Implementação do Classifier Free Guidance em Pytorch, com ênfase no condicionamento de texto e flexibilidade para incluir vários modelos de incorporação de texto, como feito no eDiff-I
Está claro agora que a orientação por texto é a interface definitiva para os modelos. Este repositório aproveitará um pouco da magia do decorador python para facilitar a incorporação do condicionamento de texto SOTA em qualquer modelo.
StabilityAI pelo patrocínio generoso, assim como meus outros patrocinadores por aí
? Huggingface por sua incrível biblioteca de transformadores. O módulo de condicionamento de texto usará embeddings T5, conforme recomendam as pesquisas mais recentes
OpenCLIP para fornecer modelos CLIP de código aberto SOTA. O modelo eDiff apresenta imensas melhorias ao combinar os embeddings T5 com os embeddings de texto CLIP
$ pip install classifier-free-guidance-pytorch
import torch
from classifier_free_guidance_pytorch import TextConditioner
text_conditioner = TextConditioner (
model_types = 't5' ,
hidden_dims = ( 256 , 512 ),
hiddens_channel_first = False ,
cond_drop_prob = 0.2 # conditional dropout 20% of the time, must be greater than 0. to unlock classifier free guidance
). cuda ()
# pass in your text as a List[str], and get back a List[callable]
# each callable function receives the hiddens in the dimensions listed at init (hidden_dims)
first_condition_fn , second_condition_fn = text_conditioner ([ 'a dog chasing after a ball' ])
# these hiddens will be in the direct flow of your model, say in a unet
first_hidden = torch . randn ( 1 , 16 , 256 ). cuda ()
second_hidden = torch . randn ( 1 , 32 , 512 ). cuda ()
# conditioned features
first_conditioned = first_condition_fn ( first_hidden )
second_conditioned = second_condition_fn ( second_hidden )
Se você deseja usar o condicionamento baseado em atenção cruzada (cada recurso oculto em sua rede pode atender a tokens de subpalavras individuais), basta importar o AttentionTextConditioner
. O resto é o mesmo
from classifier_free_guidance_pytorch import AttentionTextConditioner
text_conditioner = AttentionTextConditioner (
model_types = ( 't5' , 'clip' ), # something like in eDiff paper, where they used both T5 and Clip for even better results (Balaji et al.)
hidden_dims = ( 256 , 512 ),
cond_drop_prob = 0.2
)
Este é um trabalho em andamento para facilitar ao máximo o condicionamento de texto da sua rede.
Primeiro, digamos que você tenha uma rede simples de duas camadas
import torch
from torch import nn
class MLP ( nn . Module ):
def __init__ (
self ,
dim
):
super (). __init__ ()
self . proj_in = nn . Sequential ( nn . Linear ( dim , dim * 2 ), nn . ReLU ())
self . proj_mid = nn . Sequential ( nn . Linear ( dim * 2 , dim ), nn . ReLU ())
self . proj_out = nn . Linear ( dim , 1 )
def forward (
self ,
data
):
hiddens1 = self . proj_in ( data )
hiddens2 = self . proj_mid ( hiddens1 )
return self . proj_out ( hiddens2 )
# instantiate model and pass in some data, get (in this case) a binary prediction
model = MLP ( dim = 256 )
data = torch . randn ( 2 , 256 )
pred = model ( data )
Você gostaria de condicionar as camadas ocultas ( hiddens1
e hiddens2
) com texto. Cada elemento de lote aqui teria seu próprio condicionamento de texto livre
Isso foi reduzido para cerca de 3 etapas usando este repositório.
import torch
from torch import nn
from classifier_free_guidance_pytorch import classifier_free_guidance_class_decorator
@ classifier_free_guidance_class_decorator
class MLP ( nn . Module ):
def __init__ ( self , dim ):
super (). __init__ ()
self . proj_in = nn . Sequential ( nn . Linear ( dim , dim * 2 ), nn . ReLU ())
self . proj_mid = nn . Sequential ( nn . Linear ( dim * 2 , dim ), nn . ReLU ())
self . proj_out = nn . Linear ( dim , 1 )
def forward (
self ,
inp ,
cond_fns # List[Callable] - (1) your forward function now receives a list of conditioning functions, which you invoke on your hidden tensors
):
cond_hidden1 , cond_hidden2 = cond_fns # conditioning functions are given back in the order of the `hidden_dims` set on the text conditioner
hiddens1 = self . proj_in ( inp )
hiddens1 = cond_hidden1 ( hiddens1 ) # (2) condition the first hidden layer with FiLM
hiddens2 = self . proj_mid ( hiddens1 )
hiddens2 = cond_hidden2 ( hiddens2 ) # condition the second hidden layer with FiLM
return self . proj_out ( hiddens2 )
# instantiate your model - extra keyword arguments will need to be defined, prepended by `text_condition_`
model = MLP (
dim = 256 ,
text_condition_type = 'film' , # can be film, attention, or null (none)
text_condition_model_types = ( 't5' , 'clip' ), # in this example, conditioning on both T5 and OpenCLIP
text_condition_hidden_dims = ( 512 , 256 ), # and pass in the hidden dimensions you would like to condition on. in this case there are two hidden dimensions (dim * 2 and dim, after the first and second projections)
text_condition_cond_drop_prob = 0.25 # conditional dropout probability for classifier free guidance. can be set to 0. if you do not need it and just want the text conditioning
)
# now you have your input data as well as corresponding free text as List[str]
data = torch . randn ( 2 , 256 )
texts = [ 'a description' , 'another description' ]
# (3) train your model, passing in your list of strings as 'texts'
pred = model ( data , texts = texts )
# after much training, you can now do classifier free guidance by passing in a condition scale of > 1. !
model . eval ()
guided_pred = model ( data , texts = texts , cond_scale = 3. , remove_parallel_component = True ) # cond_scale stands for conditioning scale from classifier free guidance paper
condicionamento completo do filme, sem orientação gratuita do classificador (usado aqui)
adicionar guia gratuito de classificador para condicionamento de filme
condicionamento completo de atenção cruzada
teste de estresse para unet espaço-tempo em make-a-video
@article { Ho2022ClassifierFreeDG ,
title = { Classifier-Free Diffusion Guidance } ,
author = { Jonathan Ho } ,
journal = { ArXiv } ,
year = { 2022 } ,
volume = { abs/2207.12598 }
}
@article { Balaji2022eDiffITD ,
title = { eDiff-I: Text-to-Image Diffusion Models with an Ensemble of Expert Denoisers } ,
author = { Yogesh Balaji and Seungjun Nah and Xun Huang and Arash Vahdat and Jiaming Song and Karsten Kreis and Miika Aittala and Timo Aila and Samuli Laine and Bryan Catanzaro and Tero Karras and Ming-Yu Liu } ,
journal = { ArXiv } ,
year = { 2022 } ,
volume = { abs/2211.01324 }
}
@inproceedings { dao2022flashattention ,
title = { Flash{A}ttention: Fast and Memory-Efficient Exact Attention with {IO}-Awareness } ,
author = { Dao, Tri and Fu, Daniel Y. and Ermon, Stefano and Rudra, Atri and R{'e}, Christopher } ,
booktitle = { Advances in Neural Information Processing Systems } ,
year = { 2022 }
}
@inproceedings { Lin2023CommonDN ,
title = { Common Diffusion Noise Schedules and Sample Steps are Flawed } ,
author = { Shanchuan Lin and Bingchen Liu and Jiashi Li and Xiao Yang } ,
year = { 2023 }
}
@inproceedings { Chung2024CFGMC ,
title = { CFG++: Manifold-constrained Classifier Free Guidance for Diffusion Models } ,
author = { Hyungjin Chung and Jeongsol Kim and Geon Yeong Park and Hyelin Nam and Jong Chul Ye } ,
year = { 2024 } ,
url = { https://api.semanticscholar.org/CorpusID:270391454 }
}
@inproceedings { Sadat2024EliminatingOA ,
title = { Eliminating Oversaturation and Artifacts of High Guidance Scales in Diffusion Models } ,
author = { Seyedmorteza Sadat and Otmar Hilliges and Romann M. Weber } ,
year = { 2024 } ,
url = { https://api.semanticscholar.org/CorpusID:273098845 }
}