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Update Utils.py
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from diffusers import AutoencoderKL, UNet2DConditionModel, LMSDiscreteScheduler
from transformers import CLIPTextModel, CLIPTokenizer
from tqdm.auto import tqdm
from PIL import Image
import torch
class MingleModel:
def __init__(self):
# Set device
self.torch_device = "cuda" if torch.cuda.is_available() else "cpu"
# Load the autoencoder model which will be used to decode the latents into image space.
use_auth_token = "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"
self.vae = AutoencoderKL.from_pretrained("CompVis/stable-diffusion-v1-4", subfolder="vae",
use_auth_token=use_auth_token).to(self.torch_device)
# Load the tokenizer and text encoder to tokenize and encode the text.
self.tokenizer = CLIPTokenizer.from_pretrained("openai/clip-vit-large-patch14", use_auth_token=use_auth_token)
self.text_encoder = CLIPTextModel.from_pretrained("openai/clip-vit-large-patch14", use_auth_token=use_auth_token).to(self.torch_device)
# # The UNet model for generating the latents.
self.unet = UNet2DConditionModel.from_pretrained("CompVis/stable-diffusion-v1-4", subfolder="unet",use_auth_token=use_auth_token).to(self.torch_device)
# The noise scheduler
self.scheduler = LMSDiscreteScheduler(beta_start=0.00085, beta_end=0.012, beta_schedule="scaled_linear",
num_train_timesteps=1000)
def do_tokenizer(self, prompt):
return self.tokenizer([prompt], padding="max_length", max_length=self.tokenizer.model_max_length, truncation=True,
return_tensors="pt")
def get_text_encoder(self, text_input):
return self.text_encoder(text_input.input_ids.to(self.torch_device))[0]
def latents_to_pil(self, latents):
# bath of latents -> list of images
latents = (1 / 0.18215) * latents
with torch.no_grad():
image = self.vae.decode(latents).sample
image = (image / 2 + 0.5).clamp(0, 1)
image = image.detach().cpu().permute(0, 2, 3, 1).numpy()
images = (image * 255).round().astype("uint8")
pil_images = [Image.fromarray(image) for image in images]
return pil_images
def generate_with_embs(self, text_embeddings, generator_int=32, num_inference_steps=30, guidance_scale=7.5):
height = 512 # default height of Stable Diffusion
width = 512 # default width of Stable Diffusion
num_inference_steps = num_inference_steps # Number of denoising steps
guidance_scale = guidance_scale # Scale for classifier-free guidance
generator = torch.manual_seed(generator_int) # Seed generator to create the inital latent noise
batch_size = 1
max_length = 77
uncond_input = self.tokenizer(
[""] * batch_size, padding="max_length", max_length=max_length, return_tensors="pt"
)
with torch.no_grad():
uncond_embeddings = self.text_encoder(uncond_input.input_ids.to(self.torch_device))[0]
text_embeddings = torch.cat([uncond_embeddings, text_embeddings])
# Prep Scheduler
self.scheduler.set_timesteps(num_inference_steps)
# Prep latents
latents = torch.randn((batch_size, self.unet.in_channels, height // 8, width // 8), generator=generator)
latents = latents.to(self.torch_device)
latents = latents * self.scheduler.init_noise_sigma
# Loop
for i, t in tqdm(enumerate(self.scheduler.timesteps)):
# expand the latents if we are doing classifier-free guidance to avoid doing two forward passes.
latent_model_input = torch.cat([latents] * 2)
sigma = self.scheduler.sigmas[i]
latent_model_input = self.scheduler.scale_model_input(latent_model_input, t)
# predict the noise residual
with torch.no_grad():
noise_pred = self.unet(latent_model_input, t, encoder_hidden_states=text_embeddings)["sample"]
# perform guidance
noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)
noise_pred = noise_pred_uncond + guidance_scale * (noise_pred_text - noise_pred_uncond)
# compute the previous noisy sample x_t -> x_t-1
latents = self.scheduler.step(noise_pred, t, latents).prev_sample
return self.latents_to_pil(latents)[0]