InvokeAI/invokeai/backend/stable_diffusion/extensions/inpaint_model.py
2024-07-27 13:20:58 +03:00

89 lines
3.8 KiB
Python

from __future__ import annotations
from typing import TYPE_CHECKING, Optional
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 InpaintModelExt(ExtensionBase):
"""An extension for inpainting with inpainting models. See `InpaintExt` for inpainting with non-inpainting
models.
"""
def __init__(
self,
mask: Optional[torch.Tensor],
masked_latents: Optional[torch.Tensor],
is_gradient_mask: bool,
):
"""Initialize InpaintModelExt.
Args:
mask (Optional[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 1 means that the corresponding 'pixel' should not be
inpainted.
masked_latents (Optional[torch.Tensor]): Latents of initial image, with masked out by black color inpainted area.
If mask provided, then too should be provided. Shape: (1, 1, latent_height, latent_width)
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__()
if mask is not None and masked_latents is None:
raise ValueError("Source image required for inpaint mask when inpaint model used!")
# Inverse mask, because inpaint models treat mask as: 0 - remain same, 1 - inpaint
self._mask = None
if mask is not None:
self._mask = 1 - mask
self._masked_latents = masked_latents
self._is_gradient_mask = is_gradient_mask
@staticmethod
def _is_inpaint_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 == 9
@callback(ExtensionCallbackType.PRE_DENOISE_LOOP)
def init_tensors(self, ctx: DenoiseContext):
if not self._is_inpaint_model(ctx.unet):
raise ValueError("InpaintModelExt should be used only on inpaint models!")
if self._mask is None:
self._mask = torch.ones_like(ctx.latents[:1, :1])
self._mask = self._mask.to(device=ctx.latents.device, dtype=ctx.latents.dtype)
if self._masked_latents is None:
self._masked_latents = torch.zeros_like(ctx.latents[:1])
self._masked_latents = self._masked_latents.to(device=ctx.latents.device, dtype=ctx.latents.dtype)
# Do last so that other extensions works with normal latents
@callback(ExtensionCallbackType.PRE_UNET, order=1000)
def append_inpaint_layers(self, ctx: DenoiseContext):
batch_size = ctx.unet_kwargs.sample.shape[0]
b_mask = torch.cat([self._mask] * batch_size)
b_masked_latents = torch.cat([self._masked_latents] * batch_size)
ctx.unet_kwargs.sample = torch.cat(
[ctx.unet_kwargs.sample, b_mask, b_masked_latents],
dim=1,
)
# Restore unmasked part as inpaint model can change unmasked part slightly
@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)