Beyond Augmentation: Leveraging Inter-Instance Relation in Self-Supervised Representation Learning
Ali Javidani, Babak Nadjar Araabi, Mohammad Amin Sadeghi
TL;DR
Addressing the limitation of intra-sample augmentation in self-supervised representation learning, this work introduces inter-instance relations by constructing KNN graphs for both teacher and student streams and refining representations through multi-hop graph neural networks. The method combines a teacher–student self-distillation with a graph-based refinement stage, using a circular history of neighbor relationships and a 3-layer MLP projection guided by a cross-entropy objective, followed by cosine-based alignment. Empirical results on CIFAR-10, ImageNet-100, and ImageNet-1K show consistent improvements over state-of-the-art SSL methods, with substantial gains on smaller datasets and notable benefits on large-scale data, demonstrating the value of inter-sample relational context. The proposed framework offers a scalable, fully self-supervised approach that leverages graph structure to enhance feature representations and generalization.
Abstract
This paper introduces a novel approach that integrates graph theory into self-supervised representation learning. Traditional methods focus on intra-instance variations generated by applying augmentations. However, they often overlook important inter-instance relationships. While our method retains the intra-instance property, it further captures inter-instance relationships by constructing k-nearest neighbor (KNN) graphs for both teacher and student streams during pretraining. In these graphs, nodes represent samples along with their latent representations. Edges encode the similarity between instances. Following pretraining, a representation refinement phase is performed. In this phase, Graph Neural Networks (GNNs) propagate messages not only among immediate neighbors but also across multiple hops, thereby enabling broader contextual integration. Experimental results on CIFAR-10, ImageNet-100, and ImageNet-1K demonstrate accuracy improvements of 7.3%, 3.2%, and 1.0%, respectively, over state-of-the-art methods. These results highlight the effectiveness of the proposed graph based mechanism. The code is publicly available at https://github.com/alijavidani/SSL-GraphNNCLR.
