InvokeAI/invokeai/backend/stable_diffusion/extensions/inpaint.py
Sergey Borisov c323a760a5 Suggested changes
Co-Authored-By: Ryan Dick <14897797+RyanJDick@users.noreply.github.com>
2024-07-23 23:34:28 +03:00

117 lines
5.4 KiB
Python

from __future__ import annotations
from typing import TYPE_CHECKING, Optional
import einops
import torch
from diffusers import UNet2DConditionModel
from invokeai.backend.stable_diffusion.extension_callback_type import ExtensionCallbackType
from invokeai.backend.stable_diffusion.extensions.base import ExtensionBase, callback
if TYPE_CHECKING:
from invokeai.backend.stable_diffusion.denoise_context import DenoiseContext
class InpaintExt(ExtensionBase):
"""An extension for inpainting with non-inpainting models. See `InpaintModelExt` for inpainting with inpainting
models.
"""
def __init__(
self,
mask: torch.Tensor,
is_gradient_mask: bool,
):
"""Initialize InpaintExt.
Args:
mask (torch.Tensor): The inpainting mask. Shape: (1, 1, latent_height, latent_width). Values are
expected to be in the range [0, 1]. A value of 0 means that the corresponding 'pixel' should not be
inpainted.
is_gradient_mask (bool): If True, mask is interpreted as a gradient mask meaning that the mask values range
from 0 to 1. If False, mask is interpreted as binary mask meaning that the mask values are either 0 or
1.
"""
super().__init__()
self._mask = mask
self._is_gradient_mask = is_gradient_mask
# Noise, which used to noisify unmasked part of image
# if noise provided to context, then it will be used
# if no noise provided, then noise will be generated based on seed
self._noise: Optional[torch.Tensor] = None
@staticmethod
def _is_normal_model(unet: UNet2DConditionModel):
""" Checks if the provided UNet belongs to a regular model.
The `in_channels` of a UNet vary depending on model type:
- normal - 4
- depth - 5
- inpaint - 9
"""
return unet.conv_in.in_channels == 4
def _apply_mask(self, ctx: DenoiseContext, latents: torch.Tensor, t: torch.Tensor) -> torch.Tensor:
batch_size = latents.size(0)
mask = einops.repeat(self._mask, "b c h w -> (repeat b) c h w", repeat=batch_size)
if t.dim() == 0:
# some schedulers expect t to be one-dimensional.
# TODO: file diffusers bug about inconsistency?
t = einops.repeat(t, "-> batch", batch=batch_size)
# Noise shouldn't be re-randomized between steps here. The multistep schedulers
# get very confused about what is happening from step to step when we do that.
mask_latents = ctx.scheduler.add_noise(ctx.inputs.orig_latents, self._noise, t)
# TODO: Do we need to also apply scheduler.scale_model_input? Or is add_noise appropriately scaled already?
# mask_latents = self.scheduler.scale_model_input(mask_latents, t)
mask_latents = einops.repeat(mask_latents, "b c h w -> (repeat b) c h w", repeat=batch_size)
if self._is_gradient_mask:
threshold = (t.item()) / ctx.scheduler.config.num_train_timesteps
mask_bool = mask > threshold
masked_input = torch.where(mask_bool, latents, mask_latents)
else:
masked_input = torch.lerp(mask_latents.to(dtype=latents.dtype), latents, mask.to(dtype=latents.dtype))
return masked_input
@callback(ExtensionCallbackType.PRE_DENOISE_LOOP)
def init_tensors(self, ctx: DenoiseContext):
if not self._is_normal_model(ctx.unet):
raise ValueError("InpaintExt should be used only on normal models!")
self._mask = self._mask.to(device=ctx.latents.device, dtype=ctx.latents.dtype)
self._noise = ctx.inputs.noise
# 'noise' might be None if the latents have already been noised (e.g. when running the SDXL refiner).
# We still need noise for inpainting, so we generate it from the seed here.
if self._noise is None:
self._noise = torch.randn(
ctx.latents.shape,
dtype=torch.float32,
device="cpu",
generator=torch.Generator(device="cpu").manual_seed(ctx.seed),
).to(device=ctx.latents.device, dtype=ctx.latents.dtype)
# TODO: order value
@callback(ExtensionCallbackType.PRE_STEP, order=-100)
def apply_mask_to_initial_latents(self, ctx: DenoiseContext):
ctx.latents = self._apply_mask(ctx, ctx.latents, ctx.timestep)
# TODO: order value
# TODO: redo this with preview events rewrite
@callback(ExtensionCallbackType.POST_STEP, order=-100)
def apply_mask_to_step_output(self, ctx: DenoiseContext):
timestep = ctx.scheduler.timesteps[-1]
if hasattr(ctx.step_output, "denoised"):
ctx.step_output.denoised = self._apply_mask(ctx, ctx.step_output.denoised, timestep)
elif hasattr(ctx.step_output, "pred_original_sample"):
ctx.step_output.pred_original_sample = self._apply_mask(ctx, ctx.step_output.pred_original_sample, timestep)
else:
ctx.step_output.pred_original_sample = self._apply_mask(ctx, ctx.step_output.prev_sample, timestep)
# TODO: should here be used order?
# restore unmasked part after the last step is completed
@callback(ExtensionCallbackType.POST_DENOISE_LOOP)
def restore_unmasked(self, ctx: DenoiseContext):
if self._is_gradient_mask:
ctx.latents = torch.where(self._mask > 0, ctx.latents, ctx.inputs.orig_latents)
else:
ctx.latents = torch.lerp(ctx.inputs.orig_latents, ctx.latents, self._mask)