Environmental Change Detection
for Real-World Change Analysis

ECCV 2026

1 Yonsei University 2 University of Seoul 3 Korea Institute of Science and Technology

* Corresponding authors

Environmental Change Detection (ECD) replaces predefined query-reference pair in conventional SCD with a query image and a large reference database. The change detection system must discover and integrate the reference evidence needed to determine what changed.

Abstract

Scene Change Detection (SCD) evaluates changes using predefined query-reference (i.e., present-past) image pairs. However, this formulation overlooks a critical dependency: the corresponding query-reference pair is assumed to be prepared in advance. In real-world applications, such as mobile robots, future query views cannot be known in advance, and thus their corresponding reference images cannot be predefined. To remove this dependency and push change detection toward more practical applications, we introduce Environmental Change Detection (ECD). A key aspect of ECD is to avoid unrealistically predefined and aligned query-reference pairs and instead retrieve environmental cues from an uncurated image database of reference scenes. To tackle this new challenging task, we additionally introduce an initial solution that enables change detection under unknown and imperfect query-reference conditions. The main idea of our solution is to retrieve multiple reference candidates and aggregate semantically rich representations for change detection. We further construct ECD benchmark sets by reformulating three standard change detection datasets. Extensive experimental results demonstrate the efficacy of our solution in both ECD and SCD.

Method Overview

A visual place recognition module first constructs a compact, query-specific reference subset.
From this subset, the Environment Mosaic Composer constructs a query-oriented reference representation, and the semantic aggregator refines it for comparison with the query.

Environment Mosaic Composer

EMC searches all retrieved references at multiple spatial scales and selects the most relevant patch for each query region.

The colored visualization indicates which retrieved reference contributes each patch. Finer grids approximate the query viewpoint, while the hierarchical design retains robust coarse-scale evidence.

ECD Benchmark Construction

The benchmark removes the conventional paired structure and shares one reference database across all queries.
We sparsify this database by retaining only every (s)-th reference image within each sequence.
This stride-based sampling reduces environmental coverage and provides a controllable way to adjust task difficulty.

Red boxes mark reference images retained at database stride s = 5.

Qualitative Results

In an extreme setting with one reference image per sequence and 1,001,001 distractors, the retrieved subset contains both useful references and unrelated images. EMC selectively extracts relevant evidence and supports accurate change prediction.

Quantitative Results

F1 score is used for all datasets. Higher is better.

ECD benchmark results
StrideMethodVL-CMU-CDPSCDChangeSimAverage
1RSCD0.6190.3000.3690.429
Ours0.7040.3310.3920.476
3RSCD0.5480.2400.3650.385
Ours0.6220.2800.3960.433
5RSCD0.4680.2030.3600.344
Ours0.5460.2250.3880.386
10RSCD0.3950.2240.3540.324
Ours0.4500.2450.3880.361

BibTeX

@inproceedings{cho2026environmental,
  title     = {Environmental Change Detection for Real-World Change Analysis},
  author    = {Cho, Kyusik and Woo, Suhan and Seong, Hongje and Kim, Euntai},
  booktitle = {European Conference on Computer Vision (ECCV)},
  year      = {2026},
  url       = {https://github.com/kyusik-cho/ECD}
}