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README.md
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@@ -1,10 +1,8 @@
<img src="./dalle2.png" width="450px"></img>
## DALL-E 2 - Pytorch
## DALL-E 2 - Pytorch (wip)
Implementation of <a href="https://openai.com/dall-e-2/">DALL-E 2</a>, OpenAI's updated text-to-image synthesis neural network, in Pytorch.
<a href="https://youtu.be/RJwPN4qNi_Y?t=555">Yannic Kilcher summary</a> | <a href="https://www.youtube.com/watch?v=F1X4fHzF4mQ">AssemblyAI explainer</a>
Implementation of <a href="https://openai.com/dall-e-2/">DALL-E 2</a>, OpenAI's updated text-to-image synthesis neural network, in Pytorch. <a href="https://youtu.be/RJwPN4qNi_Y?t=555">Yannic Kilcher summary</a>
The main novelty seems to be an extra layer of indirection with the prior network (whether it is an autoregressive transformer or a diffusion network), which predicts an image embedding based on the text embedding from CLIP. Specifically, this repository will only build out the diffusion prior network, as it is the best performing variant (but which incidentally involves a causal transformer as the denoising network 😂)
@@ -14,7 +12,9 @@ It may also explore an extension of using <a href="https://huggingface.co/spaces
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 Jax version. It will be completed after the Pytorch version shows signs of life on my toy tasks. <a href="https://github.com/lucidrains/dalle2-jax">Placeholder repository</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.
Do let me know if anyone is interested in a Jax version https://github.com/lucidrains/DALLE2-pytorch/discussions/8
For all of you emailing me (there is a lot), the best way to contribute is through pull requests. Everything is open sourced after all. All my thoughts are public. This is your moment to participate.
## Install
@@ -22,11 +22,19 @@ There was enough interest for a Jax version. It will be completed after the Pyto
$ pip install dalle2-pytorch
```
## Usage
## CLI Usage (work in progress)
```bash
$ dream 'sharing a sunset at the summit of mount everest with my dog'
```
Once built, images will be saved to the same directory the command is invoked
## Training (for deep learning practitioners)
To train DALLE-2 is a 3 step process, with the training of CLIP being the most important
To train CLIP, you can either use <a href="https://github.com/lucidrains/x-clip">x-clip</a> package, or join the LAION discord, where a lot of replication efforts are already <a href="https://github.com/mlfoundations/open_clip">underway</a>.
To train CLIP, you can either use `x-clip` package, or join the LAION discord, where a lot of replication efforts are already underway.
This repository will demonstrate integration with `x-clip` for starters
@@ -101,7 +109,7 @@ clip = CLIP(
unet = Unet(
dim = 128,
image_embed_dim = 512,
cond_dim = 128,
time_dim = 128,
channels = 3,
dim_mults=(1, 2, 4, 8)
).cuda()
@@ -109,7 +117,7 @@ unet = Unet(
# decoder, which contains the unet and clip
decoder = Decoder(
unet = unet,
net = unet,
clip = clip,
timesteps = 100,
cond_drop_prob = 0.2
@@ -128,14 +136,12 @@ loss.backward()
# then it will learn to generate images based on the CLIP image embeddings
```
Finally, the main contribution of the paper. The repository offers the diffusion prior network. It takes the CLIP text embeddings and tries to generate the CLIP image embeddings. Again, you will need the trained CLIP from the first step
Finally, the main contribution of the paper. The repository offers the diffusion prior network. It takes the CLIP text embeddings and tries to generate the CLIP image embeddings. Again, you will need the trained CLIP fron the first step
```python
import torch
from dalle2_pytorch import DiffusionPriorNetwork, DiffusionPrior, CLIP
# get trained CLIP from step one
clip = CLIP(
dim_text = 512,
dim_image = 512,
@@ -154,6 +160,7 @@ clip = CLIP(
prior_network = DiffusionPriorNetwork(
dim = 512,
num_timesteps = 100,
depth = 6,
dim_head = 64,
heads = 8
@@ -182,82 +189,7 @@ loss.backward()
# now the diffusion prior can generate image embeddings from the text embeddings
```
In the paper, they actually used a <a href="https://cascaded-diffusion.github.io/">recently discovered technique</a>, from <a href="http://www.jonathanho.me/">Jonathan Ho</a> himself (original author of DDPMs, the core technique used in DALL-E v2) for high resolution image synthesis.
This can easily be used within this framework as so
```python
import torch
from dalle2_pytorch import Unet, Decoder, CLIP
# trained clip from step 1
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()
# 2 unets for the decoder (a la cascading DDPM)
unet1 = Unet(
dim = 32,
image_embed_dim = 512,
cond_dim = 128,
channels = 3,
dim_mults = (1, 2, 4, 8)
).cuda()
unet2 = Unet(
dim = 32,
image_embed_dim = 512,
cond_dim = 128,
channels = 3,
dim_mults = (1, 2, 4, 8, 16)
).cuda()
# decoder, which contains the unet(s) and clip
decoder = Decoder(
clip = clip,
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,
cond_drop_prob = 0.2
).cuda()
# mock images (get a lot of this)
images = torch.randn(4, 3, 512, 512).cuda()
# feed images into decoder, specifying which unet you want to train
# each unet can be trained separately, which is one of the benefits of the cascading DDPM scheme
loss = decoder(images, unet_number = 1)
loss.backward()
loss = decoder(images, unet_number = 2)
loss.backward()
# do the above for many steps for both unets
# then it will learn to generate images based on the CLIP image embeddings
# chaining the unets from lowest resolution to highest resolution (thus cascading)
mock_image_embed = torch.randn(1, 512).cuda()
images = decoder.sample(mock_image_embed) # (1, 3, 512, 512)
```
Finally, to generate the DALL-E2 images from text. Insert the trained `DiffusionPrior` as well as the `Decoder` (which wraps `CLIP`, the causal transformer, and unet(s))
Finally, to generate the DALL-E2 images from text. Insert the trained `DiffusionPrior` as well as the `Decoder` (which both contains `CLIP`, a unet, and a causal transformer)
```python
from dalle2_pytorch import DALLE2
@@ -267,7 +199,7 @@ dalle2 = DALLE2(
decoder = decoder
)
# send the text as a string if you want to use the simple tokenizer from DALLE v1
# send the text as a string if you want to use the simple tokenizer from DALL-E1
# or you can do it as token ids, if you have your own tokenizer
texts = ['glistening morning dew on a flower petal']
@@ -280,7 +212,10 @@ Let's see the whole script below
```python
import torch
from dalle2_pytorch import DALLE2, DiffusionPriorNetwork, DiffusionPrior, Unet, Decoder, CLIP
from dalle2_pytorch.dalle2_pytorch import DALLE2
from dalle2_pytorch import DiffusionPriorNetwork, DiffusionPrior, Unet, Decoder, CLIP
import torch
clip = CLIP(
dim_text = 512,
@@ -317,6 +252,7 @@ loss.backward()
prior_network = DiffusionPriorNetwork(
dim = 512,
num_timesteps = 100,
depth = 6,
dim_head = 64,
heads = 8
@@ -336,33 +272,23 @@ loss.backward()
# decoder (with unet)
unet1 = Unet(
unet = Unet(
dim = 128,
image_embed_dim = 512,
cond_dim = 128,
time_dim = 128,
channels = 3,
dim_mults=(1, 2, 4, 8)
).cuda()
unet2 = Unet(
dim = 16,
image_embed_dim = 512,
cond_dim = 128,
channels = 3,
dim_mults = (1, 2, 4, 8, 16)
).cuda()
decoder = Decoder(
unet = (unet1, unet2),
image_sizes = (128, 256),
net = unet,
clip = clip,
timesteps = 100,
cond_drop_prob = 0.2
).cuda()
for unet_number in (1, 2):
loss = decoder(images, unet_number = unet_number) # this can optionally be decoder(images, text) if you wish to condition on the text encodings as well, though it was hinted in the paper it didn't do much
loss.backward()
loss = decoder(images)
loss.backward()
# do above for many steps
@@ -371,32 +297,13 @@ dalle2 = DALLE2(
decoder = decoder
)
images = dalle2(
['cute puppy chasing after a squirrel'],
cond_scale = 2. # classifier free guidance strength (> 1 would strengthen the condition)
)
images = dalle2(['cute puppy chasing after a squirrel'])
# save your image (in this example, of size 256x256)
# save your image
```
Everything in this readme should run without error
You can also train the decoder on images of greater than the size (say 512x512) at which CLIP was trained (256x256). The images will be resized to CLIP image resolution for the image embeddings
For the layperson, no worries, training will all be automated into a CLI tool, at least for small scale training.
## CLI Usage (work in progress)
```bash
$ dream 'sharing a sunset at the summit of mount everest with my dog'
```
Once built, images will be saved to the same directory the command is invoked
## Training wrapper (wip)
Offer training wrappers
## Training CLI (wip)
<a href="https://github.com/lucidrains/stylegan2-pytorch">template</a>
@@ -406,17 +313,11 @@ Offer training wrappers
- [x] finish off gaussian diffusion class for latent embedding - allow for prediction of epsilon
- [x] add what was proposed in the paper, where DDPM objective for image latent embedding predicts x0 directly (reread vq-diffusion paper and get caught up on that line of work)
- [x] make sure it works end to end to produce an output tensor, taking a single gradient step
- [x] augment unet so that it can also be conditioned on text encodings (although in paper they hinted this didn't make much a difference)
- [x] figure out all the current bag of tricks needed to make DDPMs great (starting with the blur trick mentioned in paper)
- [x] build the cascading ddpm by having Decoder class manage multiple unets at different resolutions
- [x] add efficient attention in unet
- [x] be able to finely customize what to condition on (text, image embed) for specific unet in the cascade (super resolution ddpms near the end may not need too much conditioning)
- [x] offload unets not being trained on to CPU for memory efficiency (for training each resolution unets separately)
- [ ] build out latent diffusion architecture, with the vq-reg variant (vqgan-vae), make it completely optional
- [ ] 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
- [ ] augment unet so that it can also be conditioned on text encodings (although in paper they hinted this didn't make much a difference)
- [ ] look into Jonathan Ho's cascading DDPM for the decoder, as that seems to be what they are using. get caught up on DDPM literature
- [ ] figure out all the current bag of tricks needed to make DDPMs great (starting with the blur trick mentioned in paper)
- [ ] train on a toy task, offer in colab
- [ ] extend diffusion head to use diffusion-gan (potentially using lightweight-gan) to speed up inference
- [ ] add attention to unet - apply some personal tricks with efficient attention
## Citations
@@ -464,13 +365,3 @@ Offer training wrappers
primaryClass = {cs.LG}
}
```
```bibtex
@inproceedings{Tu2022MaxViTMV,
title = {MaxViT: Multi-Axis Vision Transformer},
author = {Zhe-Wei Tu and Hossein Talebi and Han Zhang and Feng Yang and Peyman Milanfar and Alan Conrad Bovik and Yinxiao Li},
year = {2022}
}
```
*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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@@ -1,4 +1,2 @@
from dalle2_pytorch.dalle2_pytorch import DALLE2, DiffusionPriorNetwork, DiffusionPrior, Unet, Decoder
from dalle2_pytorch.vqgan_vae import VQGanVAE
from x_clip import CLIP

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@@ -6,4 +6,4 @@ def main():
@click.command()
@click.argument('text')
def dream(text):
return 'not ready yet'
return image

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@@ -1,532 +0,0 @@
import copy
import math
from math import sqrt
from functools import partial, wraps
from vector_quantize_pytorch import VectorQuantize as VQ
import torch
from torch import nn, einsum
import torch.nn.functional as F
from torch.autograd import grad as torch_grad
import torchvision
from einops import rearrange, reduce, repeat
# constants
MList = nn.ModuleList
# helper functions
def exists(val):
return val is not None
def default(val, d):
return val if exists(val) else d
# decorators
def eval_decorator(fn):
def inner(model, *args, **kwargs):
was_training = model.training
model.eval()
out = fn(model, *args, **kwargs)
model.train(was_training)
return out
return inner
def remove_vgg(fn):
@wraps(fn)
def inner(self, *args, **kwargs):
has_vgg = hasattr(self, 'vgg')
if has_vgg:
vgg = self.vgg
delattr(self, 'vgg')
out = fn(self, *args, **kwargs)
if has_vgg:
self.vgg = vgg
return out
return inner
# keyword argument helpers
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
# tensor helper functions
def log(t, eps = 1e-10):
return torch.log(t + eps)
def gradient_penalty(images, output, weight = 10):
batch_size = images.shape[0]
gradients = torch_grad(outputs = output, inputs = images,
grad_outputs = torch.ones(output.size(), device = images.device),
create_graph = True, retain_graph = True, only_inputs = True)[0]
gradients = rearrange(gradients, 'b ... -> b (...)')
return weight * ((gradients.norm(2, dim = 1) - 1) ** 2).mean()
def l2norm(t):
return F.normalize(t, dim = -1)
def leaky_relu(p = 0.1):
return nn.LeakyReLU(0.1)
def stable_softmax(t, dim = -1, alpha = 32 ** 2):
t = t / alpha
t = t - torch.amax(t, dim = dim, keepdim = True).detach()
return (t * alpha).softmax(dim = dim)
def safe_div(numer, denom, eps = 1e-8):
return numer / (denom + eps)
# gan losses
def hinge_discr_loss(fake, real):
return (F.relu(1 + fake) + F.relu(1 - real)).mean()
def hinge_gen_loss(fake):
return -fake.mean()
def bce_discr_loss(fake, real):
return (-log(1 - torch.sigmoid(fake)) - log(torch.sigmoid(real))).mean()
def bce_gen_loss(fake):
return -log(torch.sigmoid(fake)).mean()
def grad_layer_wrt_loss(loss, layer):
return torch_grad(
outputs = loss,
inputs = layer,
grad_outputs = torch.ones_like(loss),
retain_graph = True
)[0].detach()
# vqgan vae
class LayerNormChan(nn.Module):
def __init__(
self,
dim,
eps = 1e-5
):
super().__init__()
self.eps = eps
self.gamma = nn.Parameter(torch.ones(1, dim, 1, 1))
def forward(self, x):
var = torch.var(x, dim = 1, unbiased = False, keepdim = True)
mean = torch.mean(x, dim = 1, keepdim = True)
return (x - mean) / (var + self.eps).sqrt() * self.gamma
class Discriminator(nn.Module):
def __init__(
self,
dims,
channels = 3,
groups = 16,
init_kernel_size = 5
):
super().__init__()
dim_pairs = zip(dims[:-1], dims[1:])
self.layers = MList([nn.Sequential(nn.Conv2d(channels, dims[0], init_kernel_size, padding = init_kernel_size // 2), leaky_relu())])
for dim_in, dim_out in dim_pairs:
self.layers.append(nn.Sequential(
nn.Conv2d(dim_in, dim_out, 4, stride = 2, padding = 1),
nn.GroupNorm(groups, dim_out),
leaky_relu()
))
dim = dims[-1]
self.to_logits = nn.Sequential( # return 5 x 5, for PatchGAN-esque training
nn.Conv2d(dim, dim, 1),
leaky_relu(),
nn.Conv2d(dim, 1, 4)
)
def forward(self, x):
for net in self.layers:
x = net(x)
return self.to_logits(x)
class ContinuousPositionBias(nn.Module):
""" from https://arxiv.org/abs/2111.09883 """
def __init__(self, *, dim, heads, layers = 2):
super().__init__()
self.net = MList([])
self.net.append(nn.Sequential(nn.Linear(2, dim), leaky_relu()))
for _ in range(layers - 1):
self.net.append(nn.Sequential(nn.Linear(dim, dim), leaky_relu()))
self.net.append(nn.Linear(dim, heads))
self.register_buffer('rel_pos', None, persistent = False)
def forward(self, x):
n, device = x.shape[-1], x.device
fmap_size = int(sqrt(n))
if not exists(self.rel_pos):
pos = torch.arange(fmap_size, device = device)
grid = torch.stack(torch.meshgrid(pos, pos, indexing = 'ij'))
grid = rearrange(grid, 'c i j -> (i j) c')
rel_pos = rearrange(grid, 'i c -> i 1 c') - rearrange(grid, 'j c -> 1 j c')
rel_pos = torch.sign(rel_pos) * torch.log(rel_pos.abs() + 1)
self.register_buffer('rel_pos', rel_pos, persistent = False)
rel_pos = self.rel_pos.float()
for layer in self.net:
rel_pos = layer(rel_pos)
bias = rearrange(rel_pos, 'i j h -> h i j')
return x + bias
class GLUResBlock(nn.Module):
def __init__(self, chan, groups = 16):
super().__init__()
self.net = nn.Sequential(
nn.Conv2d(chan, chan * 2, 3, padding = 1),
nn.GLU(dim = 1),
nn.GroupNorm(groups, chan),
nn.Conv2d(chan, chan * 2, 3, padding = 1),
nn.GLU(dim = 1),
nn.GroupNorm(groups, chan),
nn.Conv2d(chan, chan, 1)
)
def forward(self, x):
return self.net(x) + x
class ResBlock(nn.Module):
def __init__(self, chan, groups = 16):
super().__init__()
self.net = nn.Sequential(
nn.Conv2d(chan, chan, 3, padding = 1),
nn.GroupNorm(groups, chan),
leaky_relu(),
nn.Conv2d(chan, chan, 3, padding = 1),
nn.GroupNorm(groups, chan),
leaky_relu(),
nn.Conv2d(chan, chan, 1)
)
def forward(self, x):
return self.net(x) + x
class VQGanAttention(nn.Module):
def __init__(
self,
*,
dim,
dim_head = 64,
heads = 8,
dropout = 0.
):
super().__init__()
self.heads = heads
self.scale = dim_head ** -0.5
inner_dim = heads * dim_head
self.dropout = nn.Dropout(dropout)
self.pre_norm = LayerNormChan(dim)
self.cpb = ContinuousPositionBias(dim = dim // 4, heads = heads)
self.to_qkv = nn.Conv2d(dim, inner_dim * 3, 1, bias = False)
self.to_out = nn.Conv2d(inner_dim, dim, 1, bias = False)
def forward(self, x):
h = self.heads
height, width, residual = *x.shape[-2:], x.clone()
x = self.pre_norm(x)
q, k, v = self.to_qkv(x).chunk(3, dim = 1)
q, k, v = map(lambda t: rearrange(t, 'b (h c) x y -> b h c (x y)', h = h), (q, k, v))
sim = einsum('b h c i, b h c j -> b h i j', q, k) * self.scale
sim = self.cpb(sim)
attn = stable_softmax(sim, dim = -1)
attn = self.dropout(attn)
out = einsum('b h i j, b h c j -> b h c i', attn, v)
out = rearrange(out, 'b h c (x y) -> b (h c) x y', x = height, y = width)
out = self.to_out(out)
return out + residual
class VQGanVAE(nn.Module):
def __init__(
self,
*,
dim,
image_size,
channels = 3,
num_layers = 4,
layer_mults = None,
l2_recon_loss = False,
use_hinge_loss = True,
num_resnet_blocks = 1,
vgg = None,
vq_codebook_size = 512,
vq_decay = 0.8,
vq_commitment_weight = 1.,
vq_kmeans_init = True,
vq_use_cosine_sim = True,
use_attn = True,
attn_dim_head = 64,
attn_heads = 8,
resnet_groups = 16,
attn_dropout = 0.,
first_conv_kernel_size = 5,
use_vgg_and_gan = True,
**kwargs
):
super().__init__()
assert dim % resnet_groups == 0, f'dimension {dim} must be divisible by {resnet_groups} (groups for the groupnorm)'
vq_kwargs, kwargs = groupby_prefix_and_trim('vq_', kwargs)
self.image_size = image_size
self.channels = channels
self.num_layers = num_layers
self.fmap_size = image_size // (num_layers ** 2)
self.codebook_size = vq_codebook_size
self.encoders = MList([])
self.decoders = MList([])
layer_mults = default(layer_mults, list(map(lambda t: 2 ** t, range(num_layers))))
assert len(layer_mults) == num_layers, 'layer multipliers must be equal to designated number of layers'
layer_dims = [dim * mult for mult in layer_mults]
dims = (dim, *layer_dims)
codebook_dim = layer_dims[-1]
dim_pairs = zip(dims[:-1], dims[1:])
append = lambda arr, t: arr.append(t)
prepend = lambda arr, t: arr.insert(0, t)
if not isinstance(num_resnet_blocks, tuple):
num_resnet_blocks = (*((0,) * (num_layers - 1)), num_resnet_blocks)
if not isinstance(use_attn, tuple):
use_attn = (*((False,) * (num_layers - 1)), use_attn)
assert len(num_resnet_blocks) == num_layers, 'number of resnet blocks config must be equal to number of layers'
assert len(use_attn) == num_layers
for layer_index, (dim_in, dim_out), layer_num_resnet_blocks, layer_use_attn in zip(range(num_layers), dim_pairs, num_resnet_blocks, use_attn):
append(self.encoders, nn.Sequential(nn.Conv2d(dim_in, dim_out, 4, stride = 2, padding = 1), leaky_relu()))
prepend(self.decoders, nn.Sequential(nn.Upsample(scale_factor = 2, mode = 'bilinear', align_corners = False), nn.Conv2d(dim_out, dim_in, 3, padding = 1), leaky_relu()))
if layer_use_attn:
prepend(self.decoders, VQGanAttention(dim = dim_out, heads = attn_heads, dim_head = attn_dim_head, dropout = attn_dropout))
for _ in range(layer_num_resnet_blocks):
append(self.encoders, ResBlock(dim_out, groups = resnet_groups))
prepend(self.decoders, GLUResBlock(dim_out, groups = resnet_groups))
if layer_use_attn:
append(self.encoders, VQGanAttention(dim = dim_out, heads = attn_heads, dim_head = attn_dim_head, dropout = attn_dropout))
prepend(self.encoders, nn.Conv2d(channels, dim, first_conv_kernel_size, padding = first_conv_kernel_size // 2))
append(self.decoders, nn.Conv2d(dim, channels, 1))
self.vq = VQ(
dim = codebook_dim,
codebook_size = vq_codebook_size,
decay = vq_decay,
commitment_weight = vq_commitment_weight,
accept_image_fmap = True,
kmeans_init = vq_kmeans_init,
use_cosine_sim = vq_use_cosine_sim,
**vq_kwargs
)
# reconstruction loss
self.recon_loss_fn = F.mse_loss if l2_recon_loss else F.l1_loss
# turn off GAN and perceptual loss if grayscale
self.vgg = None
self.discr = None
self.use_vgg_and_gan = use_vgg_and_gan
if not use_vgg_and_gan:
return
# preceptual loss
if exists(vgg):
self.vgg = vgg
else:
self.vgg = torchvision.models.vgg16(pretrained = True)
self.vgg.classifier = nn.Sequential(*self.vgg.classifier[:-2])
# gan related losses
self.discr = Discriminator(dims = dims, channels = channels)
self.discr_loss = hinge_discr_loss if use_hinge_loss else bce_discr_loss
self.gen_loss = hinge_gen_loss if use_hinge_loss else bce_gen_loss
def copy_for_eval(self):
device = next(self.parameters()).device
vae_copy = copy.deepcopy(self.cpu())
if vae_copy.use_vgg_and_gan:
del vae_copy.discr
del vae_copy.vgg
vae_copy.eval()
return vae_copy.to(device)
@remove_vgg
def state_dict(self, *args, **kwargs):
return super().state_dict(*args, **kwargs)
@remove_vgg
def load_state_dict(self, *args, **kwargs):
return super().load_state_dict(*args, **kwargs)
@property
def codebook(self):
return self.vq.codebook
def encode(self, fmap):
for enc in self.encoders:
fmap = enc(fmap)
return fmap
def decode(self, fmap):
fmap, indices, commit_loss = self.vq(fmap)
for dec in self.decoders:
fmap = dec(fmap)
return fmap, indices, commit_loss
def forward(
self,
img,
return_loss = False,
return_discr_loss = False,
return_recons = False
):
batch, channels, height, width, device = *img.shape, img.device
assert height == self.image_size and width == self.image_size, 'height and width of input image must be equal to {self.image_size}'
assert channels == self.channels, 'number of channels on image or sketch is not equal to the channels set on this VQGanVAE'
fmap = self.encode(img)
fmap, indices, commit_loss = self.decode(fmap)
if not return_loss and not return_discr_loss:
return fmap
assert return_loss ^ return_discr_loss, 'you should either return autoencoder loss or discriminator loss, but not both'
# whether to return discriminator loss
if return_discr_loss:
assert exists(self.discr), 'discriminator must exist to train it'
fmap.detach_()
img.requires_grad_()
fmap_discr_logits, img_discr_logits = map(self.discr, (fmap, img))
gp = gradient_penalty(img, img_discr_logits)
discr_loss = self.discr_loss(fmap_discr_logits, img_discr_logits)
loss = discr_loss + gp
if return_recons:
return loss, fmap
return loss
# reconstruction loss
recon_loss = self.recon_loss_fn(fmap, img)
# early return if training on grayscale
if not self.use_vgg_and_gan:
if return_recons:
return recon_loss, fmap
return recon_loss
# perceptual loss
img_vgg_input = img
fmap_vgg_input = fmap
if img.shape[1] == 1:
# handle grayscale for vgg
img_vgg_input, fmap_vgg_input = map(lambda t: repeat(t, 'b 1 ... -> b c ...', c = 3), (img_vgg_input, fmap_vgg_input))
img_vgg_feats = self.vgg(img_vgg_input)
recon_vgg_feats = self.vgg(fmap_vgg_input)
perceptual_loss = F.mse_loss(img_vgg_feats, recon_vgg_feats)
# generator loss
gen_loss = self.gen_loss(self.discr(fmap))
# calculate adaptive weight
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)
adaptive_weight = safe_div(norm_grad_wrt_perceptual_loss, norm_grad_wrt_gen_loss)
adaptive_weight.clamp_(max = 1e4)
# combine losses
loss = recon_loss + perceptual_loss + commit_loss + adaptive_weight * gen_loss
if return_recons:
return loss, fmap
return loss

View File

@@ -10,7 +10,7 @@ setup(
'dream = dalle2_pytorch.cli:dream'
],
},
version = '0.0.36',
version = '0.0.4',
license='MIT',
description = 'DALL-E 2',
author = 'Phil Wang',
@@ -25,12 +25,10 @@ setup(
'click',
'einops>=0.4',
'einops-exts>=0.0.3',
'kornia>=0.5.4',
'pillow',
'torch>=1.10',
'torchvision',
'tqdm',
'vector-quantize-pytorch',
'x-clip>=0.4.4',
'youtokentome'
],