Prague's Digital Archive Reckoning: The Key Decisions Ahead on Duplicate Image Replacement

Prague's municipal digitisation drive has hit an awkward milestone. After years of scanning historical photographs, planning documents, and urban heritage records, the city's institutions are sitting on a growing backlog of duplicate images — redundant files clogging storage systems, confusing archivists, and in some cases causing errors in public-facing databases. The question now is not whether to act, but how, and who pays.

The issue has sharpened in 2026 because several major projects are converging at once. The Prague City Archive on Archivní Street in Žižkov is mid-way through a five-year digitisation programme that began in 2022. Meanwhile, the Institute of Planning and Development — known by its Czech acronym IPR Praha — has been building out its metropolitan digital map platform, which pulls from multiple municipal image databases. When duplicate records exist across both systems, errors propagate. A mislabelled photograph of a Holešovice warehouse from 1938, duplicated across three catalogues, can generate incorrect metadata in all three places simultaneously.

What the Duplication Problem Actually Looks Like

Duplicate image replacement is not simply a matter of deleting extra files. Archivists must verify which version of an image carries the correct metadata, check provenance, update cross-references in linked records, and then retire the redundant copies without breaking existing citation chains. For institutions like the National Technical Museum on Kostelní Street in Letná, which holds more than 1.2 million digitised items in its collections as of its most recent published figures, even a five percent duplication rate represents a significant remediation workload.

IPR Praha's open data portal, which went through a significant infrastructure upgrade in late 2024, currently hosts spatial and photographic data tied to planning applications across all 57 Prague administrative districts. Staff there have identified duplicate image clusters as one of the top three data quality issues requiring resolution before the platform's next public release, scheduled for the fourth quarter of 2026. The remediation work involves both automated deduplication tools and manual review — a combination that increases both cost and timeline.

The City of Prague's 2026 IT budget, approved by the City Council in December 2025, allocated roughly 340 million Czech crowns to digital infrastructure across all departments. How much of that figure reaches archive remediation specifically is still being negotiated between individual institutions and the city's Department of Information Technology. Several smaller district offices, including those covering Praha 7 and Praha 3, have flagged that their local digitisation projects lack the staffing to carry out manual review at scale.

The Decisions That Will Shape the Next 12 Months

Three choices will define how this gets resolved. First, whether Prague adopts a centralised deduplication platform or lets each institution manage its own cleanup — a decision that carries real cost implications either way. Centralised tools require procurement and integration work; decentralised approaches risk inconsistent standards that generate new duplication down the line.

Second, the city must decide what to do with images where no clear canonical version exists — photographs scanned twice from different physical copies, both with partial damage. Retiring either copy risks losing visual information. Retaining both defeats the purpose of the exercise. The Prague City Archive has been developing internal protocols for exactly these cases, but those protocols are not yet standardised across institutions.

Third, and most practically, institutions need to agree on a shared metadata schema so that replacement images slot cleanly into existing catalogue structures. Without that agreement, even a successful deduplication exercise can leave downstream databases inconsistent.

Archivists and IT managers across the city are expected to meet under the auspices of the Prague Digital Heritage Working Group — a body convened informally since 2023 — before the end of September 2026. That meeting will likely be the first real test of whether a coordinated city-wide approach is politically achievable, or whether each institution continues to manage the problem alone. Either way, residents and researchers who rely on Prague's public image archives should expect a period of intermittent access disruptions as cleanup work begins in earnest later this year.