Istanbul's Duplicate Image Problem: The Key Decisions That Will Shape the City's Visual Heritage

Istanbul's public archives are drowning in themselves. Across the Istanbul Metropolitan Municipality's documentation centers, the Atatürk Library in Beyoğlu, and the digital holdings of the Istanbul Archaeological Museums directorate on Osman Hamdi Bey Yokuşu, archivists have identified sprawling catalogues of duplicate, degraded, and mislabeled photographic images — some triplicated, some contradictory, some simply wrong. The question of what to do with them has moved from a bureaucratic footnote to an urgent institutional decision with real consequences for cultural memory.

Why now? Two pressures have converged. The Istanbul Metropolitan Municipality, led by CHP mayor Ekrem İmamoğlu, has been pushing a broad digitisation drive for municipal records since 2024, partly as a transparency exercise and partly as infrastructure for the city's urban planning departments managing post-earthquake risk assessments. At the same time, the broader aftermath of the February 2023 Kahramanmaraş earthquakes accelerated citywide audits of structural and documentary records — including photographic surveys of at-risk neighbourhoods like Zeytinburnu and Avcılar, where liquefaction risk maps depend partly on historical site photography. When duplicate images populate those databases, decisions about building vulnerability can be compromised.

The Institutional Tangle

The problem is not simply technical. Istanbul's photographic archives are split across at least four distinct institutional chains of custody. The Atatürk Library holds print collections dating to the late Ottoman period. The Istanbul Metropolitan Municipality's GIS and urban planning directorate maintains digitised survey images. The Istanbul Archaeological Museums manage excavation photography. And SALT Galata, the research institution at Bankalar Caddesi in Karaköy, holds a substantial independent visual archive now partially accessible online. None of these institutions operates under a single deduplication protocol, and there is no shared metadata standard that would allow automated cross-referencing between them.

The result is predictable redundancy. A single Ottoman-era photograph of the Galata Tower, for instance, may exist in four separate collections under four different accession numbers, catalogued with inconsistent dates and photographer attributions. Multiply that across tens of thousands of images and the archive becomes, in practical terms, unreliable — expensive to store, difficult to search, and prone to generating conflicting historical records.

Istanbul's municipal digitisation budget for cultural heritage was reported in 2024 budget documents at approximately 47 million Turkish lira for the year, a figure that archivists working in the sector have noted is stretched thin given the lira's sustained depreciation. With inflation running above 60 percent annually for much of 2024 and 2025, the real purchasing power of those allocations has shrunk considerably, making automated deduplication software licences — priced in euros or dollars — harder to procure.

What Comes Next

The decisions ahead break into three distinct phases. First, institutions must agree on a shared metadata framework — a technical but politically loaded negotiation, since it requires the Municipality, the Museums directorate under the Ministry of Culture and Tourism, and independent bodies like SALT Galata to cede some control over how their holdings are described and cross-referenced. Talks between municipal and ministerial archivists are understood to be ongoing, though no formal agreement has been announced publicly.

Second, someone must establish a replacement and retention policy: which image survives when duplicates are identified, and who holds the authoritative copy. Archivists in similar situations in cities like Amsterdam and Barcelona have adopted a model where the highest-resolution original is retained by the originating institution and a standardised derivative is shared to a central portal. Istanbul does not yet have that central portal, though the Municipality has discussed a public-facing heritage database anchored at its Fatih district offices.

Third — and most consequentially — the process must define what counts as a duplicate. Two photographs of the same building taken a decade apart are not duplicates; they are a historical sequence. Getting that distinction wrong in an automated cull could permanently erase documentation of how neighbourhoods like Tarlabaşı or the Süleymaniye slopes changed before and after urban renewal. The archivists making those calls, working largely without additional staffing, are the people on whom Istanbul's visual memory now depends. Their decisions, made in relative obscurity over the coming 18 months, will be largely irreversible.