How Istanbul's Streets Lost Their Faces: The Long Road to a Duplicate Image Crisis

Istanbul's official image archive contains at least three separate photographs of the same cracked wall on Balat's Vodina Caddesi, each catalogued under a different neighbourhood code, a different date, and — in one case — a different district entirely. That single example, drawn from an internal audit circulated among Istanbul Metropolitan Municipality departments earlier this year, captures a problem that has quietly metastasised across every digital platform the city uses to document itself.

The issue matters right now because two overlapping pressures have converged. Post-earthquake urban survey work, accelerated after the February 2023 Kahramanmaraş disaster, flooded municipal servers with hundreds of thousands of new field photographs. Simultaneously, the city's ongoing transformation of former industrial waterfronts — Galataport opened to cruise traffic in 2021, and Haydarpaşa's redevelopment remains a rolling controversy on the Asian shore — has generated competing visual records from contractors, municipal teams, and heritage watchdogs, all cross-uploading to shared drives with no unified tagging standard.

A Patchwork of Databases and Who Built Them

The roots of the problem stretch back to the late 1990s, when Istanbul's 39 districts began building their own digital image libraries independently. Kadıköy Municipality launched one of the earliest local photo repositories in 1998 as part of a European Union–funded urban renewal pilot. Beşiktaş followed within two years. By the time the metropolitan authority attempted to consolidate these libraries under a single content management system in 2014, the legacy files already numbered in the millions, each carrying metadata formatted differently depending on which vendor the individual district had hired.

That 2014 consolidation project, contracted through the Istanbul Planning Agency's predecessor body, was never fully completed. A follow-up audit in 2019 found that roughly 34 percent of images transferred into the central repository carried duplicate or near-duplicate identifiers — same subject, different file name, different GPS tag. The figure comes from a summary published by the İBB's information technology directorate, though the full audit document has not been released publicly. Heritage preservation groups, including the Çekül Foundation, which has worked on documentation projects in the historic peninsula since the 1990s, have flagged the mislabelling problem in correspondence with municipal planners, according to accounts reported by Turkish urban planning journals.

The earthquake risk dimension adds another layer of urgency. Building inspection teams deployed to Fatih, Zeytinburnu, and Avcılar — all districts sitting on high-risk soil zones identified by the Kandilli Observatory — photographed tens of thousands of structures between March 2023 and December 2025. Field teams frequently used personal smartphones alongside official cameras, then uploaded images to multiple platforms: the national AFAD damage registry, the İBB structural survey portal, and in some cases WhatsApp group archives later transferred to USB drives. When engineers revisit a specific building at, say, Koca Mustafapaşa Caddesi in Fatih, they may encounter four versions of the same facade shot, none clearly marked as superseded.

What a Fix Actually Requires

The technical solution is not exotic. Perceptual hashing — a method that generates a fingerprint from an image's visual content rather than its file metadata — can identify near-duplicates across large archives at relatively low cost. Several European cities, including Amsterdam and Vienna, have deployed similar systems to clean municipal heritage databases. Istanbul's challenge is institutional, not technological: any deduplication effort requires buy-in from dozens of departments that have spent years treating their own image libraries as proprietary resources.

The İBB's digital transformation unit published a procurement notice in March 2026 seeking vendors for a city-wide media asset management platform, with a submission deadline of 30 April 2026. Whether a contract has been awarded has not been confirmed in public records as of this writing. Heritage campaigners in Balat and Fener, where a UNESCO-adjacent buffer zone means documentation accuracy carries legal weight, say they will be watching closely. For now, the cracked wall on Vodina Caddesi remains catalogued three times over — a small, concrete symbol of what happens when a city photographs itself faster than it can remember what it has already seen.