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

Delhi's municipal authorities are sitting on a problem that has quietly ballooned over the past three years: tens of thousands of duplicate, mislabelled and outdated images embedded in official government portals, heritage documentation systems and the Delhi Metro Rail Corporation's public-facing digital infrastructure. The Delhi Urban Art Commission flagged the scale of the backlog in an internal review completed in March 2026, identifying redundant image records across at least four separate civic databases maintained by the Municipal Corporation of Delhi.

The timing matters. Delhi is mid-way through a major push to digitise heritage records for Old Delhi neighbourhoods — Shahjahanabad, Chandni Chowk, and the Walled City precinct — ahead of a 2027 UNESCO monitoring deadline tied to the city's broader heritage conservation commitments. Duplicate photographs clog these archives, slow verification workflows and, in several documented cases, have caused the wrong building to be flagged for conservation status. One Ballimaran street property was twice misidentified in municipal records because two versions of the same image carried different metadata tags.

What Other Cities Have Done

The comparison with peer cities is instructive, if uncomfortable. Seoul's Smart City Division completed a systematic deduplication sweep of its urban documentation database in late 2024, processing roughly 2.3 million image records using perceptual hash algorithms and reducing redundancy by an estimated 40 percent, according to the Seoul Metropolitan Government's annual digital infrastructure report published in January 2025. London's Historic England ran a similar exercise for its National Heritage List image assets beginning in 2023, with the organisation publicly stating that deduplication was a prerequisite before any AI-assisted condition assessment could be deployed at scale.

São Paulo took a different route. The city's Secretaria Municipal de Urbanismo e Licenciamento partnered with the University of São Paulo's computer vision laboratory in 2024 to build an open-source tool specifically designed for municipal image deduplication in low-bandwidth environments. The tool, released under a public licence, has since been adopted by three other Brazilian state capitals. Delhi's National Informatics Centre, which manages the backend of multiple civic portals, has not yet announced any comparable partnership, though officials at the Centre's Delhi state unit have, according to publicly available meeting minutes from April 2026, placed image data quality on the agenda for the next technical working group convening.

Delhi's Patchwork Response

On the ground, the situation varies sharply by agency. The Delhi Metro Rail Corporation updated its passenger-facing image library for Phase 4 corridor stations — including the Janakpuri West to RK Ashram stretch — in February 2026, removing several hundred duplicate station photographs that had circulated across press kits since the Phase 3 launch in 2019. That exercise was handled internally and took approximately six weeks, according to a project update posted on the DMRC's official website.

The Archaeological Survey of India's Delhi Circle office, which manages documentation for monuments including Humayun's Tomb, Qutub Minar and the Red Fort, maintains a separate image repository that has not undergone any publicly announced deduplication review. Researchers working in the ASI's reference library on Janpath have noted, in submissions to a 2025 heritage stakeholder consultation published by INTACH, that navigating duplicate records adds significant time to any archival query.

The MCD's own digitisation cell, operating out of the Civic Centre on Minto Road, has allocated a budget line for database maintenance in its 2026-27 annual plan, though the specific figure earmarked for image quality work has not been published in documents available as of this writing.

For Delhiites who interact with these systems — property owners filing heritage exemption requests, architects submitting conservation proposals, journalists pulling archive photographs — the practical advice for now is straightforward: always cross-reference images from official portals against the original source documentation, and flag discrepancies directly to the relevant agency's grievance portal. The MCD's online grievance system, accessible at mcdonline.nic.in, accepts technical complaints about database errors. Given the trajectory of cities like Seoul and London, Delhi's deduplication reckoning is not a question of whether it happens — it is a question of how much longer the backlog grows before a structured programme forces the issue.