Implementación de Classifier Free Guidance en Pytorch, con énfasis en el acondicionamiento de texto y flexibilidad para incluir múltiples modelos de incrustación de texto, como se hace en eDiff-I
Ahora está claro que la guía textual es la interfaz definitiva para los modelos. Este repositorio aprovechará algo de la magia del decorador de Python para facilitar la incorporación del acondicionamiento de texto SOTA a cualquier modelo.
StabilityAI por el generoso patrocinio, así como a mis otros patrocinadores.
? Huggingface por su increíble biblioteca de transformadores. El módulo de acondicionamiento de texto utilizará incrustaciones T5, como recomiendan las últimas investigaciones
OpenCLIP para proporcionar modelos CLIP de código abierto SOTA. El modelo eDiff ve inmensas mejoras al combinar las incrustaciones T5 con incrustaciones 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 )
Si desea utilizar el condicionamiento basado en atención cruzada (cada función oculta en su red puede atender tokens de subpalabras individuales), simplemente importe AttentionTextConditioner
en su lugar. el resto es igual
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 es un trabajo en progreso para hacer lo más fácil posible el acondicionamiento de texto en su red.
Primero, digamos que tienes una red simple de dos capas.
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 )
Le gustaría condicionar las capas ocultas ( hiddens1
y hiddens2
) con texto. Cada elemento del lote aquí tendría su propio condicionamiento de texto libre.
Esto se ha reducido a ~3 pasos usando este repositorio.
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
acondicionamiento completo de la película, sin guía libre del clasificador (usado aquí)
agregar clasificador de guía gratuita para el acondicionamiento de películas
condicionamiento completo de atención cruzada
prueba de esfuerzo para el espacio-tiempo unet en 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 }
}