stable-diffusion-mat-outpainting-primer / outpainting_example2.py
max
added example scripts
89023a7
# %%
# an example script of how to do outpainting with diffusers img2img pipeline
# should be compatible with any stable diffusion model
# (only tested with runwayml/stable-diffusion-v1-5)
from typing import Callable, List, Optional, Union
from PIL import Image
import PIL
import numpy as np
import torch
from diffusers import StableDiffusionImg2ImgPipeline
from diffusers.pipelines.stable_diffusion import StableDiffusionPipelineOutput
from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion_img2img import preprocess
pipe = StableDiffusionImg2ImgPipeline.from_pretrained(
"runwayml/stable-diffusion-v1-5",
revision="fp16",
torch_dtype=torch.float16,
)
pipe.set_use_memory_efficient_attention_xformers(True)
pipe.to("cuda")
# %%
# load the image, extract the mask
rgba = Image.open('primed_image_with_alpha_channel.png')
mask_full = np.array(rgba)[:, :, 3] == 0
rgb = rgba.convert('RGB')
# %%
# resize/convert the mask to the right size
# for 512x512, the mask should be 1x4x64x64
hw = np.array(mask_full.shape)
h, w = (hw - hw % 32) // 8
mask_image = Image.fromarray(mask_full).resize((w, h), Image.NEAREST)
mask = (np.array(mask_image) == 0)[None, None]
mask = np.concatenate([mask]*4, axis=1)
mask = torch.from_numpy(mask).to('cuda')
mask.shape
# %%
@torch.no_grad()
def outpaint(
self: StableDiffusionImg2ImgPipeline,
prompt: Union[str, List[str]] = None,
image: Union[torch.FloatTensor, PIL.Image.Image] = None,
strength: float = 0.8,
num_inference_steps: Optional[int] = 50,
guidance_scale: Optional[float] = 7.5,
negative_prompt: Optional[Union[str, List[str]]] = None,
num_images_per_prompt: Optional[int] = 1,
eta: Optional[float] = 0.0,
generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
prompt_embeds: Optional[torch.FloatTensor] = None,
negative_prompt_embeds: Optional[torch.FloatTensor] = None,
output_type: Optional[str] = "pil",
return_dict: bool = True,
callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None,
callback_steps: Optional[int] = 1,
**kwargs,
):
r"""
copy of the original img2img pipeline's __call__()
https://github.com/huggingface/diffusers/blob/main/src/diffusers/pipelines/stable_diffusion/pipeline_stable_diffusion_img2img.py
Changes are marked with <EDIT> and </EDIT>
"""
# message = "Please use `image` instead of `init_image`."
# init_image = deprecate("init_image", "0.14.0", message, take_from=kwargs)
# image = init_image or image
# 1. Check inputs. Raise error if not correct
self.check_inputs(prompt, strength, callback_steps,
negative_prompt, prompt_embeds, negative_prompt_embeds)
# 2. Define call parameters
if prompt is not None and isinstance(prompt, str):
batch_size = 1
elif prompt is not None and isinstance(prompt, list):
batch_size = len(prompt)
else:
batch_size = prompt_embeds.shape[0]
device = self._execution_device
# here `guidance_scale` is defined analog to the guidance weight `w` of equation (2)
# of the Imagen paper: https://arxiv.org/pdf/2205.11487.pdf . `guidance_scale = 1`
# corresponds to doing no classifier free guidance.
do_classifier_free_guidance = guidance_scale > 1.0
# 3. Encode input prompt
prompt_embeds = self._encode_prompt(
prompt,
device,
num_images_per_prompt,
do_classifier_free_guidance,
negative_prompt,
prompt_embeds=prompt_embeds,
negative_prompt_embeds=negative_prompt_embeds,
)
# 4. Preprocess image
image = preprocess(image)
# 5. set timesteps
self.scheduler.set_timesteps(num_inference_steps, device=device)
timesteps, num_inference_steps = self.get_timesteps(
num_inference_steps, strength, device)
latent_timestep = timesteps[:1].repeat(batch_size * num_images_per_prompt)
# 6. Prepare latent variables
latents = self.prepare_latents(
image, latent_timestep, batch_size, num_images_per_prompt, prompt_embeds.dtype, device, generator
)
# <EDIT>
# store the encoded version of the original image to overwrite
# what the UNET generates "underneath" our image on each step
encoded_original = (self.vae.config.scaling_factor *
self.vae.encode(
image.to(latents.device, latents.dtype)
).latent_dist.mean)
# </EDIT>
# 7. Prepare extra step kwargs. TODO: Logic should ideally just be moved out of the pipeline
extra_step_kwargs = self.prepare_extra_step_kwargs(generator, eta)
# 8. Denoising loop
num_warmup_steps = len(timesteps) - \
num_inference_steps * self.scheduler.order
with self.progress_bar(total=num_inference_steps) as progress_bar:
for i, t in enumerate(timesteps):
# expand the latents if we are doing classifier free guidance
latent_model_input = torch.cat(
[latents] * 2) if do_classifier_free_guidance else latents
latent_model_input = self.scheduler.scale_model_input(
latent_model_input, t)
# predict the noise residual
noise_pred = self.unet(latent_model_input, t,
encoder_hidden_states=prompt_embeds).sample
# perform guidance
if do_classifier_free_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, **extra_step_kwargs).prev_sample
# <EDIT> paste unmasked regions from the original image
noise = torch.randn(
encoded_original.shape, generator=generator, device=device)
noised_encoded_original = self.scheduler.add_noise(
encoded_original, noise, t).to(noise_pred.device, noise_pred.dtype)
latents[mask] = noised_encoded_original[mask]
# </EDIT>
# call the callback, if provided
if i == len(timesteps) - 1 or ((i + 1) > num_warmup_steps and (i + 1) % self.scheduler.order == 0):
progress_bar.update()
if callback is not None and i % callback_steps == 0:
callback(i, t, latents)
# 9. Post-processing
image = self.decode_latents(latents)
# 10. Run safety checker
image, has_nsfw_concept = self.run_safety_checker(
image, device, prompt_embeds.dtype)
# 11. Convert to PIL
if output_type == "pil":
image = self.numpy_to_pil(image)
if not return_dict:
return (image, has_nsfw_concept)
return StableDiffusionPipelineOutput(images=image, nsfw_content_detected=has_nsfw_concept)
# %%
image = outpaint(
pipe,
image=rgb,
prompt="forest in the style of Tim Hildebrandt",
strength=0.5,
num_inference_steps=50,
guidance_scale=7.5,
).images[0]
image
# %%
# the vae does lossy encoding, we could get better quality if we pasted the original image into our result.
# this may yield visible edges