Delhi's Duplicate Image Problem: How the Capital Stacks Up Against Mumbai, London and Seoul

Delhi's municipal and government digital archives contain tens of thousands of duplicate images — photographs of the same potholes filed twice, the same heritage structures catalogued under multiple names, the same beneficiary faces appearing in separate welfare databases — and the agencies responsible for cleaning them up are, by most accounts, well behind where comparable cities were at a similar stage of digitisation.

The problem matters now because Delhi is in the middle of several overlapping data-heavy projects. The Delhi Metro Rail Corporation is processing property and station documentation for Phase 4 expansion across corridors including Janakpuri West to RK Ashram Marg. The Delhi Development Authority's land-record digitisation drive, which began in earnest in 2023, has pulled in photographic evidence from across zones from Dwarka in the south-west to Rohini in the north. When duplicate images sit undetected inside these systems, they inflate cost estimates, slow approvals and, in welfare programmes, can result in double payments or wrongful exclusions.

What Delhi's Own Agencies Are Dealing With

The Municipal Corporation of Delhi, which absorbed three legacy bodies in 2022, inherited three separate photographic archives that were never fully reconciled. Field documentation from North, South and East Delhi bodies was stored in incompatible formats, and a 2024 internal audit — details of which were tabled before the standing committee — identified duplication as a primary reason why property-tax assessment images failed verification checks at a rate that delayed collections in wards across Shahdara and Karol Bagh. The MCD has since piloted an AI-assisted deduplication tool in its central repository at the Civic Centre on Minto Road, but the rollout to all 12 zones had not been completed as of this quarter.

The Delhi government's e-district portal, run under the National Informatics Centre, faces a related challenge. Aadhaar-linked image verification has reduced some duplication in welfare delivery, but the portal still carries a backlog of unlinked records from schemes that pre-date the Aadhaar integration requirement, particularly in Old Delhi localities like Chandni Chowk and Matia Mahal where address documentation is historically inconsistent.

How Other Cities Handled the Same Mess

Mumbai took a more centralised approach. The Brihanmumbai Municipal Corporation contracted a dedicated deduplication layer into its GIS platform by 2023, prioritising the property card system in densely documented zones like Dharavi and Bandra East. By the end of that financial year, the BMC reported reducing redundant image entries in its building-permission database by roughly 34 percent, according to figures published in its annual digital governance report. Delhi has no equivalent published benchmark yet.

London's experience is instructive in a different way. When Transport for London began its Healthy Streets photo-documentation programme across all 33 boroughs in 2021, it discovered that street-condition images from overlapping contractor surveys created a duplication rate above 40 percent in some inner-city zones. TfL resolved the problem by mandating GPS-stamped metadata at capture — a requirement Delhi Metro has now built into its Phase 4 documentation contracts, though legacy data from Phase 3 stations including those on the Pink Line remains unaudited.

Seoul's approach was the most aggressive. The Seoul Digital Foundation, established in 2019, built a city-wide image deduplication engine tied to its smart-city data hub, and the city mandated interoperability across all 25 autonomous districts by January 2024. The result was a measurable drop in processing time for construction permits, with the Seoul Metropolitan Government citing a reduction from an average of 19 days to 11 days for standard approvals after duplicate-image backlogs were cleared.

Delhi's digital governance officials have pointed to the post-merger MCD complexity and the sheer scale — the capital's area covers more than 1,400 square kilometres across 272 wards — as reasons the timeline has stretched. Those are real constraints. But Mumbai is comparably complex, and Seoul started later and finished faster.

For residents and businesses, the practical upshot is straightforward. If you are applying for a building approval, a welfare transfer, or a land-mutation certificate through any Delhi government portal, attach freshly dated, GPS-tagged photographs and retain the original files. Until the deduplication backlog is cleared — a process the MCD has described as a multi-year programme — applications with ambiguous image provenance are more likely to be flagged for manual review, adding weeks to processing times.