1. UCF Computer Vision REU 2012 Paul Finkel 6/25/12
Weeks 5 & 6 Presentation
UCF Computer Vision REU 2012
Paul Finkel
6/25/12

2. Correlation Coloring Calculated correlation between rows of videos
Sampled matrices
Histogram of optical flow (HOF)
HOF > sampled matrices
Results show:
High correlation in highly dense crowds
Low density crowds have mixture of high and low correlation
“lines” separate oppositely moving groups
Where panic happens

3. Visualizing Density Changes
Calculate entering and exiting matrices
Observe a specific section (e.g. 10x10)
Sum up how many entered
Sum up how many exited
Density change = # entered - # exited
Density change < 0 => density decreased
Density change > 0 => density increased

4. Visualizing Density Changed (cont'd)
Smoothed surf plot helps visualize how density changes between frames
Dρ/Dt = δρ/δt + ρ.v Δ
Lagrangian
Eulerian