1. Appearance Based Behavior Recognition by Event Driven Selective Attention Toshikazu Wada Takashi Matsuyama

2. Introduction Bottom-up analysis: Erroneous and missing feature will confuse sequence analysis and cause fatal errors. Single-object assumption: Multiple object behaviors cannot be classified simultaneously.

3. Introduction (cont.) Sequence analysis: 1. Active states of NFA are not hidden, they can be monitored at any time 2. We can track all possible feature sequences by using NFA Feature extraction: Image features are extracted in specified image regions which varies with active states of NFA.

4. Behavior Recognition Focusing region sequence Sequence analyzer Event Detector

5. Sequence analyzer The sequence analyzer (NFA) is represented by

6. Event Detector Event code of length 2 at state ρ is represented by: The event of an image I with a focusing region f is represented by e(f, I)

7. If e(f(q k ), I i ) = 1,then ρ=q k If e(f(q k+1 ), I i ) = 1,then ρ=q k+1

8. Experiments

9. Focusing region sequences