Melbourne's Duplicate Image Problem: How the City Stacks Up Against Amsterdam, Toronto and Seoul

Melbourne's public digital archives are carrying a weight problem. Across repositories managed by the City of Melbourne, the State Library Victoria on Swanston Street, and the Public Record Office Victoria in North Melbourne, archivists and digital asset managers have been quietly grappling with a phenomenon that has quietly inflated storage costs and degraded search quality: duplicate images filed under different metadata tags, different accession numbers, or simply uploaded twice during rushed digitisation drives.

It is not a glamorous crisis. But for institutions trying to make their collections genuinely searchable — and for ratepayers funding the server bills — it matters considerably right now, as councils and cultural bodies globally rush to meet open-access mandates with leaner budgets than they had even three years ago.

What Melbourne Is Actually Doing

The State Library Victoria launched its Digital Collections redevelopment in stages between 2022 and 2025, migrating tens of thousands of photographs, maps and ephemera into a unified platform. That migration, by the library's own public documentation, surfaced significant duplication problems: items scanned in the 1990s under one cataloguing regime had often been rescanned in higher resolution in the 2010s without the originals being deprecated. The result is a collection where a single image of Flinders Street Station, for instance, might appear under three separate catalogue entries — each with slightly different descriptive tags, each consuming storage and each capable of returning in a search result.

The City of Melbourne's open data portal, which hosts thousands of images of public infrastructure and streetscapes from Docklands to Carlton, does not currently publish a deduplication policy. A review of the portal's terms and metadata documentation, publicly accessible as of this week, shows no formal schedule for periodic duplicate audits.

By contrast, Amsterdam's Stadsarchief — the city's municipal archive — completed a full deduplication pass on its 750,000-image digitised photograph collection in 2023, using perceptual hashing software to flag near-identical images regardless of file format or resolution. The archive published a methodology note in February 2024 describing the process, and its search results are now structured to surface the highest-resolution version of a duplicate set while retaining the others as hidden alternates. Toronto's City Archives undertook a comparable process as part of its 2024–2026 digital transformation strategy, with the city allocating CAD $1.4 million across two financial years specifically for metadata remediation.

Seoul and the Machine-Learning Shortcut

Seoul Metropolitan Government has gone furthest, deploying a machine-learning deduplication system across its e-government image libraries in late 2024. The system operates on a 30-day rolling audit cycle and automatically flags duplicates for human review rather than auto-deleting them — a safeguard that Melbourne's digital archivists, speaking in general terms at a February 2026 panel at RMIT University on Swanston Street, flagged as best practice for any institution that cannot afford false-positive deletions of historically significant material.

Melbourne's institutions are not without resources. Public Record Office Victoria received a $6.3 million state government allocation in the 2025–26 Victorian Budget to continue digitisation of physical records. Whether a portion of that funding is directed toward deduplication remediation is not specified in Budget Paper No. 3, which outlines agency outputs without granular line-item detail at that level.

The practical cost of inaction is measurable. Cloud storage for cultural institutions on Australian government-tendered contracts typically runs between $0.023 and $0.04 per gigabyte per month, depending on tier and redundancy requirements. An archive carrying 20 per cent duplicate content — a figure consistent with rates reported in overseas case studies from Amsterdam and Toronto — is burning money every month on images nobody needs stored twice.

For Melbourne, the path forward is reasonably clear even if the timeline is not. Perceptual hashing tools are open-source and well-documented. The Victorian Government's Digital Strategy, updated in 2024, explicitly calls for agencies to minimise unnecessary data storage. What is missing, so far, is a coordinated mandate that brings the City of Melbourne's open data portal, Public Record Office Victoria and the State Library into a single deduplication framework — the kind of whole-of-government approach that Amsterdam and Seoul have already demonstrated is achievable within a two-year window and a defined budget.