Mine-JEPA: In-Domain Self-Supervised Learning for Mine-Like Object Classification in Side-Scan Sonar
Organizations: Maum AI Inc. · Seoul National University · KAIST · Yonsei University
Abstract
Side-scan sonar (SSS) mine classification is a challenging maritime vision problem characterized by extreme data scarcity and a large domain gap from natural images. While self-supervised learning (SSL) and general-purpose vision foundation models have shown strong performance in general vision and several specialized domains, their use in SSS remains largely unexplored. We present Mine-JEPA, the first in-domain SSL pipeline for SSS mine classification, using SIGReg, a regularization-based SSL loss, to pretrain on only 1,170 unlabeled sonar images. In the binary mine vs. non-mine setting, Mine-JEPA achieves an F1 score of 0.935, outperforming fine-tuned DINOv3 (0.922), a foundation model pretrained on 1.7B images. For 3-class mine-like object classification, Mine-JEPA reaches 0.820 with synthetic data augmentation, again outperforming fine-tuned DINOv3 (0.810). We further observe that applying in-domain SSL to foundation models degrades performance by 10--13 percentage points, suggesting that stronger pretrained models do not always benefit from additional domain adaptation. In addition, Mine-JEPA with a compact ViT-Tiny backbone achieves competitive performance while using 4x fewer parameters than DINOv3. These results suggest that carefully designed in-domain self-supervised learning is a viable alternative to much larger foundation models in data-scarce maritime sonar imagery.
Figures & tables
| Method | Init | SSL Data | Best Probe | macro-F1 | NOMBO F1 | Acc |
|---|---|---|---|---|---|---|
| Random Init | Random | — | ft_mlp | 0.557 0.052 | 0.439 0.091 | 58.3 4.0% |
| IN1K Only | IN1K | — | ft_mlp | 0.739 0.028 | 0.647 0.046 | 76.3 2.6% |
| DINOv3 | DINOv3 | — | ft_mlp | 0.810 0.025 | 0.700 0.068 | 83.4 2.0% |
| SimCLR | IN1K | Real+Syn | finetune | 0.801 0.038 | 0.693 0.084 | 82.6 2.6% |
| VICReg | IN1K | Real+Syn | finetune | 0.800 0.037 | 0.676 0.068 | 82.8 3.0% |
| BYOL | IN1K | Real+Syn | finetune | 0.693 0.028 | 0.539 0.059 | 72.8 2.4% |
| Hyperparameter | Value |
|---|---|
| Projection dim. | 16 |
| 0.1 | |
| Views ( ) | 4 |
| Batch size | 1024 |
| Optimizer | AdamW (weight decay 0.05) |
| Learning rate |
| Method | Init | Params | 3-class F1 | 2-class F1 | MILCO Recall (%) |
|---|---|---|---|---|---|
| DINOv3 | DINOv3 | 21.5M | 0.810 0.025 | 0.922 0.018 | 88.1 1.3 |
| Mine-JEPA (ViT-S) | IN1K | 21.6M | 0.820 0.018 | 0.935 0.020 | 90.9 2.4 |
| Mine-JEPA (ViT-Tiny) | IN1K | 5.5M | 0.814 0.026 | 0.935 0.020 | 91.4 2.3 |
| Config | Init | SSL Data | macro-F1 | ||
|---|---|---|---|---|---|
| Random Init | Random | — | — | 0.557 0.052 | — |
| Natural Aug SSL | Random | Real ∗ | 0.02 | 0.312 0.040 | %p |
| DINOv3 + SIGReg | DINOv3 | Real | 0.02 | 0.706 0.068 | %p vs DINOv3 |
| DINOv3 + SIGReg | DINOv3 | Real+Syn | 0.02 | 0.677 0.031 | %p vs DINOv3 |
| SIGReg (SSS aug) | Random | Real | 0.02 | 0.725 0.021 | — |
| + IN1K init | IN1K | Real | 0.02 | 0.756 0.054 | +3.1%p vs Random SSL |
| SSL Method | Loss Type | proj. dim | Real only | Real+Syn | |
|---|---|---|---|---|---|
| SIGReg (Ours) | Regularization | 16 | 0.799 0.036 | 0.820 0.018 | +2.1%p |
| VICReg | Regularization | 2048 | 0.774 0.025 | 0.800 0.037 | +2.6%p |
| SimCLR | Contrastive | 128 | 0.806 0.013 | 0.801 0.038 | %p |
| BYOL | Distillation | 256 | 0.774 0.031 | 0.693 0.028 | %p |
Classification
Classification maps observations to discrete labels, including familiar, unknown, hierarchical, or multiple categories.
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