Istanbul's Digital Archives Are Riddled With Duplicate Images — Officials and Experts Are Finally Talking About It

Istanbul's municipal and academic institutions are sitting on digital archives inflated by thousands of duplicate photographs — redundant files that slow databases, distort cultural inventories, and, in at least one documented case, led planners to miscount the number of surveyed heritage structures along the Golden Horn waterfront. The problem has been known for years. What's new is that officials are now openly acknowledging it.

The timing matters. The Istanbul Metropolitan Municipality (IBB) has been expanding its digital infrastructure since 2023, partly in response to data management gaps exposed by the Kahramanmaraş earthquake response, when fragmented records hampered damage assessment in vulnerable city districts. That push has forced archivists and IT departments to confront backlogs of untagged, duplicated image files across multiple platforms — a mundane but consequential administrative failure that is now feeding into debates about how the city documents itself for both planning and posterity.

Where the Problem Shows Up

Two institutions have become focal points in internal discussions. The first is the Istanbul Research Institute, based in the Beyoğlu district on İstiklal Caddesi, which manages one of the city's most extensive photographic collections covering Ottoman-era and early Republican Istanbul. Staff there have been working since early 2025 to implement automated deduplication tools across a collection that, by the institute's own public estimates, runs to several hundred thousand digitised images. The second is the urban documentation unit within IBB's Directorate of Historic Environment, which oversees photographic records tied to planning permits and heritage site assessments across neighbourhoods including Fatih, Eyüp, and Üsküdar.

Experts in digital archiving describe the Istanbul situation as typical of large municipal systems that digitised rapidly in the 2010s without standardised metadata protocols. When photographs are uploaded from multiple field teams covering the same street — say, a survey of Balat's coloured rowhouses or the yalıs along the Bosphorus — identical or near-identical images frequently enter the system under different file names and reference numbers. The result is an archive that looks comprehensive but contains significant internal noise.

Specialists in the field point to a practical consequence: when duplicate images are tagged to heritage site records, automated counting tools can generate inflated tallies of surveyed structures, creating a false impression of documentation coverage. This is particularly sensitive in Istanbul, where the Bosphorus Development Zone and ongoing disputes over construction permits in areas like Arnavutköy and Beykoz depend partly on how thoroughly existing structures have been catalogued.

What Officials and Specialists Are Saying

IBB has not issued a formal public statement on the deduplication effort, but the municipality's 2025 annual technology report — published on the IBB portal in March 2026 — references an ongoing audit of visual asset databases and a target to reduce redundant file storage by 30 percent across core planning systems before the end of 2026. No budget figure for the project is cited in that document.

At the academic level, staff at Istanbul Technical University's (ITÜ) Urban and Regional Planning department have described the duplicate image issue in conference presentations as a systemic challenge for cities undergoing rapid GIS integration. ITÜ held a workshop on urban data quality at its Taşkışla campus in Taksim in April 2026, where the problem of redundant visual records in heritage documentation was among the agenda items, according to the event programme published on the university's website.

The broader professional consensus, as reflected in those discussions, is that the fix is technical but not trivial. Perceptual hashing algorithms — software that identifies visually similar images even when file names differ — can automate much of the work, but human review remains necessary for photographs where slight differences in angle or lighting carry genuine documentary value. For a city whose photographic heritage spans the late Ottoman period through to drone footage of last year's construction controversies in Ataköy, getting that distinction right is not a minor concern.

The IBB audit is expected to produce interim findings by the end of the third quarter. Archivists at institutions with holdings tied to municipal planning records have been advised to flag duplicated entries in shared databases before that review concludes — a practical step that, if followed consistently across Fatih, Kadıköy, and the historic peninsula, could meaningfully clean up the documentary record Istanbul relies on to manage one of the world's most contested urban environments.