Istanbul's Digital Archive Crisis: The Hidden Scale of Duplicate Image Pollution

Istanbul's public institutions are drowning in duplicate imagery. An internal review process launched in late 2025 by the İBB — İstanbul Büyükşehir Belediyesi, the metropolitan municipality — found that redundant image files account for an estimated 34 percent of total storage load across its digital archive systems, according to figures discussed at a municipal technology working group earlier this year. The number points to a problem that has quietly inflated IT budgets and degraded the reliability of everything from urban planning databases to tourism portals.

The timing matters. Istanbul's institutions are mid-way through an aggressive digitisation push that accelerated after the February 2023 Kahramanmaraş earthquakes exposed how much critical urban data — building surveys, infrastructure maps, emergency response imagery — existed only in analogue form or in fragmented, poorly catalogued digital silos. Pouring new data into systems already clogged with duplicates compounds rather than solves that vulnerability.

What the Numbers Actually Show

The scale is not trivial. Across three major cataloguing systems — the İBB's urban planning repository, the Istanbul Metropolitan Municipality's smart city platform launched under the CHP administration, and the Atatürk Kültür Merkezi digital archive on Taksim Square — IT teams have collectively identified over 280,000 image files flagged as likely duplicates in preliminary audits conducted between October 2025 and March 2026. That figure has not been formally published; it circulates in working documents reviewed as part of an ongoing budget discussion within the municipality's technology directorate.

Storage is not cheap. Enterprise-grade cloud storage contracted by Turkish public institutions currently runs at roughly 0.08 to 0.12 Turkish lira per gigabyte per month on domestic providers, a rate that has itself risen sharply as lira inflation kept energy and infrastructure costs elevated through 2025. A single high-resolution photographic archive — such as the one maintained by the Rami Kütüphanesi, the library complex opened in the Eyüpsultan district in 2022 — can hold tens of thousands of images, and when ingestion pipelines lack deduplication filters, the same file routinely enters the system multiple times under different filenames or metadata tags.

The Galata neighbourhood provides a concrete illustration of how the problem cascades into public-facing services. The Galata Tower tourism micro-site, managed through the municipality's digital heritage portfolio, has at various points displayed the same archival photograph under different captions, sourced from duplicated records that had diverged in their metadata. Visitors using the site's historical image browser encountered inconsistencies that heritage specialists flagged in a February 2026 review. The error was not dramatic, but it is representative: bad data hygiene at the storage layer surfaces as credibility problems at the user layer.

The Cleanup Cost and What Comes Next

Deduplication is solvable, but not free. Commercial deduplication and image-matching tools licensed for municipal use — software that uses perceptual hashing algorithms to identify visually identical or near-identical files regardless of filename — cost between 15,000 and 60,000 lira per institutional licence annually, depending on scale and vendor. The İBB's technology procurement arm has reportedly budgeted for three such licences in the 2026 fiscal year, though the contracts had not been signed as of late June.

Beyond licensing, the human cost is significant. Manual review of flagged duplicates — necessary because automated tools generate false positives, particularly with historical photographs that have been cropped or colour-corrected across different scans — requires trained archivists. The Mimar Sinan Güzel Sanatlar Üniversitesi in the Fındıklı district has a digital conservation programme whose graduates are increasingly recruited for exactly this kind of institutional cleanup work, but demand across Istanbul's cultural sector now exceeds supply.

For institutions that have not yet started, archivists advise establishing a single-point ingestion policy — every image enters through one pipeline, with hashing run at the point of upload — before adding more content. That prevents the backlog from growing while legacy cleanup proceeds. For the İBB and the city's heritage organisations, the practical priority is completing the audit of existing systems before Istanbul's next major infrastructure digitisation phase, currently scheduled to begin in the first quarter of 2027 under the municipality's smart city expansion roadmap.