# flake8: noqa: C901
import inspect
from copy import deepcopy
from typing import Optional, Union
import numpy as np
import torch
from diffusers import AutoPipelineForText2Image
from diffusers.pipelines.wuerstchen import DEFAULT_STAGE_C_TIMESTEPS
from huggingface_hub import hf_hub_download
from mmengine import print_log
from mmengine.model import BaseModel
from peft import get_peft_model
from torch import nn
from diffengine.models.archs import create_peft_config
from diffengine.registry import MODELS
@MODELS.register_module()
[docs]class WuerstchenPriorModel(BaseModel):
"""`Wuerstchen Prior.
<https://arxiv.org/abs/2306.00637>`_
Args:
----
tokenizer (dict): Config of tokenizer.
scheduler (dict): Config of scheduler.
text_encoder (dict): Config of text encoder.
image_encoder (dict): Config of image encoder.
prior (dict): Config of prior.
decoder_model (str): pretrained decoder model name of Wuerstchen.
Defaults to 'warp-ai/wuerstchen'.
prior_model (str): pretrained prior model name of Wuerstchen.
Defaults to 'warp-ai/wuerstchen-prior'.
loss (dict): Config of loss. Defaults to
``dict(type='L2Loss', loss_weight=1.0)``.
prior_lora_config (dict, optional): The LoRA config dict for Prior.
example. dict(type="LoRA", r=4). `type` is chosen from `LoRA`,
`LoHa`, `LoKr`. Other config are same as the config of PEFT.
https://github.com/huggingface/peft
Defaults to None.
text_encoder_lora_config (dict, optional): The LoRA config dict for
Text Encoder. example. dict(type="LoRA", r=4). `type` is chosen
from `LoRA`, `LoHa`, `LoKr`. Other config are same as the config of
PEFT. https://github.com/huggingface/peft
Defaults to None.
prior_loss_weight (float): The weight of prior preservation loss.
It works when training dreambooth with class images.
data_preprocessor (dict, optional): The pre-process config of
:class:`SDDataPreprocessor`.
noise_generator (dict, optional): The noise generator config.
Defaults to ``dict(type='WhiteNoise')``.
timesteps_generator (dict, optional): The timesteps generator config.
Defaults to ``dict(type='WuerstchenRandomTimeSteps')``.
input_perturbation_gamma (float): The gamma of input perturbation.
The recommended value is 0.1 for Input Perturbation.
Defaults to 0.0.
finetune_text_encoder (bool, optional): Whether to fine-tune text
encoder. Defaults to False.
gradient_checkpointing (bool): Whether or not to use gradient
checkpointing to save memory at the expense of slower backward
pass. Defaults to False.
"""
def __init__(
self,
tokenizer: dict,
scheduler: dict,
text_encoder: dict,
image_encoder: dict,
prior: dict,
decoder_model: str = "warp-ai/wuerstchen",
prior_model: str = "warp-ai/wuerstchen-prior",
loss: dict | None = None,
prior_lora_config: dict | None = None,
text_encoder_lora_config: dict | None = None,
prior_loss_weight: float = 1.,
data_preprocessor: dict | nn.Module | None = None,
noise_generator: dict | None = None,
timesteps_generator: dict | None = None,
input_perturbation_gamma: float = 0.0,
*,
finetune_text_encoder: bool = False,
gradient_checkpointing: bool = False,
) -> None:
if data_preprocessor is None:
data_preprocessor = {"type": "SDDataPreprocessor"}
if noise_generator is None:
noise_generator = {}
if timesteps_generator is None:
timesteps_generator = {}
if loss is None:
loss = {}
super().__init__(data_preprocessor=data_preprocessor)
if (
prior_lora_config is not None) and (
text_encoder_lora_config is not None) and (
not finetune_text_encoder):
print_log(
"You are using LoRA for Prior and text encoder. "
"But you are not set `finetune_text_encoder=True`. "
"We will set `finetune_text_encoder=True` for you.")
finetune_text_encoder = True
if text_encoder_lora_config is not None:
assert finetune_text_encoder, (
"If you want to use LoRA for text encoder, "
"you should set finetune_text_encoder=True."
)
if finetune_text_encoder and prior_lora_config is not None:
assert text_encoder_lora_config is not None, (
"If you want to finetune text encoder with LoRA Prior, "
"you should set text_encoder_lora_config."
)
self.decoder_model = decoder_model
self.prior_lora_config = deepcopy(prior_lora_config)
self.text_encoder_lora_config = deepcopy(text_encoder_lora_config)
self.finetune_text_encoder = finetune_text_encoder
self.prior_loss_weight = prior_loss_weight
self.gradient_checkpointing = gradient_checkpointing
self.input_perturbation_gamma = input_perturbation_gamma
if not isinstance(loss, nn.Module):
loss = MODELS.build(
loss,
default_args={"type": "L2Loss", "loss_weight": 1.0})
self.loss_module: nn.Module = loss
assert not self.loss_module.use_snr, \
"WuerstchenPriorModel does not support SNR loss."
self.tokenizer = MODELS.build(
tokenizer,
default_args={"pretrained_model_name_or_path": prior_model,
} if not inspect.isclass(tokenizer.get("type")) else None)
self.text_encoder = MODELS.build(
text_encoder,
default_args={"pretrained_model_name_or_path": prior_model,
} if not inspect.isclass(text_encoder.get("type")) else None)
pretrained_image_encoder = image_encoder.pop("pretrained_image_encoder", False)
self.image_encoder = MODELS.build(image_encoder)
if pretrained_image_encoder:
pretrained_checkpoint_file = hf_hub_download(
"dome272/wuerstchen", filename="model_v2_stage_b.pt")
state_dict = torch.load(pretrained_checkpoint_file, map_location="cpu")
self.image_encoder.load_state_dict(state_dict["effnet_state_dict"])
self.scheduler = MODELS.build(scheduler)
self.prior = MODELS.build(
prior,
default_args={"pretrained_model_name_or_path": prior_model,
} if not inspect.isclass(prior.get("type")) else None)
self.noise_generator = MODELS.build(
noise_generator,
default_args={"type": "WhiteNoise"})
self.timesteps_generator = MODELS.build(
timesteps_generator,
default_args={"type": "WuerstchenRandomTimeSteps"})
self.prepare_model()
self.set_lora()
[docs] def set_lora(self) -> None:
"""Set LORA for model."""
if self.text_encoder_lora_config is not None:
text_encoder_lora_config = create_peft_config(
self.text_encoder_lora_config)
self.text_encoder = get_peft_model(
self.text_encoder, text_encoder_lora_config)
self.text_encoder.print_trainable_parameters()
if self.prior_lora_config is not None:
prior_lora_config = create_peft_config(self.prior_lora_config)
self.prior = get_peft_model(self.prior, prior_lora_config)
self.prior.print_trainable_parameters()
[docs] def prepare_model(self) -> None:
"""Prepare model for training.
Disable gradient for some models.
"""
if self.gradient_checkpointing:
self.prior.enable_gradient_checkpointing()
if self.finetune_text_encoder:
self.text_encoder.gradient_checkpointing_enable()
self.image_encoder.requires_grad_(requires_grad=False)
print_log("Set Image Encoder untrainable.", "current")
if not self.finetune_text_encoder:
self.text_encoder.requires_grad_(requires_grad=False)
print_log("Set Text Encoder untrainable.", "current")
@property
[docs] def device(self) -> torch.device:
"""Get device information.
Returns
-------
torch.device: device.
"""
return next(self.parameters()).device
[docs] def train(self, *, mode: bool = True) -> None:
"""Convert the model into training mode."""
super().train(mode)
self.image_encoder.eval()
if not self.finetune_text_encoder:
self.text_encoder.eval()
@torch.no_grad()
[docs] def infer(self,
prompt: list[str],
negative_prompt: str | None = None,
height: int | None = None,
width: int | None = None,
num_inference_steps: int = 50,
output_type: str = "pil",
**kwargs) -> list[np.ndarray]:
"""Inference function.
Args:
----
prompt (`List[str]`):
The prompt or prompts to guide the image generation.
negative_prompt (`Optional[str]`):
The prompt or prompts to guide the image generation.
Defaults to None.
height (int, optional):
The height in pixels of the generated image. Defaults to None.
width (int, optional):
The width in pixels of the generated image. Defaults to None.
num_inference_steps (int): Number of inference steps.
Defaults to 50.
output_type (str): The output format of the generate image.
Choose between 'pil' and 'latent'. Defaults to 'pil'.
**kwargs: Other arguments.
"""
pipeline = AutoPipelineForText2Image.from_pretrained(
self.decoder_model,
prior_prior=self.prior,
prior_text_encoder=self.text_encoder,
prior_tokenizer=self.tokenizer,
torch_dtype=torch.float32,
)
pipeline.to(self.device)
pipeline.set_progress_bar_config(disable=True)
images = []
for p in prompt:
image = pipeline(
p,
negative_prompt=negative_prompt,
num_inference_steps=num_inference_steps,
prior_timesteps=DEFAULT_STAGE_C_TIMESTEPS,
height=height,
width=width,
output_type=output_type,
**kwargs).images[0]
if output_type == "latent":
images.append(image)
else:
images.append(np.array(image))
del pipeline
torch.cuda.empty_cache()
return images
[docs] def val_step(
self,
data: Union[tuple, dict, list] # noqa
) -> list:
"""Val step."""
msg = "val_step is not implemented now, please use infer."
raise NotImplementedError(msg)
[docs] def test_step(
self,
data: Union[tuple, dict, list] # noqa
) -> list:
"""Test step."""
msg = "test_step is not implemented now, please use infer."
raise NotImplementedError(msg)
[docs] def loss(self,
model_pred: torch.Tensor,
noise: torch.Tensor,
timesteps: torch.Tensor,
weight: torch.Tensor | None = None) -> dict[str, torch.Tensor]:
"""Calculate loss."""
loss_dict = {}
# calculate loss in FP32
if self.loss_module.use_snr:
loss = self.loss_module(
model_pred.float(),
noise.float(),
timesteps,
self.scheduler._alpha_cumprod(timesteps, self.device), # noqa
"epsilon",
weight=weight)
else:
loss = self.loss_module(
model_pred.float(), noise.float(), weight=weight)
loss_dict["loss"] = loss
return loss_dict
[docs] def forward(
self,
inputs: dict,
data_samples: Optional[list] = None, # noqa
mode: str = "loss") -> dict:
"""Forward function.
Args:
----
inputs (dict): The input dict.
data_samples (Optional[list], optional): The data samples.
Defaults to None.
mode (str, optional): The mode. Defaults to "loss".
Returns:
-------
dict: The loss dict.
"""
assert mode == "loss"
num_batches = len(inputs["img"])
if "result_class_image" in inputs:
# use prior_loss_weight
weight = torch.cat([
torch.ones((num_batches // 2, )),
torch.ones((num_batches // 2, )) * self.prior_loss_weight,
]).float().reshape(-1, 1, 1, 1)
else:
weight = None
image_embeds = self.image_encoder(inputs["img"])
# scale
image_embeds = image_embeds.add(1.0).div(42.0)
noise = self.noise_generator(image_embeds)
timesteps = self.timesteps_generator(num_batches,
self.device)
noisy_latents = self._preprocess_model_input(image_embeds, noise, timesteps)
inputs_text = self.tokenizer(
inputs["text"],
max_length=self.tokenizer.model_max_length,
padding="max_length",
truncation=True,
return_tensors="pt")
prompt_embeds = self.text_encoder(
inputs_text.input_ids.to(self.device),
attention_mask=inputs_text.attention_mask.to(self.device),
).last_hidden_state
model_pred = self.prior(
noisy_latents,
timesteps,
prompt_embeds)
return self.loss(model_pred, noise, timesteps, weight)