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

Istanbul's municipal digital infrastructure has a problem hiding in plain sight. Tens of thousands of duplicate photographs — many of them aerial surveys, construction permit images, and heritage documentation files — are clogging the Istanbul Metropolitan Municipality's central asset management system, creating bottlenecks that delay planning decisions and cost archivists and urban planners hundreds of hours of manual review time each year. The question now is what gets done about it, and who carries the cost.

The issue matters urgently because Istanbul is not standing still. The city is mid-way through several major urban transformation projects under the municipality's post-2023 earthquake preparedness drive, which accelerated sharply following the Kahramanmaraş disaster of February that year. Documentation accuracy is not a bureaucratic nicety — it is, in many cases, a structural safety question. A misidentified building photograph in the Fatih or Zeytinburnu districts, both flagged as high seismic-risk zones, can mean the wrong structure gets prioritised or cleared.

Where the Bottlenecks Are Worst

The duplication problem is most acute in two areas: the heritage inventory managed by the Istanbul Archaeological Museums network, which covers thousands of registered Ottoman-era structures across districts including Sultanahmet and Eyüpsultan, and the urban transformation imagery collected by the İBB's Kentsel Dönüşüm Müdürlüğü — the directorate responsible for coordinating building renewal across the city's 39 districts. Sources familiar with the directorate's workflow, speaking in general terms publicly available in municipal planning reports, have noted that duplicate file rates in some project folders can run as high as 30 percent, meaning roughly one in three images stored requires human cross-checking before it can be officially used.

For the heritage portfolio, the stakes are different but equally pointed. The UNESCO-listed Historic Areas of Istanbul — which include the Topkapı Palace grounds, the Süleymaniye Mosque complex, and stretches of the old Byzantine land walls — require meticulous photographic records as part of conservation management plans. Duplicate or mislabelled images submitted to Turkey's Ministry of Culture and Tourism for periodic review can delay funding approvals and trigger compliance queries from the World Heritage Committee in Paris.

The Istanbul Archaeological Museums alone hold records covering more than 17,000 catalogued artefacts and hundreds of immovable heritage structures. Managing that archive without a reliable deduplication protocol has become increasingly untenable as digitisation has accelerated since 2021.

The Decisions Ahead

Three choices are now on the table, each with different cost and political implications. The first is a full automated deduplication sweep using AI-assisted image hashing — a technical solution that several European municipal archives, including those in Amsterdam and Vienna, have already implemented. Istanbul's İBB has the server infrastructure at its Sütlüce data centre on the Golden Horn's European bank to run such a process, but budget allocation remains unconfirmed for the 2026 fiscal cycle, which runs through December.

The second option is a phased manual audit, department by department, starting with the highest-risk urban transformation zones. This is slower — estimates based on comparable archival projects suggest a full audit of a 50,000-image dataset takes a trained team roughly six to eight months — but it allows for quality control that automated tools sometimes miss, particularly with low-resolution construction site photographs where hashing algorithms produce false negatives.

The third, and most politically sensitive, path is outsourcing the work to a private digital asset management firm under a tender process. Given Istanbul Mayor Ekrem İmamoğlu's administration has consistently prioritised transparency in municipal contracting — a stance that emerged partly in response to prior controversies — any outsourcing tender would face scrutiny from both the opposition and the central government's oversight bodies.

A decision is expected before the İBB's autumn budget session, tentatively scheduled for late September 2026. Whichever route is chosen, heritage specialists and urban planners working in districts from Beyoğlu to Kadıköy will be watching closely. Getting the archive right is not just about tidiness. In a city rebuilding its relationship with seismic risk, and defending its world heritage status simultaneously, a photograph in the wrong folder is not a minor error.