Event Detection in Video
Filip Nálepa
Outline
● Motivation
● Application
● Formalization
Motivation
● Automatic surveillance
video analysis
● Real-time alarms for
suspicious behaviour
Staticflickr.com
Event Detection Application
● People related events
● Restricted area entrance
● Waiting
● Meeting
● Real-time detection
● OpenCV library
● Four-step event detection process
Person Detection
Tracked Point Selection
Person Tracking
Event Detection
Person Detection
● Face detector
● No adaptation needed
● Easy detector replacement
Tracked Point Selection
● Well trackable points selected automatically
● Corners – easily indentifiable
● Method by Shi and Tomasi
Person Tracking
● Optical flow method – motion vectors
● Lucas-Kanade algorithm
● A few points tracked
→ fast
Event Detection
● Only one reference point of each person
● Event types
● Time related
● Speed related
● Place related
● Meeting
● Person identification
● Combinations
– concurrence, sequence
Application Screenshot
Formalization
● Event detector – function
● BasicEventDetector: Video → P(Event)
● AdvancedEventDetector: P(Event)k
→ P(Event)
Summary
● Application for human tracking in video
● Real-time event detection
● Event detection formalization
Thank you for your attention.