PolygonGNN: Representation Learning for Polygonal Geometries with Heterogeneous Visibility Graph
Dazhou Yu, Yuntong Hu, Yun Li, Liang Zhao
TL;DR
Multipolygon representation learning lags behind single-polygon methods by neglecting inner and inter-polygon relationships. The authors introduce PolygonGNN, which converts multipolygons into a heterogeneous visibility graph, uses a spanning-tree sampling strategy for efficiency, and employs a lossless five-tuple geometric representation to achieve rotation- and translation-invariance. A dedicated Multipolygon-GNN then performs two-hop message passing to capture hierarchical spatial patterns across polygon parts, producing discriminative embeddings. Across five datasets, the approach achieves state-of-the-art results and demonstrates robustness to perturbations, highlighting its practical value for GIS, urban planning, and related spatial analyses.
Abstract
Polygon representation learning is essential for diverse applications, encompassing tasks such as shape coding, building pattern classification, and geographic question answering. While recent years have seen considerable advancements in this field, much of the focus has been on single polygons, overlooking the intricate inner- and inter-polygonal relationships inherent in multipolygons. To address this gap, our study introduces a comprehensive framework specifically designed for learning representations of polygonal geometries, particularly multipolygons. Central to our approach is the incorporation of a heterogeneous visibility graph, which seamlessly integrates both inner- and inter-polygonal relationships. To enhance computational efficiency and minimize graph redundancy, we implement a heterogeneous spanning tree sampling method. Additionally, we devise a rotation-translation invariant geometric representation, ensuring broader applicability across diverse scenarios. Finally, we introduce Multipolygon-GNN, a novel model tailored to leverage the spatial and semantic heterogeneity inherent in the visibility graph. Experiments on five real-world and synthetic datasets demonstrate its ability to capture informative representations for polygonal geometries. Code and data are available at \href{https://github.com/dyu62/PolyGNN}{$github.com/dyu62/PolyGNN$}.
