ToonOut is a fine-tuned variant of BiRefNet specialized for background removal in anime-style images.
BiRefNet performs strongly on realistic imagery but struggles with stylized content (e.g., hair wisps, line art, transparency).
Fine-tuned on the ToonOut Dataset (1,228 images), ToonOut delivers a notable boost for anime segmentation:

Pixel Accuracy: 95.3% → 99.5% (on our test set)

Model Details

Architecture: BiRefNet (fine-tuned)
License: MIT
Training data: ToonOut Dataset (CC-BY 4.0)

Example usage

Please refer to the demo notebook from our GitHub repo.

Citation

If you use ToonOut, please cite:

bibtex

@misc{muratori2025toonout,
  title={ToonOut: Fine-tuned Background Removal for Anime Characters},
  author={Muratori, Matteo and Seytre, Joël},
  year={2025},
  eprint={2509.06839},
  archivePrefix={arXiv},
  primaryClass={cs.CV},
  url={https://arxiv.org/abs/2509.06839},
  doi={10.48550/arXiv.2509.06839}
}

Authors & Contact

Authors: Matteo Muratori (University of Bologna, Kartoon AI), Joël Seytre (Kartoon AI)
Contact: joel@kartoon.ai, matteo.muratori9@studio.unibo.it

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Project by Kartoon AI, powering toongether, check us out at kartoon.ai & toongether.ai