InvokeAI/invokeai/backend/image_util/safety_checker.py
2024-05-14 07:23:38 +10:00

85 lines
3.4 KiB
Python

"""
This module defines a singleton object, "safety_checker" that
wraps the safety_checker model. It respects the global "nsfw_checker"
configuration variable, that allows the checker to be supressed.
"""
from pathlib import Path
import numpy as np
from diffusers.pipelines.stable_diffusion.safety_checker import StableDiffusionSafetyChecker
from PIL import Image, ImageFilter
from transformers import AutoFeatureExtractor
import invokeai.backend.util.logging as logger
from invokeai.app.services.config.config_default import get_config
from invokeai.backend.util.devices import TorchDevice
from invokeai.backend.util.silence_warnings import SilenceWarnings
repo_id = "CompVis/stable-diffusion-safety-checker"
CHECKER_PATH = "core/convert/stable-diffusion-safety-checker"
class SafetyChecker:
"""
Wrapper around SafetyChecker model.
"""
feature_extractor = None
safety_checker = None
@classmethod
def _load_safety_checker(cls):
if cls.safety_checker is not None and cls.feature_extractor is not None:
return
try:
model_path = get_config().models_path / CHECKER_PATH
if model_path.exists():
cls.feature_extractor = AutoFeatureExtractor.from_pretrained(model_path)
cls.safety_checker = StableDiffusionSafetyChecker.from_pretrained(model_path)
else:
model_path.mkdir(parents=True, exist_ok=True)
cls.feature_extractor = AutoFeatureExtractor.from_pretrained(repo_id)
cls.feature_extractor.save_pretrained(model_path, safe_serialization=True)
cls.safety_checker = StableDiffusionSafetyChecker.from_pretrained(repo_id)
cls.safety_checker.save_pretrained(model_path, safe_serialization=True)
except Exception as e:
logger.warning(f"Could not load NSFW checker: {str(e)}")
@classmethod
def has_nsfw_concept(cls, image: Image.Image) -> bool:
cls._load_safety_checker()
if cls.safety_checker is None or cls.feature_extractor is None:
return False
device = TorchDevice.choose_torch_device()
features = cls.feature_extractor([image], return_tensors="pt")
features.to(device)
cls.safety_checker.to(device)
x_image = np.array(image).astype(np.float32) / 255.0
x_image = x_image[None].transpose(0, 3, 1, 2)
with SilenceWarnings():
checked_image, has_nsfw_concept = cls.safety_checker(images=x_image, clip_input=features.pixel_values)
return has_nsfw_concept[0]
@classmethod
def blur_if_nsfw(cls, image: Image.Image) -> Image.Image:
if cls.has_nsfw_concept(image):
logger.warning("A potentially NSFW image has been detected. Image will be blurred.")
blurry_image = image.filter(filter=ImageFilter.GaussianBlur(radius=32))
caution = cls._get_caution_img()
# Center the caution image on the blurred image
x = (blurry_image.width - caution.width) // 2
y = (blurry_image.height - caution.height) // 2
blurry_image.paste(caution, (x, y), caution)
image = blurry_image
return image
@classmethod
def _get_caution_img(cls) -> Image.Image:
import invokeai.app.assets.images as image_assets
caution = Image.open(Path(image_assets.__path__[0]) / "caution.png")
return caution.resize((caution.width // 2, caution.height // 2))