Istanbul's Photo Archive Crisis: The Hidden Scale of Duplicate Images Swamping City Records

Istanbul's digital infrastructure is sitting on a problem that few officials publicly acknowledge: duplicate images have quietly consumed an estimated 30 to 40 percent of usable storage across municipal photo archives, heritage documentation systems and commercial property databases. The figure, drawn from storage audit benchmarks applied to mid-sized urban government systems in comparable European and Middle Eastern cities, reflects a pattern that Istanbul's own institutions are not immune to — and the costs are measurable.

The issue matters now for a specific reason. The Istanbul Metropolitan Municipality, operating under Mayor Ekrem Imamoğlu's administration, has been pushing an accelerated digitisation drive since 2024, scanning tens of thousands of documents, architectural records and street-level photographs as part of urban resilience planning tied to post-earthquake preparedness protocols. Following the catastrophic February 2023 Kahramanmaraş earthquakes, municipalities across Turkey were pressed to build faster, more accessible digital inventories of building stock and infrastructure. Speed, in that context, often came at the cost of deduplication discipline.

What the Numbers Actually Look Like

Storage waste from duplicate images is not trivial. In large-scale digitisation projects, industry-standard audits consistently find that between 25 and 45 percent of ingested image files are either exact duplicates or near-duplicates — the same photograph uploaded multiple times under different file names, or near-identical frames pulled from drone surveys with only marginal pixel variation. At Istanbul's KUDEB, the Historic Buildings Inspection and Repair Unit operating under the municipality, surveyors document thousands of heritage structures annually across districts like Fatih, Beyoğlu and Üsküdar. A single site inspection commonly generates 80 to 120 photographs. When those files feed into multiple databases — a departmental server, a shared cloud archive, and a project-specific folder — triplication of content becomes routine rather than exceptional.

The real-estate sector compounds the picture. On platforms like Sahibinden.com and Emlakjet, property listings in high-turnover corridors such as Kadıköy's Moda neighbourhood and the Boğaziçi waterfront in Beşiktaş frequently carry duplicate or near-duplicate listing photographs that survive across relisted properties for months. A 2024 industry analysis of Turkish property portals — cited by the Turkish Real Estate Information System, TABİS — flagged that redundant imagery inflated effective database size by roughly 28 percent, slowing search indexing and degrading recommendation algorithms.

The cost is not abstract. Cloud storage pricing in Turkey, denominated in US dollars given lira volatility, means that organisations paying for AWS or Azure capacity are effectively paying hard currency for redundant files. At current enterprise storage rates of approximately $0.023 per gigabyte per month on standard tiers, a municipal archive holding 10 terabytes of which 35 percent is duplicate content is spending the equivalent of roughly $966 annually on files that serve no informational purpose. Scale that across a dozen departments in a city of 16 million people and the waste becomes a serious line item.

The Path Forward for Istanbul's Institutions

Deduplication is a solved technical problem. Perceptual hashing algorithms — tools that generate a fingerprint for each image and flag near-identical matches regardless of file name or metadata — can process large archives at low cost. Several Istanbul-based technology firms operating out of the Teknopark İstanbul campus on the Sabancı University grounds in Tuzla have developed localised versions of these tools tailored to Turkish-language metadata environments.

The practical barrier is institutional will and workflow redesign. Archivists at the Istanbul Archaeological Museums in Sultanahmet and surveyors at KUDEB both operate under upload procedures that pre-date modern deduplication awareness. Retrofitting those pipelines requires a one-time audit investment and revised intake protocols — not a major capital project.

Cities that have run systematic deduplication programs — Lisbon's municipal archive completed one in 2023, reducing its photo database by 31 percent — report that cleaned datasets become faster to search, cheaper to host and more reliable for AI-assisted analysis. Istanbul's institutions, already under pressure to modernise in the shadow of seismic risk and a demanding tourism season that brought over 20 million visitors in 2025, have a clear practical case for moving on this before the next digitisation cycle begins.