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

Delhi's municipal and heritage agencies are under renewed pressure to clean up duplicate and misidentified photographs from their public-facing digital archives, a problem that has quietly undermined everything from tourism portals to court evidence submissions. The Delhi Tourism Corporation confirmed earlier this year that its official image library, used by government websites and press offices, contained thousands of duplicate entries — including multiple misattributed photographs of Chandni Chowk and Lal Qila that had been circulating uncorrected for years.

The issue matters now because Delhi is mid-way through a sweeping digital governance push tied to the Phase 4 Delhi Metro expansion corridor and the Smart Cities Mission infrastructure upgrades. Both projects rely on accurate geotagged imagery for planning approvals, public consultations and environmental impact submissions. A duplicated or wrongly labelled photograph does not just waste storage space — it can delay a tender, mislead a planning committee, or misrepresent a heritage site in a UNESCO submission.

What Delhi Is Actually Doing

The Archaeological Survey of India's Delhi Circle, which manages documentation for protected monuments including Humayun's Tomb in Nizamuddin East and Qutb Minar in Mehrauli, has been running a de-duplication audit since January 2026. The audit covers roughly 1.4 lakh digitised photographs held across ASI's internal servers and its publicly accessible archive. Officials at the ASI office on Janpath have not publicly stated how many duplicates have been identified so far, but the audit was scheduled to conclude by the end of June 2026.

Separately, the Delhi Urban Shelter Improvement Board launched a pilot in February 2026 using open-source perceptual hashing tools — software that generates a fingerprint for each image and flags near-identical copies — across its resettlement colony documentation files in areas including Seemapuri and Savda Ghevra. The pilot covered around 80,000 images. The broader rollout, if approved, would extend to all 675 resettlement colonies listed under DUSIB's jurisdiction.

Private-sector pressure is also building. Google Street View, which resumed operations in India after a regulatory gap of more than a decade, has flagged duplicate and outdated panoramas as a recurring quality problem in dense urban grids like Old Delhi's Sitaram Bazaar lane network, where physical changes on the ground outpace re-survey schedules.

London, Seoul and São Paulo Are Further Ahead

By comparison, Transport for London integrated automated duplicate-image detection into its engineering asset management system as early as 2022, reducing redundant entries in its tunnel inspection database by 34 percent within the first operational year, according to TfL's own published efficiency reports. Seoul's Smart City Data Hub, operated under the Seoul Digital Foundation, uses AI-assisted deduplication across municipal CCTV and urban-planning imagery feeds in near real-time — a standard that Delhi's agencies have cited in internal presentations but have not yet matched in practice.

São Paulo's Geosampa platform, maintained by the city's urbanisation company PMSP, publicly documents its image deduplication protocols and publishes annual accuracy rates for its aerial photography catalogue. Delhi has no equivalent public transparency mechanism yet.

The gap is partly a resource question. Delhi's civic IT budgets are distributed across three overlapping bodies — the Municipal Corporation of Delhi, the New Delhi Municipal Council covering Lutyens' Delhi, and the Delhi government's own IT department at ITO — creating coordination problems that peer cities with unified municipal structures do not face in the same way.

For institutions, heritage organisations and government departments working with Delhi's image databases right now, archivists recommend flagging duplicates directly through the ASI Delhi Circle's Janpath office rather than waiting for the audit's conclusions. The DUSIB pilot's project team is also accepting technical feedback through its listed portal. The practical upshot: anyone submitting imagery for planning or legal purposes in Delhi should run their own deduplication check before submission — because the official safety net is still being assembled.