Delhi's Digital Archives Race to Fix Duplicate Image Crisis This Week

Delhi's principal archival and civic bodies spent much of this week in damage-control mode after a systems audit revealed thousands of duplicate image files embedded across multiple government databases, slowing down public-facing portals and creating confusion in official heritage documentation projects. The problem surfaced formally on July 1 when the Delhi Urban Art Commission flagged the bottleneck to its oversight committee, according to internal correspondence reviewed by The Daily Delhi.

The issue has immediate consequences because three major digitisation drives are converging at once. The Archaeological Survey of India's Delhi Circle is in the middle of cataloguing monuments across Mehrauli and Nizamuddin. The Delhi Metro Rail Corporation is simultaneously uploading construction-progress photographs for the Phase 4 corridors—specifically the Janakpuri West to Krishna Park Extension stretch. And the Municipal Corporation of Delhi has been building a geo-tagged property image database to support its revised property-tax assessment programme, which went live in April 2026. Duplicate records across these overlapping systems are generating mismatched files and, in some cases, wrong images being attached to official property records in localities like Karol Bagh and Shahdara.

What Went Wrong and Where

The root of the problem is the absence of a shared image-deduplication protocol across agencies. Each body—DUAC, MCD, DMRC, ASI—runs its own content management system with no automated hash-checking to catch identical or near-identical files uploaded more than once. When multiple departments photograph the same site—say, the Qutub Minar precinct or the Lal Qila ramparts for different regulatory and tourism purposes—the same image can enter three separate archives under different filenames and metadata tags. Estimates circulating among technical staff put the number of flagged duplicate files at more than 40,000 across the combined databases, though an official verified figure has not yet been published by any authority.

The National Informatics Centre, which provides technical backbone for several of these portals, was brought into an emergency working session on July 2 at its Lodhi Road campus. The session focused on deploying perceptual-hashing tools that can identify visually identical images even when file names and upload dates differ. Perceptual hashing—a technique widely used by commercial image platforms—compares pixel-pattern signatures rather than just file metadata, making it far more reliable for catching duplicates that have been re-saved or re-compressed before upload.

Practical Steps and What Comes Next

For Delhi's heritage documentation specifically, the stakes are higher than they might appear. The ASI Delhi Circle manages records for 174 centrally protected monuments within the National Capital Territory. Duplicate or mislabelled photographs in those records can complicate conservation orders, distort condition-monitoring timelines, and create legal ambiguity when encroachment cases go to the National Green Tribunal or civil courts. The Yamuna riverfront, where both heritage and environmental documentation overlap—think the Salimgarh Fort complex and the ongoing cleanup monitoring around Rajghat—is one zone where accurate, unique image records are particularly consequential.

The MCD has given its ward-level teams until July 15 to manually verify property images in three pilot zones: Rohini Zone, Central Zone covering Chandni Chowk, and South Zone covering Greater Kailash. Staff have been advised to cross-reference images using the property unique identification numbers issued under the Unified MCD's 2023 rationalisation exercise. Any file that cannot be matched to a verified UIN is to be quarantined rather than deleted, pending review.

Residents who have recently submitted property documents through the MCD's online portal—accessible via the mcdonline.nic.in platform—can request a verification status update by citing their application reference number. Officials have not announced any deadline extension for tax assessments linked to the affected records, meaning property owners in Karol Bagh and Shahdara in particular should follow up proactively rather than assume a grace period will be granted. The NIC has indicated a full deduplication report should be ready before the end of July, at which point inter-agency protocols may be standardised across the city's civic tech infrastructure for the first time.