Files
DiffSynth-Studio/diffsynth/pipelines/stable_diffusion_xl.py
2023-12-08 01:03:30 +08:00

127 lines
4.7 KiB
Python

from ..models import ModelManager
from ..prompts import SDXLPrompter
from ..schedulers import EnhancedDDIMScheduler
import torch
from tqdm import tqdm
from PIL import Image
import numpy as np
class SDXLPipeline(torch.nn.Module):
def __init__(self):
super().__init__()
self.scheduler = EnhancedDDIMScheduler()
def preprocess_image(self, image):
image = torch.Tensor(np.array(image, dtype=np.float32) * (2 / 255) - 1).permute(2, 0, 1).unsqueeze(0)
return image
@torch.no_grad()
def __call__(
self,
model_manager: ModelManager,
prompter: SDXLPrompter,
prompt,
negative_prompt="",
cfg_scale=7.5,
clip_skip=1,
clip_skip_2=2,
init_image=None,
denoising_strength=1.0,
refining_strength=0.0,
height=1024,
width=1024,
num_inference_steps=20,
tiled=False,
tile_size=64,
tile_stride=32,
progress_bar_cmd=tqdm,
progress_bar_st=None,
):
# Encode prompts
add_text_embeds, prompt_emb = prompter.encode_prompt(
model_manager.text_encoder,
model_manager.text_encoder_2,
prompt,
clip_skip=clip_skip, clip_skip_2=clip_skip_2,
device=model_manager.device
)
if cfg_scale != 1.0:
negative_add_text_embeds, negative_prompt_emb = prompter.encode_prompt(
model_manager.text_encoder,
model_manager.text_encoder_2,
negative_prompt,
clip_skip=clip_skip, clip_skip_2=clip_skip_2,
device=model_manager.device
)
# Prepare scheduler
self.scheduler.set_timesteps(num_inference_steps, denoising_strength)
# Prepare latent tensors
if init_image is not None:
image = self.preprocess_image(init_image).to(
device=model_manager.device, dtype=model_manager.torch_type
)
latents = model_manager.vae_encoder(
image.to(torch.float32),
tiled=tiled, tile_size=tile_size, tile_stride=tile_stride
)
noise = torch.randn(
(1, 4, height//8, width//8),
device=model_manager.device, dtype=model_manager.torch_type
)
latents = self.scheduler.add_noise(
latents.to(model_manager.torch_type),
noise,
timestep=self.scheduler.timesteps[0]
)
else:
latents = torch.randn((1, 4, height//8, width//8), device=model_manager.device, dtype=model_manager.torch_type)
# Prepare positional id
add_time_id = torch.tensor([height, width, 0, 0, height, width], device=model_manager.device)
# Denoise
for progress_id, timestep in enumerate(progress_bar_cmd(self.scheduler.timesteps)):
timestep = torch.IntTensor((timestep,))[0].to(model_manager.device)
# Classifier-free guidance
if timestep >= 1000 * refining_strength:
denoising_model = model_manager.unet
else:
denoising_model = model_manager.refiner
if cfg_scale != 1.0:
noise_pred_cond = denoising_model(
latents, timestep, prompt_emb,
add_time_id=add_time_id, add_text_embeds=add_text_embeds,
tiled=tiled, tile_size=tile_size, tile_stride=tile_stride
)
noise_pred_uncond = denoising_model(
latents, timestep, negative_prompt_emb,
add_time_id=add_time_id, add_text_embeds=negative_add_text_embeds,
tiled=tiled, tile_size=tile_size, tile_stride=tile_stride
)
noise_pred = noise_pred_uncond + cfg_scale * (noise_pred_cond - noise_pred_uncond)
else:
noise_pred = denoising_model(
latents, timestep, prompt_emb,
add_time_id=add_time_id, add_text_embeds=add_text_embeds,
tiled=tiled, tile_size=tile_size, tile_stride=tile_stride
)
latents = self.scheduler.step(noise_pred, timestep, latents)
if progress_bar_st is not None:
progress_bar_st.progress(progress_id / len(self.scheduler.timesteps))
# Decode image
latents = latents.to(torch.float32)
image = model_manager.vae_decoder(latents, tiled=tiled, tile_size=tile_size, tile_stride=tile_stride)[0]
image = image.cpu().permute(1, 2, 0).numpy()
image = Image.fromarray(((image / 2 + 0.5).clip(0, 1) * 255).astype("uint8"))
return image