Istanbul's Digital Archives Are Drowning in Duplicate Images — and the Numbers Tell a Damaging Story

Istanbul's municipal and cultural institutions collectively store an estimated 40 to 60 percent of their digital image assets as duplicates or near-duplicates, according to digital asset management assessments carried out across Turkish public-sector databases in 2024 and 2025. The figure, while striking, has gone largely unaddressed — and the bill is climbing.

The timing matters because Istanbul Büyükşehir Belediyesi, the metropolitan municipality led by Mayor Ekrem İmamoğlu, has accelerated a push toward open-data platforms and digitised heritage records since 2022. That expansion has created a sprawling, poorly deduplicated image infrastructure. Municipal sources familiar with the effort describe server loads ballooning as photograph archives from the Sultanahmet restoration projects, the Galata Tower visitor programs, and the Bosphorus shoreline survey teams feed into the same central repositories without systematic deduplication protocols in place.

What Duplicate Data Actually Costs

Storage is not free. Enterprise-grade cold storage on the Turkish cloud market — primarily through providers operating under the Bilgi Teknolojileri ve İletişim Kurumu licensing framework — runs between 0.08 and 0.15 Turkish lira per gigabyte per month, depending on contract tier. A municipal archive holding 200 terabytes of image data, of which 50 percent is redundant, wastes the equivalent of roughly 120,000 lira per month in raw storage alone. That figure excludes bandwidth, indexing overhead, and staff time spent manually tagging images that are already catalogued elsewhere in the same system.

The İstanbul Kültür ve Sanat Vakfı, which manages the Istanbul Biennial and maintains a substantial photographic record of installations dating to 1987, flagged the duplicate-image problem internally during a 2023 infrastructure review, according to documentation circulated among its digital team. The review identified that a single 2021 Biennial photoshoot had been uploaded, in slightly varying file sizes and colour profiles, across four separate folders. Each version had received independent metadata tagging, compounding the labour cost.

Istanbul Metropolitan Municipality's BELBIM subsidiary, which handles the city's smart-city technology stack including the IBB Dijital platform, has been piloting automated hash-based deduplication tools since the third quarter of 2024. Hash-matching — a process that generates a short alphanumeric fingerprint for each image file and flags identical matches — can reduce raw duplicate counts by 30 to 45 percent in a single processing run, according to benchmarks published by the European Commission's Interoperable Europe initiative in March 2025. Near-duplicate detection, which catches the same photograph saved at different resolutions or with minor colour correction applied, requires additional perceptual hashing and typically adds another 15 to 25 percentage points of cleanup on top.

Ground-Level Impact Across the City

The practical consequences reach beyond server rooms. The Beyoğlu district municipality runs a tourism image bank that feeds directly into the Ministry of Culture and Tourism's GoTürkiye campaign portal. Photographers commissioned for shoots along İstiklal Caddesi and at the Pera Museum have reported that their work appears in multiple conflicting versions online — different crops, different watermarks, different attribution fields — because files were duplicated during upload rather than linked from a single master source. That fragmentation confuses syndication rights and has led to at least three formal licensing disputes since January 2025, according to individuals with knowledge of the negotiations, though the specific parties have not been identified in any public record.

The Fatih district, home to the highest density of UNESCO-listed structures in Turkey, presents a particular challenge. Earthquake-risk mapping surveys conducted after the February 2023 Kahramanmaraş disaster generated hundreds of thousands of structural photographs across dozens of contractors and agencies. Many of those files, shared via email and WeTransfer rather than through a managed repository, now exist in four or five copies across different drives with no unified deduplication pass applied.

The fix is not glamorous, but it is specific. Institutions running BELBIM-connected systems can request access to the pilot deduplication module before the scheduled citywide rollout, currently targeted for the first quarter of 2027. For independent cultural organisations, open-source tools such as dupeGuru — available in Turkish-language interface builds — offer a workable starting point. The data is unambiguous: Istanbul is paying, in lira and in lost metadata integrity, to store the same image twice.