How Istanbul's Image Archives Ended Up a Maze of Duplicates — and Why Fixing It Now Matters

Istanbul's sprawling inventory of urban imagery — spanning heritage site surveys, earthquake-risk assessments, and tourism promotion libraries — has accumulated tens of thousands of duplicate photographs, maps, and architectural scans, with no single authority yet holding a clean, deduplicated master archive. The problem is structural, years in the making, and it is now colliding with urgent deadlines set by post-2023 seismic retrofit programmes and European Capital of Smart Tourism certification requirements.

The collision matters because decisions cost money. When engineers, planners, and communications teams pull conflicting image files, they lose time reconciling versions, occasionally building reports on outdated survey photographs. In a city where the Istanbul Metropolitan Municipality — İstanbul Büyükşehir Belediyesi, or İBB — runs parallel digital platforms alongside national bodies such as the Directorate General of Foundations (Vakıflar Genel Müdürlüğü), duplication was almost inevitable.

How the Copies Piled Up

The root of the problem stretches back to the early 2010s, when the Ministry of Culture and Tourism launched digitisation grants encouraging district municipalities, universities, and heritage foundations to photograph historical sites independently. Fatih municipality catalogued the Byzantine and Ottoman structures along the old city walls. Beyoğlu district shot hundreds of Pera-era apartment blocks on İstiklal Caddesi. Kadıköy's cultural office documented the Asian shore's Art Nouveau market buildings. Each institution used different metadata standards, different file naming conventions, and different storage vendors. Nobody built a crosswalk between them.

Then came the pandemic. Between 2020 and 2022, emergency funding pushed a second wave of digitisation — this time focused on earthquake vulnerability mapping across at-risk districts including Avcılar, Bağcılar, and Zeytinburnu. Field teams photographed the same crumbling masonry apartment blocks multiple times, filing images into at least three separate government platforms: the İBB's own AKOM disaster management system, the Disaster and Emergency Management Authority (AFAD) national portal, and Boğaziçi University's Kandilli Observatory disaster database. Analysts who later tried to cross-reference damage predictions found the same building photographed from nearly identical angles under different file IDs, assigned different risk codes in different systems.

The 2023 Kahramanmaraş earthquakes accelerated the reckoning. Istanbul planners scrambling to update preparedness models pulled image sets that turned out to be years old — in some cases, photographs of buildings already demolished. The administrative and financial cost of auditing that material, while not yet a matter of public record, prompted a working group under the İBB's Directorate of Urban Transformation to begin a formal deduplication project in late 2024.

Where the Process Stands Now

That working group, based at the İBB's headquarters in Saraçhane, has been piloting a hash-based image matching system across a test corpus drawn from the Sultanahmet conservation zone and the Haydarpaşa train station heritage files. The pilot covers roughly 40,000 image assets, according to a project outline posted to the İBB's open data portal in March 2025 — a fraction of the estimated total holdings across all linked institutions.

Budget is a constraint. The İBB's 2025 capital technology budget was set at 2.1 billion lira, a figure the municipality published in its annual report, but urban transformation digitisation competes with infrastructure, transport software, and earthquake resilience hardware for those funds. Turkish lira inflation, which has kept construction and technology procurement costs elevated well above pre-2021 levels, makes multi-year archiving contracts difficult to price.

For residents, architects, and journalists, the practical upshot is simple: any image pulled from a municipal portal today should be treated as potentially one of many versions. Anyone filing documentation for a heritage restoration permit through the Istanbul Regional Council for the Protection of Cultural and Natural Heritage — which sits offices near the Sultanahmet district — should request metadata verification on any photograph they submit or receive.

The deduplication working group is expected to publish a progress report by the end of 2026. Until then, the city's visual memory remains, in places, an echo chamber of itself.