1. Detecting Motion Pattern in Optical Flow Fields
We can compute the local speed gradient to detect certain basic motion patterns.
The speed gradient is defined as the direction of the steepest speed increase, regardless of the direction of motion.
May 3, 2018
Computer Vision Lecture 23: Motion Analysis

2. Detecting Motion Pattern in Optical Flow Fields
There are four different basic motion patterns: counterclockwise and clockwise rotation, contraction, and expansion. They can be combined to form spiral motion.
counterclockwise
clockwise
contraction
expansion
movement
speed gradient
Idea: A consistent angle between the direction of movement and the orientation of the speed gradient indicates a specific motion pattern.
May 3, 2018
Computer Vision Lecture 23: Motion Analysis

3. Detecting Motion Pattern in Optical Flow Fields
Angles other than 0, 90, 180, and 270 degrees correspond to spiral motion patterns.
direction of movement
orientation of speed gradient
May 3, 2018
Computer Vision Lecture 23: Motion Analysis

4. Computer Vision Lecture 23: Motion Analysis
And this is… The End
May 3, 2018
Computer Vision Lecture 23: Motion Analysis