How Istanbul's Historic Image Archive Ended Up Full of Duplicates — and What It Will Take to Fix It

Istanbul's municipal cultural archive holds somewhere in the region of 400,000 digitised photographs, maps, and planning documents — but a significant portion of that collection is redundant. The same image of, say, the Galata Bridge circa 1952, or an aerial survey of Karaköy from the 1970s, can appear under three or four separate catalogue entries, sometimes with conflicting metadata, sometimes stored across entirely different server environments maintained by different directorates within Istanbul Metropolitan Municipality.

The problem matters right now because the municipality, operating under Mayor Ekrem İmamoğlu's CHP administration, has committed to making its digital heritage collection publicly accessible via a unified portal before the end of 2026. That deadline is pressing. A city preparing to assert its cultural identity — particularly as central government pressure on the municipality continues — cannot afford an archive that undermines its own credibility through disorganisation.

How the Duplication Problem Built Up Over Thirty Years

The roots of the crisis go back to the early 1990s, when Istanbul's first digitisation efforts were piecemeal and departmental. The Istanbul Metropolitan Municipality's Directorate of Cultural Heritage and the separate Atatürk Library on Millet Caddesi in Fatih each began scanning analogue collections independently, with no shared taxonomy and no cross-referencing protocol. When the national SALT Research archive, based in Beyoğlu, digitised its own considerable holdings of Ottoman-era photographs in the 2000s, a third layer of parallel cataloguing emerged — one that overlapped substantially with what the municipality already held.

The problem compounded during the post-2010 period, when multiple EU-funded heritage digitisation grants flowed into Turkish cultural institutions. Each grant came with its own deliverables, its own metadata standards, and its own storage infrastructure. The Istanbul Development Agency, known as İSTKA, administered several of these programmes between 2011 and 2018, and the outputs were not always integrated into a central repository. Files were duplicated simply because no single body had authority — or budget — to enforce a unified standard.

Then came the 2023 Kahramanmaraş earthquake. The disaster accelerated emergency digitisation efforts across Türkiye, as institutions scrambled to create backup copies of at-risk physical materials. Istanbul's archives absorbed additional scanned material rapidly, and in the urgency of that period, deduplication checks were largely skipped.

What a Fix Actually Requires

Deduplication at this scale is not a simple software task. Image deduplication tools can catch identical binary files, but archival photographs scanned at different resolutions, with different colour profiles, or from different physical copies of the same print will not register as matches algorithmically. Human curatorial review is unavoidable for a meaningful portion of the collection.

The Atatürk Library, which holds more than 1.2 million items in its physical collection and has been expanding its digital reading room since 2021, is understood to be one of the institutions involved in discussions about a unified platform. The Istanbul Metropolitan Municipality's own BIMTAS technology subsidiary has the infrastructure capacity to host a consolidated archive, having already managed large-scale data migration projects for the municipality's transport and planning systems.

The practical implication for researchers, journalists, and the public is straightforward: until the deduplication work is complete, anyone using the municipal digital archive risks citing or reproducing an image under incorrect provenance data. A photograph attributed to 1930s Beyoğlu may actually be a scan of a later reproduction. Dating errors embedded in duplicate entries have propagated into academic papers and news publications already.

The municipality has indicated it intends to publish a revised catalogue architecture in the fourth quarter of 2026, ahead of the public portal launch. Whether the timeline holds will depend partly on budget — digital archiving work of this complexity typically runs to several million lira in staff and technical costs — and partly on whether the various institutions holding parallel collections agree to merge under a single governance structure, which has proved difficult to negotiate in the past. The history of how Istanbul arrived at this point is, in the end, a story about good intentions, institutional fragmentation, and the cost of deferring the unglamorous work of data hygiene.