POET: Preference Optimization for Enhanced Text-to-Image Generation
This work introduces an input-side scaling framework that uses LLMs to rewrite text prompts before they are fed into a frozen text-to-image model. By training a prompt rewriter using iterative Direct Preference Optimization (DPO) with multiple quality rewards, the method significantly improves image quality, alignment, and aesthetics across various models without retraining the T2I backbone.