Istanbul's Duplicate Image Problem: Key Decisions Ahead for the City's Visual Archive

Istanbul's municipal digital archive holds a problem hiding in plain sight. Tens of thousands of duplicate photographs — accumulated through years of overlapping digitisation drives, tourism campaigns, and heritage documentation projects — are now straining storage systems and muddying the official visual record of one of the world's most photographed cities. The question of what happens next is no longer an administrative footnote; it is a decision with consequences for urban planning, earthquake preparedness, and the city's cultural memory.

The timing matters. Istanbul Municipality's ongoing earthquake resilience programme, which accelerated following the February 2023 Kahramanmaraş disaster, relies heavily on accurate photographic documentation of at-risk buildings across districts including Fatih, Zeytinburnu, and Avcılar. When duplicate images flood a database — sometimes three or four near-identical shots of the same crumbling Ottoman-era structure on, say, Küçük Ayasofya Caddesi — field engineers and urban planners cannot quickly establish which image is the most recent or the most structurally revealing. The stakes are not abstract.

The Scale of the Backlog

Istanbul Metropolitan Municipality's directorate responsible for urban information systems — İBB's Coğrafi Bilgi Sistemleri birimi — has been running a consolidation review since at least early 2025, according to publicly available municipal budget documents. The Heritage Documentation Unit attached to the Fatih district municipality separately maintains photographic records of the roughly 2,500 registered historical structures within its boundaries, a figure cited in the district's own published conservation plan. Cross-referencing those two databases alone has revealed significant duplication, though the exact count remains an internal working figure.

The Istanbul Metropolitan Municipality's digitisation contracts, several of which were awarded to local technology firms in the Maslak business district, specified image deduplication protocols. Whether those protocols were consistently enforced across subcontractors is among the questions now under internal review. No formal finding of non-compliance has been publicly released.

Tourism adds another layer of complexity. The Culture and Tourism Directorate uses a separate photographic library to supply images for campaigns promoting sites from the Grand Bazaar to the Galata Tower and the Süleymaniye Mosque. That library, maintained partly in partnership with the Turkish tourism promotion agency, has grown to an unwieldy size over repeated annual campaign cycles. Industry benchmarks suggest municipal image libraries of comparable cities — Barcelona's Arxiu Fotogràfic, for instance — require active deduplication reviews every 18 to 24 months to remain operationally clean.

What Comes Next and Who Decides

Three decisions are now sitting on the table, each with its own deadline pressure. First, the municipality must decide by the end of the third quarter of 2026 whether to procure a dedicated AI-assisted deduplication tool or to expand the contract scope of its existing GIS vendor. Budget sessions at İBB for fiscal year 2027, which begin in September, will effectively set that choice in stone.

Second, there is the question of deletion versus archiving. Some duplicate images — particularly those showing buildings that have since been demolished or damaged — have documentary value even if they are technically redundant. Urban historians at Istanbul Technical University's Faculty of Architecture have long argued for a tiered retention policy rather than blanket deletion, a position consistent with international archival standards but one that requires more storage capacity, not less.

Third, and most politically charged given the ongoing friction between the CHP-led metropolitan municipality and the national government, is the question of which authority controls the master archive. Several of Istanbul's district municipalities, which answer to AKP-appointed administrations, maintain parallel photographic records that do not automatically sync with İBB's central systems. Resolving that fragmentation requires inter-institutional cooperation that has, in recent years, been in short supply.

For ordinary Istanbullus, the practical implications arrive quietly but consequentially. Inaccurate or outdated building photographs can delay demolition permits for earthquake-risk structures under the urban transformation law known as Kentsel Dönüşüm. Residents of Zeytinburnu and Bağcılar — two districts with some of the city's highest concentrations of legally designated risky buildings — have the most to lose if the archive problem is left unresolved heading into the 2027 planning cycle.