What is Abnormal Behaviour ?
• Abnormal Behaviour is a pattern in the data
that does not conform to the expected normal
• Also referred to as outliers, exceptions,
suspicion, surprise, etc.
• Example: set of data points
Video Surveillance Example
A car on pedestrian roadway
A piece of luggage left in a check in-area
Source: Performance Evaluation of Tracking and Surveillance dataset (PETS)
• Defining a representative normal behaviour is
• The boundary between normal and outlying
behaviour is often not precise.
• The exact notion of an outlier is different for
different video surveillance applications.
• Availability of labelled data for
• Data always contain noise.
• Normal behaviour keeps evolving
Abnormal Behavior Detection
• Optical flow
• Active contour
• Feature based
Unsupervised Behavior Modeling
•The following trajectory
has been generating by:
on the video stream;
•Selecting the first
•Every point on the
trajectory represents a
frame from the video
Visual Resampling Example
Similar segmentsPC: for principal components
Behavior Model Output
• Label : each test instance is given a normal or
• Score: each test instance is assigned an
• Allows the output to be ranked
• Requires an additional threshold parameter
• To test the feasibility of statistical resampling:
– The Ionosphere dataset from UCI machine learning
Repository will be used.
– This dataset are radar signals sent into the ionosphere and
the class value indicates whether or not the signal
returned information “Good” or “Bad” on the structure of
• To test the feasibility of visual resampling: A set of
animated videos with real backgrounds will be
generated for the following events:
– Walk, Run, Jump, Gallop sideways, Bend , One-hand wave,
Two-hands wave, Jump in place, Jumping Jack, Skip.
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