CILA: Confusion-based Instance-wise Logit Adjustment for Long-Tailed Recognition
Organizations: Sungkyunkwan University
Abstract
Real-world datasets are inherently class-imbalanced, leading models to favor majority classes and struggle with minority ones. Existing logit adjustment methods address this by modifying logits based on class frequencies, but their class-wise adjustments ignore instance-wise confusion and often suppress informative signals from confusing non-target classes. This results in insufficient learning of such classes, increased prediction uncertainty, and limited generalization. To address this, we propose two complementary methods. First, Confusion-based Instance-wise Logit Adjustment (CILA) adaptively adjusts logits based on instance-wise confusion between the target and non-target classes, restoring informative gradients that class-wise adjustment suppresses. Second, Batch-adaptation Noise-Injection (BNI) perturbs the target logit during training, extending the confusion-aware update to correctly classified but near-boundary samples that the penalty alone cannot reach. CILA is a loss-agnostic plug-in module that can be seamlessly integrated into existing long-tailed learning methods, and consistently improves performance across multiple benchmarks. Our code will be available at https://github.com/maya0395/CILA.
Figures & tables
| IF 10 | IF 50 | IF 100 | |||||||||||
| Method | Loss | Head | Med | Tail | All | Head | Med | Tail | All | Head | Med | Tail | All |
| Loss | CE | 67.4 0.5 | 45.7 0.5 | - | 60.7 0.5 | 69.7 0.4 | 40.2 0.6 | 18.0 0.7 | 48.3 0.3 | 72.0 0.3 | 43.5 0.6 | 10.0 0.4 | 43.4 0.3 |
| LDAM | 67.1 0.2 | 46.5 0.8 | - | 60.8 0.4 | 69.8 0.3 | 39.3 0.5 | 16.3 0.5 | 47.7 0.0 | 71.4 0.4 | 42.4 1.1 | 10.5 0.5 | 43.0 0.4 | |
| DBM | 67.7 0.5 | 46.8 0.7 | - | 61.2 0.4 | 69.8 0.2 | 40.0 0.5 | 17.7 0.5 | 48.2 0.2 | 71.7 0.8 | 42.3 0.5 | 10.2 0.4 | 43.0 0.2 | |
| CILA | 66.8 0.1 | 54.1 0.3 | - | 62.7 0.3 | 68.0 0.2 | 44.6 0.5 | 29.0 0.4 | 51.2 0.3 | 70.3 0.5 | 46.1 0.2 | 19.2 0.8 | 46.1 0.1 | |
| CE-DRW | 65.1 0.7 | 54.2 1.6 | - | 61.7 0.2 | 65.9 0.7 | 44.9 1.0 | 28.4 0.5 | 50.5 0.1 | 67.6 0.9 | 47.3 0.8 | 19.0 0.3 | 45.9 0.2 | |
| ImageNet-LT | iNaturalist 2018 | |||||||
| Method | Head | Med | Tail | All | Head | Med | Tail | All |
| CE † | 64.0 | 33.8 | 5.8 | 41.6 | 73.9 | 63.5 | 55.5 | 61.0 |
| cRT † | 58.8 | 44.0 | 26.1 | 47.3 | 69.0 | 66.0 | 63.2 | 65.2 |
| LWS † | 57.1 | 45.2 | 29.3 | 47.7 | 65.0 | 66.3 | 65.5 | 65.9 |
| CE-DRW † | 61.7 | 47.3 | 28.8 | 50.1 | 68.2 | 67.3 | 66.4 | 67.0 |
| LDAM-DRW † | 60.4 | 46.9 | 30.7 | 49.8 | - | - | - | 66.1 |
| Method | Inter-class Separability | Intra-class Compactness | ||||||
|---|---|---|---|---|---|---|---|---|
| Head | Med | Tail | All | Head | Med | Tail | All | |
| LA [ 23 ] | 6.0 | 6.0 | 5.7 | 5.9 | 28.6 | 28.8 | 29.6 | 29.0 |
| DBM-LA [ 29 ] | 7.0 | 6.3 | 6.0 | 6.2 | 31.0 | 31.9 | 33.1 | 32.0 |
| CILA-LA (Ours) | 6.8 | 6.9 | 6.1 | 6.6 | 28.1 | 28.3 | 29.3 | 28.6 |
| Components | IF 50 | IF 100 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| CILA | BNI | Head | Med | Tail | All | Head | Med | Tail | All | |
| 62.7 | 47.5 | 36.8 | 51.8 | 62.3 | 47.1 | 25.3 | 45.9 | |||
| ✓ | 64.6 | 46.8 | 36.1 | 52.1 | 64.9 | 47.0 | 25.8 | 46.9 | ||
| ✓ | ✓ | 64.3 | 47.0 | 37.3 | 52.3 | 64.6 | 47.6 | 28.0 | 47.6 | |
| ✓ | 69.8 | 42.8 | 22.1 | 50.1 | 70.3 | 45.4 | 15.2 | 45.1 | ||
| ✓ | ✓ | 63.3 | 47.9 | 37.7 | 52.4 | 62.2 | 47.1 | 29.1 | 47.0 | |
| Upper Bound | IF 50 | IF 100 | ||||||
|---|---|---|---|---|---|---|---|---|
| Head | Med | Tail | All | Head | Med | Tail | All | |
| 0.5 | 62.3 | 48.0 | 37.2 | 51.9 | 62.7 | 47.4 | 29.3 | 47.4 |
| 1.0 | 63.2 | 47.0 | 39.1 | 52.2 | 64.3 | 48.4 | 28.1 | 47.9 |
| 1.5 | 64.3 | 47.4 | 37.3 | 52.5 | 64.8 | 48.2 | 28.8 | 48.2 |
| 2.0 | 61.3 | 49.3 | 42.2 | 53.0 | 64.7 | 47.6 | 30.1 | 48.3 |
| Noise Type | IF 50 | IF 100 | ||||||
|---|---|---|---|---|---|---|---|---|
| Head | Med | Tail | All | Head | Med | Tail | All | |
| Chi | 63.3 | 48.4 | 35.5 | 52.2 | 63.4 | 48.5 | 28.5 | 47.7 |
| Gaussian | 65.0 | 47.0 | 39.0 | 52.9 | 64.3 | 48.7 | 28.9 | 48.2 |
| Rayleigh | 61.3 | 49.3 | 42.2 | 53.0 | 64.7 | 47.6 | 30.1 | 48.3 |
| in Eq. 10 | IF 50 | IF 100 | ||||||
|---|---|---|---|---|---|---|---|---|
| Head | Med | Tail | All | Head | Med | Tail | All | |
| 0.1 | 64.0 | 48.3 | 38.0 | 52.9 | 64.7 | 48.0 | 27.9 | 47.8 |
| 0.2 | 61.3 | 49.3 | 42.2 | 53.0 | 64.7 | 47.6 | 30.1 | 48.3 |
| 0.3 | 63.2 | 47.9 | 37.7 | 52.4 | 62.5 | 50.0 | 27.5 | 47.6 |
Class-Imbalanced Learning
Class-imbalanced learning develops classifiers that recognize rare classes without sacrificing performance on common ones.
See all 257 papers