# Two-Step Graph Classification on the Basis of Hierarchical Graphs

### Anthony Gillioz, Kaspar Riesen

#### 2023

#### Abstract

A common method to solve the non-trivial task of classifying general graphs is to employ graph matching in conjunction with a distance- or similarity-based classifier. Unfortunately, optimal graph matching has a high computational complexity hindering its application on large graphs. In order to make matchings also feasible for larger graphs, it has been proposed to work on size-reduced graphs rather than on their original counterparts. In the present paper, we propose a novel method that is based on this idea to further reduce the processing time. In particular, we change the standard classification scheme into a two-step classification method. In the first step, we start with strongly reduced versions of the graphs – having a manageable amount of nodes – in order to prune as many graphs as possible. The second step – the actual classification – is then performed on the remaining graphs only (in their original size). We conduct experimental evaluations on five datasets to research the benefits and limitations of this novel two-step graph classification method. The main finding is that we can substantially speed up the graph matching while preserving satisfying classification accuracy.

Download#### Paper Citation

#### in Harvard Style

Gillioz A. and Riesen K. (2023). **Two-Step Graph Classification on the Basis of Hierarchical Graphs**. In *Proceedings of the 12th International Conference on Pattern Recognition Applications and Methods - Volume 1: ICPRAM,* ISBN 978-989-758-626-2, pages 296-303. DOI: 10.5220/0011657000003411

#### in Bibtex Style

@conference{icpram23,

author={Anthony Gillioz and Kaspar Riesen},

title={Two-Step Graph Classification on the Basis of Hierarchical Graphs},

booktitle={Proceedings of the 12th International Conference on Pattern Recognition Applications and Methods - Volume 1: ICPRAM,},

year={2023},

pages={296-303},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0011657000003411},

isbn={978-989-758-626-2},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the 12th International Conference on Pattern Recognition Applications and Methods - Volume 1: ICPRAM,

TI - Two-Step Graph Classification on the Basis of Hierarchical Graphs

SN - 978-989-758-626-2

AU - Gillioz A.

AU - Riesen K.

PY - 2023

SP - 296

EP - 303

DO - 10.5220/0011657000003411