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

Melbourne City Council confirmed last month that its open-data image repositories — used by planners, journalists and app developers — contained thousands of duplicate and near-identical photographs, some mislabelled by suburb or date, others simply redundant files consuming server space and distorting search results. The council's Digital Infrastructure team flagged the issue in a June 2026 internal audit, which The Daily Melbourne has reviewed, and is now working through a remediation process expected to run until at least December.

The timing matters. Across 2025 and into 2026, municipal governments globally have scrambled to clean up civic image databases as AI-generated content floods public repositories and as urban planners increasingly rely on geotagged photography for housing density modelling, infrastructure assessment and community consultation. A database cluttered with duplicate images of, say, Swanston Street in 2019 can skew automated analysis of pedestrian traffic or building stock — with real consequences for planning decisions.

What Melbourne Is Actually Doing

The council's remediation effort is centred on two programs. The first is a deduplication sweep run through the Spatial Data Infrastructure unit on the fifth floor of 200 Collins Street, using perceptual hashing software to flag visually near-identical images regardless of filename. The second is a community audit program called Melbourne Open Eyes, launched in March 2026 in partnership with RMIT University's Geospatial Science department in Bundoora, which invites registered volunteers to manually review flagged images and confirm or dispute automated deletion recommendations.

Fitzroy and Collingwood have been the first inner-city precincts to have their image sets cleared under the program, according to the council's published project tracker. Outer suburbs including Sunshine and Dandenong are scheduled for the second phase, beginning September 2026. The council has not publicly disclosed the total number of images affected, but the audit document reviewed by this masthead describes the repository as holding more than 1.4 million files, with a preliminary automated scan flagging roughly 18 per cent as potential duplicates.

That 18 per cent figure is not unusual by global standards. Amsterdam's municipal archive, the Stadsarchief, reported in its 2025 annual report that a similar AI-assisted review of its digital collection found a duplication rate of approximately 14 per cent — lower than Melbourne's preliminary figure, though Amsterdam's archive is primarily historical rather than operational. Toronto, which began its own deduplication project under the City's Open Data team in late 2024, has publicly reported clearing more than 200,000 redundant files from its civic photography library by April 2026, a process that took about 18 months.

How Melbourne Compares — and Where It Falls Short

Seoul's approach is the one most urban data specialists point to as the benchmark. The Seoul Metropolitan Government integrated deduplication protocols directly into its image ingestion pipeline in 2023, meaning duplicates are blocked at the point of upload rather than cleaned up retroactively. Melbourne, by contrast, is still working through a legacy backlog before it can implement any upstream fix — a sequencing problem that Toronto also encountered.

Where Melbourne has an edge is in its partnership model. The RMIT collaboration brings postgraduate students into the verification process as part of credited research projects, reducing labour costs and generating peer-reviewed methodology that smaller councils across Victoria can replicate. At least three regional councils — including Greater Bendigo — have expressed interest in adopting the Melbourne Open Eyes framework, according to the program's publicly listed partner enquiries page on the RMIT website.

The practical stakes extend beyond tidy filing. Housing researchers at the University of Melbourne's Melbourne School of Design, based in Parkville, have pointed out that duplicated street-level imagery can artificially inflate the apparent density of photographic coverage in certain postcodes, making some neighbourhoods appear better documented than they are when councils make resource allocation decisions.

The council's Digital Infrastructure team is expected to publish a public progress report in October 2026. Residents and organisations that use the council's open image library — accessible through the Melbourne Data platform — can register feedback on incorrectly flagged images through a form that went live on 1 July. For developers and planners relying on that data in the meantime, the council recommends cross-referencing any downloaded image sets against the project tracker before using them in analysis or public-facing work.