Size-Informed Representations for Unsupervised Image Clustering

Proposed framework for size-informed deep image clustering using late-fusion size injection.

Abstract

Unsupervised image clustering aims to group unlabeled images into semantically meaningful categories without human supervision. While deep learning-based clustering frameworks such as semantic clustering by adopting neighbors (SCAN) and deep embedding clustering (DEC) have recently achieved promising results, the impact of preprocessing strategies—such as aspect-preserving padding and direct resizing—on clustering performance remains underexplored. This paper investigates both implicit size information (through preprocessing) and explicit size information injection in deep clustering frameworks, using a high-stakes, real-world dataset with significant image heterogeneity. We systematically evaluate SCAN and DINOv2-DEC clustering frameworks across multiple strategies: direct resizing, aspect ratio-preserving padding and late-fusion size injection with spectral encoding.

Philipp Rajah Moura Srivastava, Charilaos Apostolidis, Saumya Pailwan, Patrick Koller, and Leandros Stefanopoulos

Accepted and presented at the IEEE ICIP 2025 Satellite Workshop: “Generative AI for World Simulations and Communications & Celebrating 40 Years of Excellence in Education: Honoring Prof. Aggelos Katsaggelos,” Anchorage, Alaska, USA, Sept 14, 2025.

BibTeX Citation

@INPROCEEDINGS{Srivastava_2025_SizeInformedClustering,
  author={Srivastava, Philipp Rajah Moura and Apostolidis, Charilaos and Pailwan, Saumya and Koller, Patrick and Stefanopoulos, Leandros},
  booktitle={2025 IEEE International Conference on Image Processing Workshops (ICIPW)}, 
  title={Size-Informed Representations for Unsupervised Image Clustering}, 
  year={2025},
  volume={},
  number={},
  pages={743-748},
  keywords={Visualization;Image coding;Conferences;Semantics;Pipelines;Data models;Image preprocessing;Standards;Unsupervised Image Clustering;SelfSupervised Learning;Size Encoding;Image Preprocessing;Deep Embedded Clustering},
  doi={10.1109/ICIPW68931.2025.11386144}}
Patrick Koller
Patrick Koller
PhD Candidate

I work on scientific machine learning, focusing on physics-informed neural networks, neural operators, and large-scale physical simulations.