Istanbul Races to Purge Duplicate Heritage Images From Its Digital Archives — But Lags Behind Rome and Amsterdam

Istanbul's municipal cultural body, the Istanbul Metropolitan Municipality's Cultural Directorate, is sitting on tens of thousands of digitised heritage photographs — and a growing share of them are duplicates. The problem, long dismissed as a low-priority clerical headache, has quietly become a liability for the city's tourism and urban planning arms as they compete for attention with cities that have already invested in systematic duplicate-image replacement programmes.

The issue matters now for practical reasons. Turkey's tourism sector pulled in roughly 50 million foreign visitors in 2024, with Istanbul accounting for the largest share of arrivals. The images that appear in municipal portals, UNESCO submissions, and licensed media packs directly shape how planners, investors, and travellers perceive the city. When the same blurred shot of the Galata Tower appears seventeen times under different file names in the same archive, or when a Bosphorus drone photograph filed under 'Beşiktaş waterfront' actually shows the Üsküdar ferry terminal, decisions get made on faulty visual data.

What Other Cities Have Done

Rome's municipal archive, managed through the Archivio Storico Capitolino, completed a two-year deduplication project in 2023 that cleared approximately 340,000 redundant image files from its public-access database, according to documentation published by the Comune di Roma. Amsterdam's City Archives — the Stadsarchief Amsterdam — deployed an AI-assisted hashing tool beginning in 2022 that cross-references pixel-level similarities and automatically flags near-duplicate scans of the same physical photograph. By the end of 2024, the Stadsarchief reported processing more than 1.2 million images through the system.

Istanbul has no equivalent programme with a published timeline or budget. The Istanbul Metropolitan Municipality's ISKI and cultural arms each maintain separate image repositories that do not currently share a unified deduplication protocol, according to publicly available municipal budget documents for 2025. The city's broader smart-city initiative, the Istanbul Metropolitan Municipality's IBB Smart City platform launched in 2021, has focused primarily on transport and energy data rather than archival media management.

On the tourism side, the Istanbul Convention & Visitors Bureau — which markets the city internationally under the brand Istanbul Destination — licenses image packages to travel operators globally. Sector professionals working with the bureau have noted publicly, in conference presentations at the Lütfi Kırdar Congress Centre in Harbiye, that repeated images of the same Sultanahmet mosque angles dominate the licensed library while neighbourhoods like Balat, Fener, and Kadıköy's Moda district are underrepresented and often misfiled.

The Local Stakes

The stakes are sharpest in the context of urban planning. Following the February 2023 Kahramanmaraş earthquakes, Istanbul accelerated its earthquake risk mapping and neighbourhood vulnerability assessments. Visual documentation of at-risk buildings — particularly in older districts like Fatih and Eyüpsultan — feeds directly into insurance assessments and municipal demolition-and-rebuild decisions. Duplicate or mislabelled building photographs in planning databases create real administrative risk.

The Fatih Municipality has digitised building records for roughly 18,000 structures in its district, a figure cited in its 2024 annual activity report. But deduplication of those records has not been addressed in any published follow-up document, meaning the same façade may appear under multiple addresses or duplicate survey entries.

For heritage preservation specifically, the problem compounds over time. Every year that the KUDEB — the Protection Implementation and Inspection Bureau under the Istanbul Metropolitan Municipality — logs restoration photographs without a deduplication layer, the archive grows harder to audit. Rome and Amsterdam both addressed this before their archives crossed the one-million-file threshold. Istanbul's municipal image holdings are estimated to have passed that point several years ago.

The practical path forward is not especially expensive by municipal standards. The Stadsarchief Amsterdam's deduplication project cost approximately €280,000 over two years. For Istanbul, which approved a total IMM budget of 326 billion Turkish lira for 2025, the barrier is not funding — it is institutional coordination between the municipality's separate directorates. Pilot programmes targeting the Sultanahmet and Beyoğlu district archives first, where image volume and tourism demand are highest, would be the most efficient starting point. The IBB Smart City platform already has the technical infrastructure to host such a tool. The question is whether a work order actually gets signed.