Perth Lags on Duplicate Image Cleanup as Singapore and Amsterdam Pull Ahead

Perth's local governments are sitting on thousands of duplicate property and streetscape images across public-facing digital systems, and the gap between what the City of Perth and its suburban councils are doing about it — and what comparable cities overseas have already done — is widening.

The issue matters now because Western Australia is mid-way through its Metronet rail expansion, which has triggered a wave of planning applications, rezoning decisions and development approvals across corridors from Ellenbrook to Yanchep. Each of those processes generates georeferenced imagery that feeds into land information databases. When those databases carry duplicated or superseded images, planning officers and the public are working from unreliable visual records.

What Perth Is Actually Doing

The City of Perth and Landgate — the state government's land information authority based in Midland — both maintain image libraries tied to cadastral and planning data. Landgate's systems underpin everything from conveyancing to emergency management, and its Shared Location Information Platform has been progressively updated since its 2019 relaunch to reduce data redundancy. The City of Vincent and the City of Stirling have separately flagged digital asset management as a budget priority in their most recent annual reports, though neither has published a specific duplicate-reduction target or completion date.

The problem is structural. Perth's 30 local government areas each hold their own image caches, often captured by different contractors at different resolutions and on different schedules. When a streetscape in Leederville or a development site in Scarborough gets photographed three times in 18 months by separate entities — a council, a developer, and a state agency — the duplicates rarely get flagged automatically. Manual review is slow and under-resourced.

How Singapore and Amsterdam Handled It

Singapore's Urban Redevelopment Authority completed a systematic deduplication sweep of its GeoSpace data portal in 2023, consolidating imagery across 55 planning zones into a single versioned archive. The city-state mandated that any contractor submitting geospatial imagery to government must include a hash-based duplicate check before upload — a technical standard that effectively prevented new duplicates from entering the system.

Amsterdam went a different route. The City of Amsterdam's Datapunt team, which manages open urban data for the municipality, introduced an automated image comparison pipeline in late 2022 tied directly to its building permit workflow. By mid-2024, the city reported a reduction of more than 40 percent in redundant aerial and street-level images held across its public planning registers. The pipeline flags near-duplicates — not just exact copies — using perceptual hashing, which catches images taken of the same location under different lighting or at slightly different angles.

Perth has no equivalent mandatory standard. Landgate's platform uses metadata tagging but relies on contributing agencies to self-certify that imagery is non-duplicate at the point of submission. That self-certification process has no formal audit mechanism.

The cost comparison is instructive. Amsterdam's Datapunt pipeline reportedly cost the municipality under €200,000 to build and integrate. Storage costs for redundant imagery across Perth's local government sector — while never formally audited — are estimated by data management consultants who work with WA councils to run into the hundreds of thousands of dollars annually when server, licensing and retrieval costs are combined. Those are industry estimates, not official figures.

The WA State Government's Digital Strategy, updated in March 2025, references data quality improvement as a cross-agency priority but does not set enforceable targets for image deduplication specifically. Landgate has a scheduled review of its data submission standards in the fourth quarter of 2026, which could be the practical moment to introduce the kind of hash-check requirement that Singapore mandated three years ago.

For anyone dealing with Perth's planning system right now — whether a homeowner in Mount Lawley checking a development application or a researcher pulling heritage imagery of Fremantle's West End — the practical advice is straightforward: treat any single image in a public planning database as potentially outdated, cross-reference against Nearmap's independently dated aerial archive where available, and lodge a data correction request with the relevant local government if a clear duplicate or superseded image is causing confusion. The system is not broken, but it is behind. The fix exists. Other cities have already used it.