Duplicate Images Online: What Officials, Experts and Key Figures Are Saying

A quiet but consequential debate is playing out across Melbourne's libraries, cultural institutions and tech sector: when a digital image appears twice — or dozens of times — in a public archive or commercial catalogue, who decides which version stays, which gets pulled, and what accountability exists for that choice? Pressure from the State Library of Victoria, local government digitisation units and private data firms is forcing the question into the open.

The issue has sharpened in 2026 because several large-scale digitisation projects are hitting their delivery milestones simultaneously. The Public Record Office Victoria, based in North Melbourne's Arden Street precinct, has been processing colonial-era photographic collections that were scanned at multiple resolutions by different contractors over the past four years. The result is tens of thousands of near-identical image files sitting in the same repository, consuming storage, confusing researchers and complicating metadata.

Why the Experts Say This Matters Now

Digital preservation specialists argue that duplicate replacement is not a housekeeping exercise — it is an editorial and legal act. When one version of an image is deleted and another is designated the authoritative copy, decisions about resolution, colour calibration, file format and rights clearance are all locked in. Get it wrong, and the record is effectively altered.

The Australian Society of Archivists, which held its most recent national forum in Melbourne in March 2026, has been circulating draft guidance urging institutions to document every replacement decision with a named officer, a timestamp and a stated rationale. The Society's Victorian chapter has been in contact with the Department of Premier and Cabinet's Digital Victoria team about whether state agencies should adopt a uniform standard before the end of the 2025–26 financial year.

At the commercial end of the market, stock-image platforms operating out of offices along Collins Street and in the Docklands technology precinct have a different set of pressures. Licensing revenue depends on each image having a unique, traceable identifier. When a supplier uploads the same photograph under two separate filenames — sometimes with minor cropping differences — it creates disputed royalty claims. Industry body the Australian Digital Alliance has noted the problem is growing as AI-assisted image generation produces near-duplicate outputs at scale.

The City of Melbourne's own digital infrastructure team, which manages the municipality's open-data portal launched in 2019, acknowledged earlier this year that its heritage photograph collection contained a significant number of flagged duplicates following an automated audit. The council engaged the University of Melbourne's School of Computing and Information Systems to run a perceptual hashing analysis — a technique that detects visually similar images even when file names differ. That project is expected to deliver findings to council officers by September 2026.

Calls for a Consistent Framework

What practitioners across these different sectors keep returning to is the absence of a single agreed protocol. The National Archives of Australia issued guidance on digital preservation formats in 2023, but that document does not specifically address duplicate-replacement workflows or the chain-of-custody requirements that should accompany them.

Advocates at the Electronic Frontiers Australia network have raised a separate concern: that automated deduplication tools, if run without human oversight, can quietly remove images that appear identical to an algorithm but carry different contextual significance — a photograph taken seconds apart from two angles, for instance, or two scans of the same print made at different stages of physical deterioration.

The practical stakes are tangible. Storage costs for the State Library's digital repository have been a budget line item flagged in successive annual reports, with high-resolution image files among the largest contributors. Reducing genuine duplication has a measurable financial upside, but only if the process is governed correctly.

For organisations navigating this now, the clearest near-term step is an internal audit using hash-based comparison tools, followed by human review of any flagged pairs before deletion. The Australian Society of Archivists is expected to release its finalised best-practice guide before the end of 2026. Institutions that want input into that document can contact the Victorian chapter directly through its Swanston Street secretariat. In the meantime, the working advice from information professionals is straightforward: document everything, delete nothing without a named decision-maker on the record.