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

Delhi's public records infrastructure is riddled with duplicate images — the same photograph filed under multiple citizen IDs, the same property photograph appearing in dozens of land registry entries, the same face attached to conflicting voter roll numbers. The Municipal Corporation of Delhi acknowledged the scale of the problem in its 2025-26 annual digitisation review, which flagged duplicate visual records as one of the top three data-quality failures across its property tax and citizen services portals.

The timing matters. Delhi Metro Phase 4 construction has triggered a wave of property re-surveys across corridors from Janakpuri West to RK Ashram Marg, each generating fresh image documentation that feeds into databases already contaminated by earlier duplication. Meanwhile, the Aadhaar-linked voter roll de-duplication drive run by the Election Commission of India through its EPIC (Electoral Photo Identity Card) programme has exposed just how deeply the problem runs: the commission's own data, published in its 2024 electoral roll revision summary, found that image-based duplicate entries ran into the hundreds of thousands nationally, with Delhi among the top five states by volume flagged for remediation.

What Delhi Is Actually Doing About It

The Delhi government's Department of Information Technology launched its Digital Delhi 2.0 initiative in late 2024, which includes a dedicated deduplication engine for citizen-facing image repositories. The programme, administered through the National Informatics Centre's Delhi state unit at CGO Complex in Lodhi Road, uses perceptual hashing — a technique that identifies visually identical or near-identical images regardless of file name or metadata — to flag suspect records before a human reviewer resolves them. As of March 2026, the department reported clearing roughly 1.4 lakh duplicate image entries from the e-District portal alone, according to figures presented at a state assembly committee hearing.

On the ground in places like Chandni Chowk, where property ownership chains are ancient and often paper-originated, digitisation staff at the Sub-Registrar's Office on Esplanade Road describe a more chaotic picture. Old photographs scanned at low resolution, re-scanned again during later drives, and uploaded by different operators have created layered duplication that automated tools struggle to catch. The South Delhi Municipal Corporation's property mapping project, which covers areas from Saket to Hauz Khas, is piloting a georeferenced image tagging system to prevent new duplicates from entering the system — but the pilot only covers about 12,000 properties so far.

How Delhi Compares to London, Seoul and São Paulo

London's Valuation Office Agency completed a national deduplication sweep of its property image database in 2023, spending roughly £4.2 million on the exercise and reducing duplicate records by an estimated 31 percent, according to figures published in the agency's annual report that year. Seoul's government integrated biometric and image deduplication into its Resident Registration System as early as 2019, making visual record duplication a largely solved problem at the citizen-ID level. São Paulo's city administration, grappling with informally documented favela properties, has faced challenges closer to Delhi's — its Secretaria Municipal de Habitação reported in 2024 that image duplication in its housing registry remained above 18 percent, a figure that city officials were still working to reduce.

Delhi sits somewhere between Seoul's orderly resolution and São Paulo's ongoing struggle. The city has the institutional architecture — the NIC unit, the e-District framework, the Election Commission's EPIC programme — but implementation remains uneven across the 11 revenue districts and three municipal bodies that together constitute the capital's administrative patchwork. Budget allocations for data quality specifically, as opposed to broader digitisation, remain small: the 2026-27 Delhi Budget presented in February allocated ₹43 crore to e-governance infrastructure overall, with no dedicated deduplication line item publicly visible in the budget documents.

For residents, the practical consequence is delay. A property transaction in Lajpat Nagar or a ration card update in Trilokpuri can stall for weeks when a duplicate image flags a mismatch that requires manual verification. Citizens can raise deduplication grievances through the Delhi government's Samadhan portal, or visit the nearest e-District facilitation centre — there are 11 across the capital, including at ITO and Dwarka Sector 10 — to submit corrected image documentation directly. The MCD has also indicated it plans to extend the South Delhi georeferencing pilot to North and East Delhi zones before the end of the current financial year.