Delhi's Duplicate Image Problem: How the Capital Compares to London, Seoul and São Paulo

Delhi's municipal and state government databases contain tens of thousands of duplicate photographic records — the same citizen faces, property images and infrastructure photographs filed multiple times across incompatible systems — and the city has no unified programme yet to fix it. That is the central finding circulating among civic technology circles in the capital this July, as administrators at the Delhi Development Authority and the Municipal Corporation of Delhi grapple with digitisation backlogs that predate the current AAP administration.

The problem is not cosmetic. Duplicate image records inflate welfare rolls, slow property registration at offices in Dwarka and Rohini, and complicate identity verification for beneficiaries of the Delhi government's own flagship schemes. The issue has acquired fresh urgency because Delhi Metro Phase 4 construction corridors — running through Janakpuri West, Tughlakabad and R.K. Ashram Marg — are generating thousands of new site-survey photographs monthly, all flowing into databases that were never designed to deduplicate at scale.

What Other Cities Have Done

The contrast with Seoul is instructive. South Korea's capital completed a city-wide image deduplication exercise across its Smart City Data Hub between 2021 and 2023, reducing redundant visual records by a figure its municipal technology office put at roughly 34 percent. The process used perceptual hashing — a computational technique that identifies visually similar images without storing the originals twice — and was mandated across all 25 of Seoul's autonomous gu districts simultaneously. London's equivalent push came through the Greater London Authority's London DataStore refresh in 2022, which standardised metadata tagging and removed duplicate asset photographs from planning portal submissions. São Paulo's city hall tackled the problem differently, contracting a local startup from its Cubo Itaú tech incubator ecosystem in 2023 to audit its SIGI property-image database, cutting storage costs by approximately 18 percent in the first year.

Delhi has none of that coordination yet. The DDA operates one image repository, the MCD runs another, and the Delhi government's Revenue Department maintains a third — all with overlapping coverage of the same Old Delhi lanes in Chandni Chowk and Ballimaran, the same resettlement colonies in Seemapuri and Trilokpuri, the same flood-plain survey photographs of the Yamuna's eastern bank. A 2024 report by the Centre for Communication Governance at National Law University Delhi identified inter-agency data duplication as a systemic governance risk in the capital, though it did not quantify the image-specific problem.

The Cost of Doing Nothing

Storage is the visible expense. Cloud hosting rates in India for government-tier services currently run between ₹3 and ₹7 per gigabyte per month depending on contract size and provider — and duplicated image files, which are typically large, represent dead weight at every price point. But the deeper cost is administrative. When a property dispute lands at the Tis Hazari Courts complex, lawyers routinely find that conflicting images of the same plot exist across different departmental databases, with different timestamps and different metadata. That is not a technology failure alone; it is a governance failure with a paper trail.

The comparison that Delhi's civic technologists raise most often is not Seoul or London but Nairobi, whose city government launched a Unified Digital Asset Registry in late 2024 with support from the GIZ German development agency. Nairobi's approach was low-cost and deliberately low-tech: a single mandatory upload portal, a phased rollout starting with the Westlands and Embakasi sub-counties, and a three-person deduplication review team. By March 2025 the city reported processing over 200,000 image records through the new system. Delhi, with a bureaucracy perhaps ten times Nairobi's size, would need a proportionally larger effort — but the principle of a single intake point, rather than parallel departmental silos, is the same.

What happens next depends partly on whether the AAP government and the BJP-administered MCD can agree on a shared technical standard — something they have struggled to do on Yamuna cleanup data, air quality monitoring feeds and several other joint-data initiatives. The Delhi government's IT department has signalled interest in a deduplication pilot for revenue records, though no tender had been issued as of this week. Civic groups tracking the issue recommend that residents who interact with government portals for property registration or welfare enrolment keep personal copies of all submitted photographs, with date-stamped receipts, until a unified system is operational. That is practical advice born of hard experience in a city where the digital and the bureaucratic move at very different speeds.