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Marius Aasan

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

2 papers
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2

TMLR Journal 2026 Journal Article

SPoT: Subpixel Placement of Tokens in Vision Transformers

  • Martine Hjelkrem-Tan
  • Marius Aasan
  • Gabriel Y. Arteaga
  • Adín Ramírez Rivera

Vision Transformers naturally accommodate sparsity, yet standard tokenization methods confine features to discrete patch grids. This constraint prevents models from fully exploiting sparse regimes, forcing awkward compromises. We propose Subpixel Placement of Tokens (SPoT), a novel tokenization strategy that positions tokens continuously within images, effectively sidestepping grid-based limitations. With our proposed oracle-guided search, we uncover substantial performance gains achievable with ideal subpixel token positioning, drastically reducing the number of tokens necessary for accurate predictions during inference. SPoT provides a new direction for flexible, efficient, and interpretable ViT architectures, redefining sparsity as a strategic advantage rather than an imposed limitation.

NeurIPS Conference 2025 Conference Paper

Differentiable Hierarchical Visual Tokenization

  • Marius Aasan
  • Martine Hjelkrem Tan
  • Nico Catalano
  • Changkyu Choi
  • Adín Ramírez Rivera

Vision Transformers rely on fixed patch tokens that ignore the spatial and semantic structure of images. In this work, we introduce an end-to-end differentiable tokenizer that adapts to image content with pixel-level granularity while remaining backward-compatible with existing architectures for retrofitting pretrained models. Our method uses hierarchical model selection with information criteria to provide competitive performance in both image-level classification and dense-prediction tasks, and even supports out-of-the-box raster-to-vector conversion.