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CROWDLENS

AI-Powered Crowd Intelligence & Public Safety Platform. A 64-hour hackathon sprint for final-year engineering students in 2-member teams.

Level 2 · 64 Hours · 200 Marks
SUBMISSIONS CLOSED

The hackathon submission deadline has passed

September 4, 2026 at 10:00 PM IST (Asia/Kolkata)

CROWDLENS Autonomous Crowd Intelligence Center
● CCTV Vision OnlineSRI Index Model v2.4

REAL-TIME COMMAND SYSTEM

Sub-2-Second Stampede & Structural Overload Prediction

Challenge Level

2

Duration

64 Hours

Team Size

2 Members

Total Marks

200

Section 01

Executive Summary

CROWDLENS is a real-time, privacy-first AI platform designed to predict and prevent crowd-related disasters by transforming passive CCTV networks into proactive public safety guardians.

Leveraging computer vision, edge AI and predictive analytics, the system detects early warning signs of dangerous crowd behavior and structural overloads before they escalate into tragedies. Build a production-ready prototype that ingests live or recorded video, analyzes crowd dynamics in real time, predicts safety threats with under 2-second latency, and maintains absolute privacy — no facial recognition, no individual tracking.

Core innovation: turn every camera into a predictive safety sensor — without ever identifying a single person.

Section 02

The Invisible Crisis in India's Crowds

India sees over 2,500 crowd-related incidents annually — 1,000+ deaths in five years, 10,000+ injuries, and ₹5,000+ crores in economic loss. Despite 30M+ CCTVs, 99% of monitoring is reactive: guards watch hundreds of screens, structural risks are never monitored live, and no Indian city uses AI for crowd safety at scale.

IncidentYearLocationCasualtiesRoot CauseAI Prevention
Maha Kumbh Mela Stampede2019Prayagraj, UP40+ deadCrowd surge at bridge bottleneckDensity + Flow Analysis
Elphinstone Road Stampede2022Mumbai, MH22 deadPost-event rush, poor barricadingReverse Flow Detection
Rajasthan Temple Tragedy2023Rajsamand, RJ35+ deadNarrow exit, unmanaged queueBottleneck Flow Rate
Morbi Bridge Collapse2022Morbi, GJ135+ deadStructural overloadMass Load Estimate
Chennai Stadium Crush2021Chennai, TN12 deadSudden surge after matchStampede Risk Index

Current systems answer “What just happened?”. CROWDLENS must answer “What is about to happen — and where?”

Section 03

Problem Drivers

Urbanization & Mass Events

600M+ urban population by 2030; religious gatherings draw 50M+ pilgrims annually; transport hubs handle millions daily with zero crowd intelligence.

Aging Infrastructure

70% of bridges are 50+ years old; venues designed for 1980s crowd sizes; no real-time structural load monitoring.

Surveillance Without Intelligence

Passive forensic-only cameras; 20-minute attention span means ~40% of critical events are missed.

Economic & Legal Pressure

Organizers cut crowd-management costs; insurance spikes after incidents; no proactive mitigation tooling exists.

Global Lessons Ignored

Seoul 2022 (158 dead) triggered nationwide AI monitoring; UK stadiums cut incidents 60%; Singapore predicts surges at 92% accuracy.

The Opportunity

India does not need to reinvent the wheel — it needs to deploy it at scale before the next tragedy.

Section 04

Objectives & Success Metrics

Primary objective: a prototype that ingests feeds, analyzes crowd dynamics with CV and predictive models, predicts surges and structural overloads before they occur, and pushes actionable location-specific alerts in under 2 seconds.

Success MetricTargetWhy It Matters
Stampede Prediction Precision≥ 80%Fewer false alarms = trust from security teams
Alert Latency< 2 secondsFaster than human reaction time
Privacy Compliance100%No facial recognition, no individual tracking
Structural Load Accuracy±15% of ground truthPrevents bridge/staircase collapses
Crowd Density mAP≥ 0.78Accurate counting in dense scenes
Stretch GoalDescription
Multi-Camera FusionCorrelate angles for 3D crowd modeling
Edge DeploymentRaspberry Pi + Coral TPU, offline capable
Mobile Responder AppGPS-tagged alerts to security phones
Historical ReplayScrubbable post-incident timelines
Audio FusionMicrophone-based aggression detection
Real-Life DemoActual crowd footage with measurable accuracy (100 bonus marks)

Section 05

Crowd Taxonomy & Event Context

Event TypeVisual SignaturesRisk Profile
Temple FestivalTraditional attire, diyas, narrow corridorsHigh stampede risk in bottlenecks; rear crowds unaware of front compression
Sports StadiumUniform colors, seated sections, wave patternsCrush risk at exits; post-match surge compression
Concert / EDMStage-facing, raised hands, phone lightsTrampling; mosh pit density spikes; heat exhaustion clusters
Protest / RallyFlags, banners, police lines, chantingRapid escalation to volatile; kettling; dispersal patterns
ProcessionLinear movement, slow pace, intermittent stopsCompression at halts; stop-wave propagation
Public GatheringMixed orientation, static clustersGeneral density management; vulnerable demographics
Dynamics StateDefinitionVisual Biomarkers
PassiveStatic/slow-moving; low energyStanding still, seated, minimal arm movement
ActivePurposeful movement; normal energyWalking, queueing, cheering, clapping
AggressiveHostile body language; confrontationChest-forward posture, pointing, pushing
VolatileUnstable; rapid state-switch potentialSudden direction changes, raised voices
PanicFlight response; disordered evacuationRunning against flow, falling, dropped items
DispersingControlled/uncontrolled exitRadial outward flow, emptying central zones

Section 06

Analytics Engine: Detection & Prediction

Demographic profiling is aggregate-only: age and group mix derived from silhouette gait and body proportions, reported as histograms per 5m × 5m grid cell. Never per-person records.

#FeatureSourcePhysics Meaning
F1density_ppm2Detection gridPeople/m² (>6 = danger)
F2velocity_meanOptical flowAverage movement speed
F3velocity_varianceOptical flowSpeed inconsistency = turbulence
F4direction_entropyHeading vectorsLow = laminar, high = chaotic
F5compressibility_indexDensity gradientRate of density increase
F6pressure_proxySocial force modelF = density × velocity² (crush risk)
F7bottleneck_flow_rateGate/exit ROIPeople/minute through chokepoints
F8queue_disorderLine detectionDeviation from straight queue
F9fallen_person_flagPose estimationHorizontal body in crowd
F10arm_raised_ratioPose keypointsCheering vs. distress
F11jumping_frequencyVertical motion FFTRhythmic vs. irregular
F12interpersonal_distanceDetection spacingCollapsing distance = compression
F13reverse_flow_ratioDirection analysis% against dominant flow
F14edge_pressureBarrier proximityStacking against fences/walls
F15age_vulnerability_indexAggregate demographicsChildren + elderly in dense zones
F16stop_wave_propagationTemporal analysisFront-stop signal traveling backward
F17audio_aggression_proxySpectral analysisLow-frequency energy surge
F18structural_load_kNDensity × avg weightForce on deck/stair tread
F19vibration_resonanceVideo motion mag.Oscillation under rhythmic crowd
F20time_to_criticalPredictive modelMinutes until stampede threshold

Stampede Risk Index (SRI)

SRI = 0.30 × f(density_ppm2)
    + 0.20 × f(pressure_proxy)
    + 0.15 × f(velocity_variance)
    + 0.15 × f(compressibility_index)
    + 0.10 × f(reverse_flow_ratio)
    + 0.05 × f(fallen_person_flag)
    + 0.05 × f(age_vulnerability_index)

Prediction horizon: time-series forecast on the last 90 seconds of features. Output format: “Stampede risk critical in 4 minutes at Zone-B”.

0–30GREENNormal monitoring
31–55YELLOWIncreased vigilance; alert ground staff
56–75ORANGEReposition barricades; PA announcement
76–90REDActive crowd management; halt entry
91–100BLACKImmediate evacuation; notify disaster response
Structural SignalDetection MethodThreshold
Mass Load EstimateHeadcount × 70kg avgvs. rated capacity (e.g. 5kN/m²)
Dynamic Load FactorRhythmic jumping/marching frequencyResonance if crowd freq ≈ natural freq
Visual DeformationMotion magnification of handrail/deck> 2mm displacement
Flow-Induced VibrationCamera shake frequency analysisAnomalous oscillation patterns
IF mass_load > 0.80 × rated_capacity AND dynamic_factor > 1.5:
    TRIGGER "Structural Overload Warning"

IF visual_deformation > 2mm OR resonance_detected:
    TRIGGER "Immediate Evacuation of Structure"

Section 07

Technical Requirements

CV ComponentRecommended Models / Methods
People DetectionYOLOv8 / RT-DETR / YOLO-NAS
Multi-Object TrackingByteTrack / OC-SORT (ephemeral IDs)
Pose EstimationMoveNet / YOLOv8-pose
Optical FlowFarneback / RAFT
Motion MagnificationEulerian video magnification
Backend ComponentTechnologyPurpose
Stream ProcessingKafka / Redis StreamsMulti-camera feed ingestion
Time-Series DBInfluxDB / TimescaleDBPer-second feature storage
Prediction APIFastAPISRI & structural alerts (<500ms)
Geospatial GridPostGIS / custom grid enginePixel-to-real-world mapping
Alert BusWebSocket / SSEPush alerts to dashboards & mobile

Dashboard must-haves

  • — Multi-camera mosaic with color-coded zone overlays
  • — Toggleable heatmaps: density, turbulence, stampede risk
  • — Auto-classified event archetype badge with confidence
  • — Dynamic crowd state panel (Passive → Panic)
  • — Predictive SRI timeline with forecast line
  • — Structural load gauge with resonance indicator
  • — Auto-generated incident log

Privacy & ethics architecture

  • — No facial recognition — gait/silhouette only
  • — Ephemeral IDs, no persistence beyond frame sequence
  • — Aggregate histograms per zone, no individual records
  • — Audit trail of every alert with feature snapshot
  • — Consent zones with visible anonymous-AI signage

Section 08

Evaluation & Scoring — 200 Marks

#MetricTargetMarks
M1Crowd Detection mAP≥ 0.7815
M2Event Type Classification Accuracy≥ 0.8510
M3Dynamics State F1 (6-class)≥ 0.7515
M4Stampede Prediction Precision≥ 0.8020
M5Fallen Person Detection Recall≥ 0.9010
M6Structural Load Correlation±15% ground truth10
M7Alert Latency< 2 sec10
M8Presentation & Ethics—10
Bonus CategoryCriteriaMax Marks
InnovationNovel algorithms, unique features, creative problem-solving40
New FeaturesAudio fusion, mobile app, edge deployment30
Real-Life DemoActual crowd footage with measurable accuracy30

Penalty — 48–72 hrs late: −10 marks · 72–96 hrs late: −20 marks

Section 09

Deliverables

IDItemDetails
D1CV/ML Pipeline (/ml)Detection, tracking, optical flow, pose estimation, SRI model, structural analysis.
D2Backend & Streaming (/backend)Ingestion API, time-series DB, WebSocket alert bus, <500ms prediction endpoints.
D3Dashboard (/dashboard)Multi-camera view, heatmaps, predictive timeline, structural gauges.
D4Dataset (/data)10+ annotated clips (UCF Crowd, WWW Crowd, FDST or synthetic).
D5Model CardPer-event performance, confusion matrices, failure modes.
D6Demo Video (2 min)Upload clip → classify → heatmap → SRI climbs → alert → structural gauge.
D7Slide Deck (10 slides)8-min presentation + 4-min Q&A.
D8Innovation DocumentationNew features, algorithms, real-life testing evidence.

Section 10

48-Hour Sprint Timeline

HoursPhaseTasksMilestone
0–2Setup & First LightRepo init, CV pipeline scaffold, test video curationFirst frame processed with detection boxes
2–8Core Detection StackDetection + tracking on dense scenes, optical flow, density gridDensity heatmap rendering live
8–18Intelligence LayerEvent classifier, dynamics states, SRI scoring, fallen-person detectionAlert triggers on test video
18–24Dashboard IntegrationDashboard live, WebSocket alerts, multi-camera mosaicReal-time overlay on dashboard
24–36Structural & AdvancedLoad module, motion magnification, time-series forecastingStructural gauge functional
36–44Polish & Privacy AuditPrivacy audit, latency optimization, edge-case testingEthics architecture verified
44–48Final AssemblyDemo video, deck, README, real-life demo testingRepo locked & submitted

Pro tip for 2-member teams — Member 1: CV pipeline + backend (hours 0–24). Member 2: dashboard + integration (hours 12–48). Overlap 12–24 on API contracts and data flow.

Section 11

Judging Criteria

CriteriaWeightWhat Wins
Safety Prediction25%High stampede precision, plausible structural load, low false alarms, countdown-to-critical
Privacy-by-Design20%Aggregate-only analytics, zero facial recognition, ephemeral IDs, transparent signage
Crowd Science Depth20%Social force modeling, pressure physics, turbulence metrics, age-vulnerability weighting
System Integration15%Video → detection → scoring → alert → dashboard, <2s latency, multi-camera
Presentation10%Public safety narrative, deployment path, confident Q&A
Technical Robustness10%Clean code, optimized models, scalable architecture

Section 12

Constraints & Disclaimers

  • Decision support only. Trained personnel must validate all alerts. CrowdLens augments human judgment; it does not replace it.
  • Privacy is non-negotiable. If the database is breached, no individual may be identified or profiled. Aggregate histograms only.
  • Synthetic data limitations. Models trained on synthetic scenes may not generalize to real festival densities, lighting or cultural clothing. Field validation is required.
  • Bias awareness. Gait-based age estimation and clothing-based classification carry demographic bias risk. Document accuracy variance across attire and body types in your model card.
  • Liability. CrowdLens provides probabilistic risk assessment only. Event organizers remain responsible for physical safety measures, capacity enforcement and emergency protocols.