18.03.2014 Views

Recognition of facial expressions - Knowledge Based Systems ...

Recognition of facial expressions - Knowledge Based Systems ...

Recognition of facial expressions - Knowledge Based Systems ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

---------------------------------------------------------------<br />

1: P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 Exp AU1 AU2 AU4 AU5 AU6 AU7 AU9 AU10 AU11 AU12 AU15<br />

AU16 AU17 AU18 AU20 AU21 AU22 AU23 AU24 AU25 AU26 AU27<br />

2: 3 4 3 5 1 1 3 2 3 5 Fear 1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 1 0 0<br />

3: 4 5 5 7 4 3 3 5 6 2 Surprise 1 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1<br />

4: 2 4 2 5 3 1 3 2 2 3 Sadness 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0<br />

5: 2 3 2 3 1 1 3 2 2 2 Anger 0 0 1 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0<br />

.............................................................<br />

483: 3 3 3 6 4 2 2 6 6 2 Surprise 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1<br />

484: 3 3 2 2 1 1 2 1 2 6 Happy 0 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0<br />

485: 3 3 2 4 1 1 2 1 2 6 Happy 0 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0<br />

//---------------------------------------------------------------<br />

Listing 8. Final data extracted from the initial database (version II)<br />

For every row, the sequence <strong>of</strong> Action Units was encoded by using the value “1” for<br />

denoting the presence <strong>of</strong> the AU and “0” for absence. The discretization process for the<br />

given example was done on 7 classes per parameter basis. For the conducted<br />

experiments, there were also generated training files with 5 and 8 classes per parameter<br />

discretization.<br />

CPT Computation Application<br />

The application is used for determining the values in the table <strong>of</strong> conditioned<br />

probabilities for each <strong>of</strong> the parameters included in the Bayesian Belief Network.<br />

Initially, a BBN model can be defined by using a graphical-oriented application, as<br />

GeNIe. The result is a “XDSL” file that exists on the disk. The current application has<br />

been developed in C++ language. It parses an already made “XDSL” file containing a<br />

Bayes Belief network and analyses it. It also load the data related to the initial samples<br />

from the Cohn-Kanade database. For each <strong>of</strong> the parameters it runs some tasks as shown:<br />

- determines the parent parameters <strong>of</strong> the current parameter<br />

- analyzes all the states <strong>of</strong> the parent parameters and determines the all possible<br />

combination <strong>of</strong> the states<br />

- for each state <strong>of</strong> the current parameter, passes through each <strong>of</strong> the possible<br />

combinations <strong>of</strong> the parents and:<br />

o create a query that includes the state <strong>of</strong> the current parameter<br />

o add the combination <strong>of</strong> parent parameters<br />

- 76 -

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!