HiProto: Hierarchical Prototype Learning for Interpretable Object Detection Under Low-quality Conditions

TL;DR

HiProto introduces a hierarchical prototype learning framework for interpretable object detection that maintains robustness under low-quality conditions without complex architectures.

Contribution

It proposes a novel hierarchical prototype learning paradigm with specialized loss functions and pseudo label strategies for improved interpretability and semantic discrimination.

Findings

Achieves competitive detection performance on low-quality datasets.

Provides interpretable prototype responses without image enhancement.

Outperforms existing methods in semantic discrimination under degradation.

Abstract

Interpretability is essential for deploying object detection systems in critical applications, especially under low-quality imaging conditions that degrade visual information and increase prediction uncertainty. Existing methods either enhance image quality or design complex architectures, but often lack interpretability and fail to improve semantic discrimination. In contrast, prototype learning enables interpretable modeling by associating features with class-centered semantics, which can provide more stable and interpretable representations under degradation. Motivated by this, we propose HiProto, a new paradigm for interpretable object detection based on hierarchical prototype learning. By constructing structured prototype representations across multiple feature levels, HiProto effectively models class-specific semantics, thereby enhancing both semantic discrimination and interpretability. Building upon prototype modeling, we first propose a Region-to-Prototype Contrastive Loss (RPC-Loss) to enhance the semantic focus of prototypes on target regions. Then, we propose a Prototype Regularization Loss (PR-Loss) to improve the distinctiveness among class prototypes. Finally, we propose a Scale-aware Pseudo Label Generation Strategy (SPLGS) to suppress mismatched supervision for RPC-Loss, thereby preserving the robustness of low-level prototype representations. Experiments on ExDark, RTTS, and VOC2012-FOG demonstrate that HiProto achieves competitive results while offering clear interpretability through prototype responses, without relying on image enhancement or complex architectures. Our code will be available at https://github.com/xjlDestiny/HiProto.git.