InvokeAI/invokeai/backend/image_util/safety_checker.py
psychedelicious dd9daf8efb chore: ruff
2024-03-01 10:42:33 +11:00

67 lines
2.3 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.
"""
import numpy as np
from PIL import Image
import invokeai.backend.util.logging as logger
from invokeai.app.services.config import InvokeAIAppConfig
from invokeai.backend.util.devices import choose_torch_device
from invokeai.backend.util.silence_warnings import SilenceWarnings
config = InvokeAIAppConfig.get_config()
CHECKER_PATH = "core/convert/stable-diffusion-safety-checker"
class SafetyChecker:
"""
Wrapper around SafetyChecker model.
"""
safety_checker = None
feature_extractor = None
tried_load: bool = False
@classmethod
def _load_safety_checker(cls):
if cls.tried_load:
return
if config.nsfw_checker:
try:
from diffusers.pipelines.stable_diffusion.safety_checker import StableDiffusionSafetyChecker
from transformers import AutoFeatureExtractor
cls.safety_checker = StableDiffusionSafetyChecker.from_pretrained(config.models_path / CHECKER_PATH)
cls.feature_extractor = AutoFeatureExtractor.from_pretrained(config.models_path / CHECKER_PATH)
logger.info("NSFW checker initialized")
except Exception as e:
logger.warning(f"Could not load NSFW checker: {str(e)}")
else:
logger.info("NSFW checker loading disabled")
cls.tried_load = True
@classmethod
def safety_checker_available(cls) -> bool:
cls._load_safety_checker()
return cls.safety_checker is not None
@classmethod
def has_nsfw_concept(cls, image: Image.Image) -> bool:
if not cls.safety_checker_available():
return False
device = 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]