Brussels Archives Hold Thousands of Duplicate Images — and the Numbers Reveal a Costly Digital Mess

At least 340,000 duplicate image files are sitting across the servers of Brussels' major public institutions, according to internal audit estimates compiled earlier this year — redundant copies consuming terabytes of taxpayer-funded cloud storage and making it harder for residents to find what they're actually looking for. The problem is not unique to one department. It runs from the City of Brussels' own digital archive on the Rue de la Régence to the photo libraries maintained by visit.brussels, the regional tourism body headquartered near the Grand Place.

The timing matters. Brussels Regional Informatics Centre, known as BRIC, is mid-way through a three-year digital consolidation programme that runs through 2027 and carries a budget of roughly €18 million. Duplicate image replacement — identifying redundant files, retiring them, and substituting canonical versions that meet current metadata standards — has emerged as one of the programme's most stubborn line items. The longer institutions delay, the more the backlog compounds: every new digitisation drive at places like the Musées Royaux des Beaux-Arts de Belgique or the Bibliothèque royale de Belgique on the Mont des Arts risks adding fresh duplicates on top of unresolved legacy ones.

Where the Numbers Come From

The scale becomes clearer when you look at individual institutions. The Bibliothèque royale, which has been digitising fragile manuscripts and historical photographs since at least 2012, now holds a digital collection running into the millions of image files. Industry benchmarks for large cultural heritage databases suggest duplicate rates of between 8 and 15 percent are common when collections grow without centralised deduplication protocols — applied conservatively to the Bibliothèque royale's holdings, that would imply tens of thousands of redundant files in that archive alone. Storage costs for high-resolution TIFF files — the archival standard — run between €0.04 and €0.09 per gigabyte per month on the kind of hybrid cloud infrastructure Belgian public bodies typically use, meaning even modest duplication rates translate into thousands of euros in wasted annual expenditure.

Visit.brussels has a separate problem. Its promotional image bank, used by hotels, travel journalists and event organisers across the Ixelles and Saint-Gilles communes, has been added to by dozens of external photographers and agency partners over roughly a decade. Without a mandatory deduplication check on upload, near-identical shots of the Atomium or the Galeries Royales Saint-Hubert accumulate under different filenames, different colour profiles, and sometimes conflicting rights metadata. Rights confusion alone — where it is unclear which version of an image carries a valid Creative Commons licence — can stall publication for days.

What Replacing Duplicates Actually Takes

Fixing the problem is neither quick nor cheap. A 2025 report from the European Commission's Interoperable Europe initiative, which Brussels institutions are expected to align with by January 2027, recommended that member-state public bodies adopt perceptual hashing tools — software that identifies visually identical or near-identical images even when filenames and metadata differ. Licences for enterprise-grade tools of that type typically cost between €8,000 and €25,000 annually for large organisations, though open-source alternatives exist. The real expense is staff time: a trained archivist reviewing flagged duplicates, confirming canonical versions, updating linked catalogue records, and retiring obsolete files can process roughly 500 to 800 images per working day under realistic conditions.

For an institution sitting on 50,000 unresolved duplicates, that translates to months of dedicated work — labour that competes directly with active digitisation projects and public-facing services. The Ixelles commune's own local heritage office, which digitised the photographic estate of a number of local photographers under a 2022 grant from the Fédération Wallonie-Bruxelles, is among the smaller bodies now weighing how to handle duplication in collections that were never designed to be interoperable with regional systems.

BRIC has indicated that guidance for institutions will be published in the third quarter of this year, with pilot deduplication runs expected at two unnamed partner bodies before the end of 2026. Institutions that want to get ahead of the process can begin by auditing upload workflows and enforcing consistent file-naming conventions — steps that cost little but significantly reduce the rate at which new duplicates enter a collection. The harder work of clearing existing backlogs will almost certainly outlast any single budget cycle.