how to classify normal faces and smiling faces

how to classify normal faces and smiling faces. What Technique is involved behind this?

[Sean de Wolski]

But what about those of us whose normal face is smiling, i.e. happy people?

[Sivakumaran Chandrasekaran]

Thanks Sean. This is just an academic project.I think that 100 % accuracy is not required here. so, i did not consider that factor.

Answer 1

[Image Analyst]

I think someone asked this earlier this summer. There are several patents covering this. Look them up and they will tell you the whole algorithm. That's what they have to do in order for their patent to be granted.

You can also try by looking around here: http://iris.usc.edu/Vision-Notes/bibliography/contentspeople.html#Face%20Recognition,%20Detection,%20Tracking,%20Gesture%20Recognition,%20Fingerprints,%20Biometrics It has sections like:

21.3.6 Facial Expressions and Emotion Analysis and Description

    21.3.6.1 Face Expression Recognition and Analysis, Facial Expression Analysis, Facial Expressions
        21.3.6.1.1 Three-Dimensional Face Expression Recognition and Analysis
        21.3.6.1.2 Face Action Units for Expressions and Motion Analysis
        21.3.6.1.3 Face Expression Recognition from a Single Image 
    21.3.6.2 Emotion Recognition from Face Images
        21.3.6.2.1 Emotion Recognition, from Other Than Faces 
    21.3.6.3 Facial Expressions, Overviews, Surveys, Data

[Sivakumaran Chandrasekaran]

Thanks Image Analyst. Does the site which you referred has the code. I got some related papers only from it. Moreover, whenever i see the site, I am little bit shocked and getting the feeling that MATLAB has huge concepts and difficult.

[Image Analyst]

That site had just the papers. I thought you were going to program up some algorithm on your own, that is assuming you were just going to implement an existing algorithm rather than invent your own. If you simply want to run someone else's code, then see if there is one in the File Exchange that you can run. Or else hire someone to write some for you, or else see if you can buy some code from someone who is selling such code.