@article{promptechoannotationfreerewardfromvision,
  title = {PromptEcho: Annotation-Free Reward from Vision-Language Models for Text-to-Image Reinforcement Learning},
  author = {Jinlong Liu and Wanggui He and Peng Zhang and Mushui Liu and Hao Jiang and Pipei Huang},
  year = {2026},
  eprint = {2604.12652},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2604.12652},
}