Paris's Battle Against Duplicate Images in Public Archives: What Officials, Experts and Key Figures Are Saying

A quiet but increasingly urgent argument is playing out across Paris's public institutions this summer: what should happen when digital archives contain thousands of duplicate or near-identical images, and who bears the cost of cleaning them up? Archivists at the Bibliothèque nationale de France on the Rue de Richelieu, urban planners attached to the Société du Grand Paris, and housing officials managing Seine riverfront regeneration files all say the problem has reached a point where it can no longer be ignored.

The timing matters. Paris is three years into activating the legacy infrastructure built for the 2024 Olympics, and dozens of municipal agencies are consolidating image-heavy documentation — construction records, urban design renderings, event photography — into shared platforms. When duplicate files accumulate unchecked, storage costs climb, search functions degrade, and legally required public access to official records becomes slower and more opaque.

What the Experts Are Saying

Specialists in digital asset management who have worked with Parisian institutions describe the problem in consistent terms. Duplicate images are rarely exact copies. More often they are near-duplicates: slightly different crops, resized versions, watermarked and unwatermarked variants of the same photograph. Automated deduplication tools catch exact matches efficiently, but near-duplicates require human review or more sophisticated perceptual hashing algorithms, which cost more to deploy and maintain. Institutions operating under constrained public budgets — a persistent condition under the current Macron government's second-term austerity framing — have repeatedly deferred the investment.

At the Atelier parisien d'urbanisme, known as APUR, staff responsible for maintaining the visual documentation of Paris's evolving skyline along the Seine between the Bibliothèque François-Mitterrand and the Pont de Tolbiac have pointed internally to image duplication as a practical drag on project delivery. APUR's geodata and cartography teams process thousands of aerial and ground-level images each year as part of Seine riverbank regeneration tracking. Without a standardised deduplication protocol, the same photograph can appear under multiple file names in multiple departmental folders, making audits slower and inter-agency sharing unreliable.

The Grand Paris Express project has its own version of the problem. The Société du Grand Paris manages construction documentation for 68 new or redesigned stations across four new metro lines. Environmental impact assessments, contractor submissions, and public consultation records filed between 2018 and 2025 alone run to millions of pages and images. A 2024 internal review — the existence of which was reported by trade publication Archimag — flagged image duplication as one of several document management issues inflating the digital archive beyond workable size, though the specific findings of that review have not been made public.

The Policy Gap and What Comes Next

France has a legal framework for public records management through the Direction des Archives de France, which operates under the Ministry of Culture. But that framework was written primarily for text documents, and its application to image assets — particularly those generated by infrastructure projects or urban planning exercises — remains ambiguous. Institutions are left to write their own internal policies, which vary widely in rigour.

The Mairie de Paris's Direction de l'Urbanisme updated its digital asset guidelines in March 2025, introducing for the first time a mandatory deduplication check before images are transferred to long-term storage. The policy applies to files generated by the bureau responsible for the 13th arrondissement's ongoing Seine Rive Gauche development zone. Whether it will be extended citywide remains an open question inside the Hôtel de Ville.

Professionals in the field say the most practical near-term step is procurement: when public agencies next renew contracts for document management platforms, they should require built-in perceptual hashing as a baseline feature rather than an add-on. The European Union's interoperability frameworks for public sector digital infrastructure, updated under the 2022 Interoperable Europe Act, give procurement officers a legitimate policy hook to demand those specifications. For Paris's institutions, the summer consolidation cycle — when annual archive transfers typically occur — is the logical moment to act. If agencies wait until the next budget round, another year's worth of duplicates will have accumulated.