Scroll-Net: Geometry-Aware Constrained Decoding for Multi-Page Document Hierarchy Parsing

Wanting Lin, Hiuyi Cheng, Wei Pan, Lianwen Jin


Abstract
Hierarchical Document Structure Analysis (HDSA) aims to recover the logical tree and reading order of a document, providing a structural foundation for downstream tasks such as document question answering, information extraction, and long-form document understanding. Extending HDSA to multi-page documents remains challenging, as pagination introduces discontinuities between page-local coordinate systems, making it difficult to link structurally related elements across pages. We present Scroll-Net, a geometry-aware constrained decoding framework for multi-page document hierarchy parsing. Scroll-Net maps page-local coordinates into a unified scroll-space coordinate frame, enabling direct comparison of cross-page elements. It employs a dual-stream encoder to disentangle geometric and semantic cues, injecting geometric inductive bias before multimodal fusion. Under the pre-order convention used by the evaluated benchmarks, Scroll-Net constrains autoregressive parent decoding with a hard reading-order causal mask. This backward-pointer constraint makes decoded parent graphs acyclic under the imposed order while retaining O(K) per-step decoding, reducing inference latency by 36.5% and peak memory by 46.5%. Across four benchmarks, Scroll-Net remains competitive on simple layouts while achieving state-of-the-art results on structurally complex documents, improving TEDS by 4.8 points on DocHieNet.
Anthology ID:
2026.emnlp-main.1483
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
33908–33922
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1483/
DOI:
Bibkey:
Cite (ACL):
Wanting Lin, Hiuyi Cheng, Wei Pan, and Lianwen Jin. 2026. Scroll-Net: Geometry-Aware Constrained Decoding for Multi-Page Document Hierarchy Parsing. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 33908–33922, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Scroll-Net: Geometry-Aware Constrained Decoding for Multi-Page Document Hierarchy Parsing (Lin et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1483.pdf