SCD4VPR: Multi-modal Scene Change Detection for Long-term Visual Place Recognition Database Update
Organizations: New York University
Abstract
Long-term autonomy in mobile robotics requires maps that remain accurate as environments change over time. Visual Place Recognition (VPR), a core localization capability, degrades sharply as the temporal gap between query and database images grows, particularly across seasonal transitions. Scene Change Detection (SCD) offers a principled mechanism for database maintenance, but existing methods rely on binary, uni-modal visual features that cannot distinguish structural changes from viewpoint-induced differences - a distinction essential for correct update decisions. We propose SCD4VPR, a scene change detection that jointly reasons about what has changed and distinguishes genuine change from viewpoint-induced difference in a unified vision-language framework. SCD4VPR fuses VLM-generated semantic descriptions with visual features via cross-modal attention and refines predictions with geometric-semantic matching, producing multi-class change masks that separately identify object changes, appearance changes, and viewpoint-induced changes. We introduce NYC-CD, the first real-world street-view SCD benchmark with pixel-level multi-class annotations across 8,122 image pairs. Experiments across four SCD benchmarks show that SCD4VPR consistently improves three architecturally distinct backbones. In a controlled VPR database maintenance experiment on NYU-VPR spanning summer through late winter, we confirm that retrieval performance deteriorates substantially when the database is left unchanged, and show that SCD4VPR-guided updates recover most of this loss (+30.1 R@1 at the largest time gap) while keeping the database far more compact than naive append.
Figures & tables
| Dataset | Real/Sim | Pairs | Obj. | App. | VP. |
| CARLA-OBJCD [ 28 ] | Sim | 15000 | ✓ | ✗ | ✓ |
| Changesim [ 26 ] | Sim | 130k | ✓ | ✓ | ✗ |
| Standardsim [ 27 ] | Sim | 12718 | ✓ | ✗ | ✗ |
| CD2014 [ 29 ] | Real | 7000 | ✓ | ✗ | ✗ |
| PCD [ 23 ] | Real | 200 | ✓ | ✗ | ✗ |
| VL-CMU-CD [ 8 ] | Real | 1362 | ✓ | ✗ | ✗ |
| Model | ChangeVPR | VL-CMU-CD | PSCD | NYC-CD (ours) | ||||
|---|---|---|---|---|---|---|---|---|
| F1 | IoU | F1 | IoU | F1 | IoU | F1 | IoU | |
| GeSCF | 0.47 | 0.36 | 0.77 | 0.65 | 0.40 | 0.28 | 0.16 | 0.10 |
| GeSCF+SCD4VPR | 0.64 (+17%) | 0.55 (+19%) | 0.82 (+5%) | 0.71 (+6%) | 0.49 (+9%) | 0.37 (+9%) | 0.57 (+41%) | 0.49 (+38%) |
| RSCD | 0.24 | 0.16 | 0.83 | 0.73 | 0.54 | 0.40 | 0.13 | 0.17 |
| RSCD+SCD4VPR | 0.63 (+39%) | 0.54 (+38%) | 0.85 (+2%) | 0.75 (+2%) | 0.59 (+5%) | 0.46 (+6%) | 0.70 (+57%) | 0.58 (+51%) |
| C-3PO | 0.12 | 0.08 | 0.50 | 0.39 | 0.66 | 0.54 | 0.09 | 0.10 |
| Class | F1 | IoU | ||
|---|---|---|---|---|
| RSCD | +SCD4VPR ( ) | RSCD | +SCD4VPR ( ) | |
| Non-change | 0.899 | 0.945 (+4.6%) | 0.816 | 0.895 (+7.9%) |
| New/Missing Obj. | 0.438 | 0.472 (+3.4%) | 0.281 | 0.309 (+2.8%) |
| Appearance | 0.655 | 0.703 (+4.8%) | 0.487 | 0.542 (+5.5%) |
| Viewpoint | 0.459 | 0.563 (+10.4%) | 0.298 | 0.391 (+9.3%) |
| Mean | 0.613 | 0.671 (+5.8%) | 0.471 | 0.534 (+6.3%) |
| Method | F1 | IoU |
|---|---|---|
| RSCD | 0.127 | 0.168 |
| RSCD + Text (InternVL) | 0.513 | 0.345 |
| RSCD + Text (QwenVL) | 0.537 | 0.401 |
| RSCD + Text (GPT-4o) | 0.563 | 0.424 |
| RSCD + Text + SM | 0.584 | 0.487 |
| RSCD + Text + SM + GM | 0.696 | 0.582 |
| Strategy | Obj. | App. | VP. | No-chg. | DB size |
|---|---|---|---|---|---|
| NU (naïve update) | replace | replace | replace | replace | constant |
| R (replace) | replace | replace | skip | skip | constant |
| R+V (replace+viewpoint-add) | replace | replace | add | skip | grows |
| A (add-all) | add | add | add | skip | grows |
| NA (naïve append) | add | add | add | add | grows |
| Window | Strategy | R@1 | R@5 | R@10 | R@20 |
|---|---|---|---|---|---|
| W2 | Static ( ) | 79.7 | 86.6 | 88.0 | 89.5 |
| NU | 84.1 | 90.9 | 92.0 | 93.0 | |
| R | 82.5 | 89.5 | 90.9 | 92.4 | |
| A | 86.0 | 92.0 | 93.2 | 94.1 | |
| NA | 86.7 | 92.4 | 93.6 | 94.4 | |
| R+V | 85.5 | 91.8 | 93.0 | 94.1 |
Semantic Change Detection
Semantic change detection identifies how meanings, concepts, or scene contents differ across time in text, images, and other data.
See all 63 papers