap_size(self, image_size):
return image_size // self.patch_size
@property
def last_dec_layer(self):
return self.decoder[-3][-1].weight
def encode(self, x):
return self.encoder(x)
@@ -747,7 +739,7 @@ class VQGanVAE(nn.Module):
# calculate adaptive weight
last_dec_layer = self.enc_dec.last_dec_layer
last_dec_layer = self.decoders[-1].weight
norm_grad_wrt_gen_loss = grad_layer_wrt_loss(gen_loss, last_dec_layer).norm(p = 2)
norm_grad_wrt_perceptual_loss = grad_layer_wrt_loss(perceptual_loss, last_dec_layer).norm(p = 2)

View File

@@ -10,7 +10,7 @@ setup(
'dream = dalle2_pytorch.cli:dream'
],
},
version = '0.0.106',
version = '0.0.67',
license='MIT',
description = 'DALL-E 2',
author = 'Phil Wang',
@@ -23,21 +23,16 @@ setup(
],
install_requires=[
'click',
'clip-anytorch',
'einops>=0.4',
'einops-exts>=0.0.3',
'embedding-reader',
'kornia>=0.5.4',
'pillow',
'resize-right>=0.0.2',
'torch>=1.10',
'torchvision',
'tqdm',
'vector-quantize-pytorch',
'x-clip>=0.4.4',
'youtokentome',
'webdataset>=0.2.5',
'fsspec>=2022.1.0'
'x-clip>=0.5.1',
'youtokentome'
],
classifiers=[
'Development Status :: 4 - Beta',

View File

@@ -1,291 +0,0 @@
import os
import math
import argparse
import numpy as np
import torch
from torch import nn
from embedding_reader import EmbeddingReader
from dalle2_pytorch import DiffusionPrior, DiffusionPriorNetwork
from dalle2_pytorch.optimizer import get_optimizer
from torch.cuda.amp import autocast,GradScaler
import time
from tqdm import tqdm
import wandb
os.environ["WANDB_SILENT"] = "true"
NUM_TEST_EMBEDDINGS = 100 # for cosine similarity reporting during training
REPORT_METRICS_EVERY = 100 # for cosine similarity and other metric reporting during training
def eval_model(model,device,image_reader,text_reader,start,end,batch_size,loss_type,phase="Validation"):
model.eval()
with torch.no_grad():
total_loss = 0.
total_samples = 0.
for emb_images, emb_text in zip(image_reader(batch_size=batch_size, start=start, end=end),
text_reader(batch_size=batch_size, start=start, end=end)):
emb_images_tensor = torch.tensor(emb_images[0]).to(device)
emb_text_tensor = torch.tensor(emb_text[0]).to(device)
batches = emb_images_tensor.shape[0]
loss = model(text_embed = emb_text_tensor, image_embed = emb_images_tensor)
total_loss += loss.item() * batches
total_samples += batches
avg_loss = (total_loss / total_samples)
wandb.log({f'{phase} {loss_type}': avg_loss})
def save_model(save_path, state_dict):
# Saving State Dict
print("====================================== Saving checkpoint ======================================")
torch.save(state_dict, save_path+'/'+str(time.time())+'_saved_model.pth')
def report_cosine_sims(diffusion_prior,image_reader,text_reader,train_set_size,val_set_size,NUM_TEST_EMBEDDINGS,device):
cos = nn.CosineSimilarity(dim=1, eps=1e-6)
tstart = train_set_size+val_set_size
tend = train_set_size+val_set_size+NUM_TEST_EMBEDDINGS
for embt, embi in zip(text_reader(batch_size = NUM_TEST_EMBEDDINGS, start=tstart, end = tend),image_reader(batch_size = NUM_TEST_EMBEDDINGS, start=tstart, end = tend)):
text_embed = torch.tensor(embt[0]).to(device)
text_embed = text_embed / text_embed.norm(dim=1, keepdim=True)
test_text_cond = dict(text_embed = text_embed)
test_image_embeddings = torch.tensor(embi[0]).to(device)
test_image_embeddings = test_image_embeddings / test_image_embeddings.norm(dim=1, keepdim=True)
predicted_image_embeddings = diffusion_prior.p_sample_loop((NUM_TEST_EMBEDDINGS, 768), text_cond = test_text_cond)
predicted_image_embeddings = predicted_image_embeddings / predicted_image_embeddings.norm(dim=1, keepdim=True)
original_similarity = cos(text_embed,test_image_embeddings).cpu().numpy()
predicted_similarity = cos(text_embed,predicted_image_embeddings).cpu().numpy()
wandb.log({"CosineSimilarity(text_embed,image_embed)": np.mean(original_similarity)})
wandb.log({"CosineSimilarity(text_embed,predicted_image_embed)":np.mean(predicted_similarity)})
return np.mean(predicted_similarity - original_similarity)
def train(image_embed_dim,
image_embed_url,
text_embed_url,
batch_size,
train_percent,
val_percent,
test_percent,
num_epochs,
dp_loss_type,
clip,
dp_condition_on_text_encodings,
dp_timesteps,
dp_l2norm_output,
dp_normformer,
dp_cond_drop_prob,
dpn_depth,
dpn_dim_head,
dpn_heads,
save_interval,
save_path,
device,
learning_rate=0.001,
max_grad_norm=0.5,
weight_decay=0.01,
amp=False):
# DiffusionPriorNetwork
prior_network = DiffusionPriorNetwork(
dim = image_embed_dim,
depth = dpn_depth,
dim_head = dpn_dim_head,
heads = dpn_heads,
normformer = dp_normformer,
l2norm_output = dp_l2norm_output).to(device)
# DiffusionPrior with text embeddings and image embeddings pre-computed
diffusion_prior = DiffusionPrior(
net = prior_network,
clip = clip,
image_embed_dim = image_embed_dim,
timesteps = dp_timesteps,
cond_drop_prob = dp_cond_drop_prob,
loss_type = dp_loss_type,
condition_on_text_encodings = dp_condition_on_text_encodings).to(device)
# Get image and text embeddings from the servers
print("==============Downloading embeddings - image and text====================")
image_reader = EmbeddingReader(embeddings_folder=image_embed_url, file_format="npy")
text_reader = EmbeddingReader(embeddings_folder=text_embed_url, file_format="npy")
num_data_points = text_reader.count
# Create save_path if it doesn't exist
if not os.path.exists(save_path):
os.makedirs(save_path)
### Training code ###
scaler = GradScaler(enabled=amp)
optimizer = get_optimizer(diffusion_prior.net.parameters(), wd=weight_decay, lr=learning_rate)
epochs = num_epochs
step = 0
t = time.time()
train_set_size = int(train_percent*num_data_points)
val_set_size = int(val_percent*num_data_points)
for _ in range(epochs):
diffusion_prior.train()
for emb_images,emb_text in zip(image_reader(batch_size=batch_size, start=0, end=train_set_size),
text_reader(batch_size=batch_size, start=0, end=train_set_size)):
emb_images_tensor = torch.tensor(emb_images[0]).to(device)
emb_text_tensor = torch.tensor(emb_text[0]).to(device)
with autocast(enabled=amp):
loss = diffusion_prior(text_embed = emb_text_tensor,image_embed = emb_images_tensor)
scaler.scale(loss).backward()
# Samples per second
step+=1
samples_per_sec = batch_size*step/(time.time()-t)
# Save checkpoint every save_interval minutes
if(int(time.time()-t) >= 60*save_interval):
t = time.time()
save_model(
save_path,
dict(model=diffusion_prior.state_dict(), optimizer=optimizer.state_dict(), scaler=scaler.state_dict()))
# Log to wandb
wandb.log({"Training loss": loss.item(),
"Steps": step,
"Samples per second": samples_per_sec})
# Log cosineSim(text_embed,predicted_image_embed) - cosineSim(text_embed,image_embed)
# Use NUM_TEST_EMBEDDINGS samples from the test set each time
# Get embeddings from the most recently saved model
if(step % REPORT_METRICS_EVERY) == 0:
diff_cosine_sim = report_cosine_sims(diffusion_prior,
image_reader,
text_reader,
train_set_size,
val_set_size,
NUM_TEST_EMBEDDINGS,
device)
wandb.log({"Cosine similarity difference": diff_cosine_sim})
scaler.unscale_(optimizer)
nn.utils.clip_grad_norm_(diffusion_prior.parameters(), max_grad_norm)
scaler.step(optimizer)
scaler.update()
optimizer.zero_grad()
### Evaluate model(validation run) ###
start = train_set_size
end=start+val_set_size
eval_model(diffusion_prior,device,image_reader,text_reader,start,end,batch_size,dp_loss_type,phase="Validation")
### Test run ###
test_set_size = int(test_percent*train_set_size)
start=train_set_size+val_set_size
end=num_data_points
eval_model(diffusion_prior,device,image_reader,text_reader,start,end,batch_size,dp_loss_type,phase="Test")
def main():
parser = argparse.ArgumentParser()
# Logging
parser.add_argument("--wandb-entity", type=str, default="laion")
parser.add_argument("--wandb-project", type=str, default="diffusion-prior")
parser.add_argument("--wandb-name", type=str, default="laion-dprior")
parser.add_argument("--wandb-dataset", type=str, default="LAION-5B")
parser.add_argument("--wandb-arch", type=str, default="DiffusionPrior")
# URLs for embeddings
parser.add_argument("--image-embed-url", type=str, default="https://mystic.the-eye.eu/public/AI/cah/laion5b/embeddings/laion2B-en/img_emb/")
parser.add_argument("--text-embed-url", type=str, default="https://mystic.the-eye.eu/public/AI/cah/laion5b/embeddings/laion2B-en/text_emb/")
# Hyperparameters
parser.add_argument("--learning-rate", type=float, default=1.1e-4)
parser.add_argument("--weight-decay", type=float, default=6.02e-2)
parser.add_argument("--max-grad-norm", type=float, default=0.5)
parser.add_argument("--batch-size", type=int, default=10**4)
parser.add_argument("--num-epochs", type=int, default=5)
# Image embed dimension
parser.add_argument("--image-embed-dim", type=int, default=768)
# Train-test split
parser.add_argument("--train-percent", type=float, default=0.7)
parser.add_argument("--val-percent", type=float, default=0.2)
parser.add_argument("--test-percent", type=float, default=0.1)
# LAION training(pre-computed embeddings)
# DiffusionPriorNetwork(dpn) parameters
parser.add_argument("--dpn-depth", type=int, default=6)
parser.add_argument("--dpn-dim-head", type=int, default=64)
parser.add_argument("--dpn-heads", type=int, default=8)
# DiffusionPrior(dp) parameters
parser.add_argument("--dp-condition-on-text-encodings", type=bool, default=False)
parser.add_argument("--dp-timesteps", type=int, default=100)
parser.add_argument("--dp-l2norm-output", type=bool, default=False)
parser.add_argument("--dp-normformer", type=bool, default=False)
parser.add_argument("--dp-cond-drop-prob", type=float, default=0.1)
parser.add_argument("--dp-loss-type", type=str, default="l2")
parser.add_argument("--clip", type=str, default=None)
parser.add_argument("--amp", type=bool, default=False)
# Model checkpointing interval(minutes)
parser.add_argument("--save-interval", type=int, default=30)
parser.add_argument("--save-path", type=str, default="./diffusion_prior_checkpoints")
args = parser.parse_args()
print("Setting up wandb logging... Please wait...")
wandb.init(
entity=args.wandb_entity,
project=args.wandb_project,
config={
"learning_rate": args.learning_rate,
"architecture": args.wandb_arch,
"dataset": args.wandb_dataset,
"epochs": args.num_epochs,
})
print("wandb logging setup done!")
# Obtain the utilized device.
has_cuda = torch.cuda.is_available()
if has_cuda:
device = torch.device("cuda:0")
torch.cuda.set_device(device)
# Training loop
train(args.image_embed_dim,
args.image_embed_url,
args.text_embed_url,
args.batch_size,
args.train_percent,
args.val_percent,
args.test_percent,
args.num_epochs,
args.dp_loss_type,
args.clip,
args.dp_condition_on_text_encodings,
args.dp_timesteps,
args.dp_l2norm_output,
args.dp_normformer,
args.dp_cond_drop_prob,
args.dpn_depth,
args.dpn_dim_head,
args.dpn_heads,
args.save_interval,
args.save_path,
device,
args.learning_rate,
args.max_grad_norm,
args.weight_decay,
args.amp)
if __name__ == "__main__":
main()