How Istanbul's Historic Image Archives Ended Up Full of Duplicates — and Why Fixing It Now Matters

Istanbul's municipal digital archive holds tens of thousands of photographs, maps, and scanned documents — and for years, nobody could say with confidence how many were genuine unique records versus redundant copies filed twice, three times, or more under different catalogue numbers. That uncertainty, long tolerated inside the bureaucracy of the İstanbul Büyükşehir Belediyesi, or IBB, is now driving a formal deduplication effort whose scope has surprised even the officials overseeing it.

The problem did not arrive overnight. It accumulated across roughly two decades of digitisation drives that were never fully coordinated. When IBB launched its first systematic push to scan physical records in the early 2000s, the work was split across departments — urban planning, heritage conservation, the Atatürk Library on Beyazıt Square, and the separately administered district municipalities. Each unit ran its own naming conventions and storage systems. When those collections were eventually merged into a central repository, duplicates were baked in from the start.

Three Waves of Digitisation, Three Sets of Problems

The situation grew more complicated after 2012, when IBB accelerated archiving ahead of Istanbul's candidacy for various UNESCO and European heritage programmes. Contractors brought in to digitise collections at the Istanbul Archaeological Museums in Sultanahmet and at the Beyoğlu municipality offices worked under tight deadlines. Quality control was secondary to volume. Files were saved in multiple formats — TIFF, JPEG, and later PDF — and each format version was sometimes registered as a distinct catalogue entry rather than a derivative of the same source image.

A third wave came after the 2023 Kahramanmaraş earthquakes, when emergency protocols prompted rapid offsite backup of city records. Fearful of data loss, archivists copied entire folders to new servers without first auditing what was already there. By some internal estimates circulated within IBB's technology directorate — figures that have not been made public — duplicate entries may account for between 20 and 35 percent of the total image inventory. The Daily Istanbul was not able to independently verify those figures from public documents.

The political backdrop matters too. Since Ekrem İmamoğlu's return to active municipal leadership following extended legal disputes with the central government, IBB has leaned into transparency projects as a way of demonstrating competent governance. A clean, searchable archive is a small but legible symbol of that ambition. The deduplication project, run out of IBB's digital transformation unit, uses automated hash-matching software to flag identical files and presents human reviewers with side-by-side comparisons before any deletion is authorised. Nothing is erased without a secondary sign-off.

What a Cluttered Archive Actually Costs

The practical consequences of duplicate-heavy archives are more concrete than they might sound. Researchers at Istanbul University's Faculty of Architecture, which relies on IBB image databases for urban morphology studies along the Golden Horn and in districts like Fatih and Eyüpsultan, have described spending significant time identifying and discarding repeat images before usable datasets can be assembled — though the university has not published a formal study quantifying that burden. Storage costs for the municipal server infrastructure, which IBB moved to a data centre in the Mahmutbey logistics zone in 2022, are real and recurring.

Internationally, cities that have gone through comparable clean-up exercises — Amsterdam's municipal archive completed a major deduplication review in 2021, for instance — found that removing redundant files reduced active storage loads by 15 to 25 percent while improving search accuracy for public-facing portals. Istanbul's archive team is using those cases as informal benchmarks.

The practical takeaway for anyone who uses IBB's public image portal, accessible through the municipality's official website, is that search results should become more reliable as the review proceeds. Institutions like the Research Centre for Islamic History, Art and Culture on Yıldız Caddesi in Beşiktaş, which draws on municipal photograph collections regularly, will be among the first to notice the difference. IBB has indicated the first phase of the deduplication review is scheduled for completion before the end of 2026, though no specific date has been formally announced.