English

H-SPAM: Hierarchical Superpixel Anything Model

Computer Vision and Pattern Recognition 2026-04-14 v1

Abstract

Superpixels offer a compact image representation by grouping pixels into coherent regions. Recent methods have reached a plateau in terms of segmentation accuracy by generating noisy superpixel shapes. Moreover, most existing approaches produce a single fixed-scale partition that limits their use in vision pipelines that would benefit multi-scale representations. In this work, we introduce H-SPAM (Hierarchical Superpixel Anything Model), a unified framework for generating accurate, regular, and perfectly nested hierarchical superpixels. Starting from a fine partition, guided by deep features and external object priors, H-SPAM constructs the hierarchy through a two-phase region merging process that first preserves object consistency and then allows controlled inter-object grouping. The hierarchy can also be modulated using visual attention maps or user input to preserve important regions longer in the hierarchy. Experiments on standard benchmarks show that H-SPAM strongly outperforms existing hierarchical methods in both accuracy and regularity, while performing on par with most recent state-of-the-art non-hierarchical methods. Code and pretrained models are available: https://github.com/waldo-j/hspam.

Keywords

Cite

@article{arxiv.2604.11218,
  title  = {H-SPAM: Hierarchical Superpixel Anything Model},
  author = {Julien Walther and Rémi Giraud and Michaël Clément},
  journal= {arXiv preprint arXiv:2604.11218},
  year   = {2026}
}
R2 v1 2026-07-01T12:05:57.771Z