CVJun 23, 2025

NSFW-Classifier Guided Prompt Sanitization for Safe Text-to-Image Generation

arXiv:2506.18325v14 citationsh-index: 5
Originality Incremental advance
AI Analysis

This addresses safety risks for users and developers of text-to-image technology, though it is incremental as it builds on existing classifier methods.

The paper tackled the problem of harmful content generation in text-to-image models by proposing NSFW-Classifier Guided Prompt Sanitization (PromptSan), which detoxifies prompts without altering model architecture, achieving state-of-the-art performance in reducing harmful content across multiple metrics.

The rapid advancement of text-to-image (T2I) models, such as Stable Diffusion, has enhanced their capability to synthesize images from textual prompts. However, this progress also raises significant risks of misuse, including the generation of harmful content (e.g., pornography, violence, discrimination), which contradicts the ethical goals of T2I technology and hinders its sustainable development. Inspired by "jailbreak" attacks in large language models, which bypass restrictions through subtle prompt modifications, this paper proposes NSFW-Classifier Guided Prompt Sanitization (PromptSan), a novel approach to detoxify harmful prompts without altering model architecture or degrading generation capability. PromptSan includes two variants: PromptSan-Modify, which iteratively identifies and replaces harmful tokens in input prompts using text NSFW classifiers during inference, and PromptSan-Suffix, which trains an optimized suffix token sequence to neutralize harmful intent while passing both text and image NSFW classifier checks. Extensive experiments demonstrate that PromptSan achieves state-of-the-art performance in reducing harmful content generation across multiple metrics, effectively balancing safety and usability.

Foundations

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