Istanbul's Digital Archives Are Drowning in Duplicate Images — and the Numbers Reveal Why

At least 4.2 million image files held across Istanbul Metropolitan Municipality's digital infrastructure are estimated to be exact or near-exact duplicates, according to an internal audit circulated among IT procurement teams earlier this year. The finding has set off a quiet but consequential scramble inside municipal technology departments to clean house before a new unified public records portal is scheduled to go live in the fourth quarter of 2026.

The problem is not unique to city hall. It mirrors a crisis unfolding across Turkey's major cultural institutions as decade-old analogue collections get scanned, uploaded — and frequently re-uploaded — without consistent deduplication protocols in place. In Istanbul, where digitisation spending has accelerated since the 2023 Kahramanmaraş earthquakes underscored just how fragile physical archives can be, the volume of redundant data has grown faster than the systems designed to manage it.

What the Storage Bills Actually Say

Redundant image storage is not an abstract IT headache. Each terabyte of enterprise-grade cloud storage costs municipal institutions roughly 180 to 220 Turkish lira per month at current market rates — a figure that has nearly tripled since 2021 as lira inflation compounded against dollar-denominated cloud contracts. The Istanbul Archaeological Museums, which holds one of the largest digitised artefact catalogues in the region with scans dating back to a 2014 UNESCO-backed indexing project, reportedly carries a duplicate rate of close to 30 percent across its photographic holdings, according to a procurement document reviewed by The Daily Istanbul. That means roughly three in every ten image files stored is redundant.

The Atatürk Cultural Centre on Taksim Square — reopened in 2021 after years of reconstruction — has built one of the city's more ambitious digital content libraries, covering performance archives, architectural drawings, and event photography. Staff there have been piloting deduplication software since March 2026, targeting an estimated 600,000 flagged duplicate files in the performing arts photography catalogue alone. The software works by generating hash values — essentially a mathematical fingerprint — for each image, then cross-referencing the entire library for matches. Early results reduced raw storage demand by roughly 22 percent in a test batch of 80,000 files.

Across the Bosphorus in Kadıköy, the Moda neighbourhood branch of the İBB's municipal library network flagged a related problem in January: cataloguers scanning Ottoman-era maps of the Anatolian coastline had inadvertently created three separate scans of the same 1847 survey document across different project phases, each stored under a different file name and metadata tag. Multiply that kind of administrative duplication across 39 districts and hundreds of individual digitisation drives, and the aggregate waste becomes significant.

A City-Wide Fix Is Still Some Way Off

Turkey's national digital archive standards body, the Devlet Arşivleri Başkanlığı — the Directorate of State Archives — issued updated metadata guidelines in February 2026 requiring all public institutions to adopt SHA-256 file fingerprinting before submitting materials to central repositories. Istanbul's municipal IT directorate has until December 31, 2026 to bring its holdings into compliance. That deadline is what has focused minds at city hall.

For institutions that cannot afford enterprise deduplication tools, open-source alternatives are gaining ground. The Beyoğlu district cultural directorate began using an open-source pipeline in May that processes roughly 50,000 images per day on standard municipal server hardware. The approach is slower than commercial solutions but costs nothing in licensing fees — a meaningful consideration when IT budgets are being squeezed by the same inflationary pressures hitting storage contracts.

Archivists and IT managers working through the compliance window should document every active digitisation project now, tag files at the point of creation rather than retrospectively, and insist on a single master repository per institution before any new scanning drive begins. The December deadline is real. The costs of missing it — both financial and in terms of public access to Istanbul's irreplaceable historical record — are measurable, and they are growing.