Istanbul's Duplicate Image Crisis: The Key Decisions That Will Shape the City's Visual Archive

Istanbul's municipal archive holds tens of thousands of photographs documenting everything from Sultanahmet's Ottoman-era facades to the contested shoreline developments along the Golden Horn — but a growing portion of that collection is duplicated, mislabelled, or filed twice across incompatible systems. The problem has reached a point where administrators at the Istanbul Metropolitan Municipality's digital heritage unit can no longer ignore the backlog. A decision on how to resolve it is expected before the end of the third quarter of 2026.

The timing matters for a specific reason. Istanbul is midway through a broader urban digitisation push that accelerated after the February 2023 Kahramanmaraş earthquakes, when the destruction of analogue records across affected provinces underlined just how fragile unmanaged archives can be. The municipality, under Mayor Ekrem İmamoğlu's administration, committed to upgrading its digital infrastructure as part of a post-disaster resilience programme. Duplicate image files — some estimates from archival specialists put redundancy rates in large civic databases at 15 to 30 percent — corrode storage budgets and make search retrieval unreliable, undermining the very purpose of digitisation.

Where the Problem Lives and What It Costs

The duplication is concentrated in two places. The Istanbul Atatürk Library on Millet Caddesi in Beyazıt holds physical and scanned collections that were digitised in separate waves between 2018 and 2024, each using different file-naming conventions. Staff who have spoken generally about the challenge — without being identified by role — have described a situation where the same photograph of, say, the Galata Bridge construction exists under three different catalogue numbers. Separately, the KUDEB unit responsible for monitoring protected heritage structures across districts including Fatih and Eyüpsultan maintains its own image database, which overlaps with both the library's holdings and records held by the General Directorate of Foundations in Ankara.

Storage is not free. Commercial cloud storage for large institutional archives typically runs between 0.02 and 0.05 US dollars per gigabyte per month at scale — a figure that compounds quickly when duplicates inflate a collection by even 20 percent. The municipality has not published a specific line-item cost for redundant image storage, but the principle is straightforward: every unnecessary copy is budget wasted that could fund field photography of at-risk neighbourhoods like Tarlabaşı or Balat, where gentrification and structural deterioration are actively changing streetscapes.

The technical options on the table are broadly understood in the archival management field. Automated deduplication software can flag identical or near-identical files using hash-matching and perceptual image comparison algorithms. The risk is false positives — two photographs of the same building taken seconds apart may be genuinely distinct historical records. A human review layer is almost always necessary, which means budget for trained archivists, not just software licences.

The Decisions Ahead

Three choices will define what happens next. First, the municipality must decide whether to run deduplication centrally — consolidating the Atatürk Library and KUDEB databases into a single system — or to clean each archive independently and establish interoperability standards afterward. Centralisation is faster but politically complicated when multiple directorates guard their own data. Second, officials need to set a retention policy: when two duplicates are found, which version becomes the canonical record, and what metadata standard governs it? Turkey adopted its e-Government interoperability framework, eTR, years ago, but its application to photographic heritage archives has been inconsistent. Third, and most consequentially for the public, is the question of open access. A cleaned, well-structured image archive could become a publicly searchable resource — something cities like Amsterdam have managed through their Stadsarchief platform. Istanbul, with its unmatched density of Ottoman, Byzantine, and early-Republican visual history, has the raw material to build something comparable.

The practical advice from archival management specialists who work with municipal bodies — without naming individuals not on the record — is consistent: do not wait for a perfect unified system before beginning deduplication. Start with the highest-value collections, document every deletion decision with an audit trail, and build the governance policy alongside the technical work, not after it. The Atatürk Library's Beyazıt reading room is open to researchers now. The quality of what those researchers can find there in five years depends on decisions made in the next six months.