Melbourne's duplicate image problem: how the city stacks up against Amsterdam, Toronto and Seoul

Melbourne City Council's digital archives team flagged the problem formally in late 2025: thousands of images stored across its public collections had been duplicated, mislabelled, or cross-posted without consistent metadata. The Docklands precinct redevelopment records alone contained more than 4,200 image files, with internal audits finding significant duplication rates across submissions from contractors and planning consultants. The council is not alone.

Across Australia's second-largest city, the issue has compounded quietly for years as institutions digitised physical collections rapidly during COVID-era closures and then continued uploading at pace without standardised deduplication protocols. The urgency now stems from two pressures converging at once: Victoria's housing density reform push is flooding local government planning portals with site photography and heritage documentation, and the State Government's broader data integrity agenda — tied to its Digital Victoria strategy — is demanding cleaner public records.

What Melbourne is actually doing

The City of Yarra became the first Melbourne council to trial automated deduplication software across its planning image database, beginning a pilot with its Collingwood and Richmond heritage overlay records in March 2026. The program uses perceptual hashing — a technique that detects visually identical or near-identical images even when file names differ — and has so far processed roughly 38,000 images, according to information published on the council's digital services update page in May 2026.

State Library Victoria, on Swanston Street, has run a parallel exercise across its Pictures Collection, one of the largest photographic archives in the Southern Hemisphere. Librarians there have been cross-referencing digitised items against the Trove national aggregator maintained by the National Library of Australia to identify records that appear in both repositories with conflicting attribution. The project, which began in January 2026, is scheduled for a first-stage completion by December 2026.

The CFMEU's Victorian construction branch has also emerged as an unlikely stakeholder. Worksafe Victoria documentation requirements for construction sites generate large volumes of site photography, and duplicated or incorrectly filed images have created administrative headaches during incident reviews. Industry groups representing builders operating along the Suburban Rail Loop corridor have raised the issue with the Department of Transport and Planning since early 2026.

How Melbourne compares globally

Amsterdam's municipal archive, the Stadsarchief, completed a three-year deduplication overhaul in 2024, clearing approximately 1.2 million duplicate records from its 750,000-image digitised collection — a project that cost the city roughly €2.1 million, according to a case study published by Europeana, the European digital heritage network. The Stadsarchief now uses a centralised ingest system that flags duplicates at the point of upload, before they enter the main database.

Toronto has taken a different path. The Toronto Public Library's digital collections team embedded deduplication checkpoints into its vendor contracts from 2023, effectively outsourcing the quality control to digitisation partners rather than running post-hoc clean-ups. Seoul's Metropolitan Archives went further, mandating a blockchain-based provenance trail for all incoming government image records from July 2025 — an approach that several Melbourne technologists have described publicly at events including the 2026 GovHack Melbourne regional finals in June as ambitious but expensive to replicate at local government scale.

Melbourne's approach is more fragmented than Amsterdam's centralised model and less contractually rigorous than Toronto's vendor-led system, but the City of Yarra pilot and the State Library project represent concrete progress where many comparable Australian cities — including Brisbane and Perth — have not yet moved beyond internal policy reviews.

For residents, the practical consequence is most visible in planning decisions. Duplicate or misattributed heritage images have in at least two documented Victorian Civil and Administrative Tribunal cases contributed to delays in heritage overlay determinations, with parties submitting conflicting photographic evidence that turned out to reference the same building photographed at different times but filed under different addresses. VCAT does not publicly identify the specific addresses involved in those cases.

The next test for Melbourne's patchwork system will come in the second half of 2026, when the State Government's revised planning portal — replacing the existing Planning Permit Activity Reporting System — is expected to go live. Whether deduplication tools are built into that platform from day one will determine whether the city is learning from Amsterdam or simply digitising the same mess it already has.