I am currently working on a project where I have to extract the facial expression of a user (only one user at a time from a webcam) like sad or happy.
There are a lot of programs/APIs to do face detection but I did not find any one to do automatic expression recognition.
The best possibility I found so far:
I used OpenCV for face detection earlier, which was working great, so If anyone has some tips on how to do it with OpenCV, that would be great!
Some user on a OpenCV board suggested looking for AAM (active apereance models) and ASM (active shape models), but all I found were papers.
-So i'm Using Active Shape Models with Stasm, which will give me access to 77 different points within the face, so I would still have to manually map them to expressions.
Any programming language is welcome.
After 2.4 release, opencv came with a face recognition API. You may define sad and happy faces as two different faces and use the API to classify them. If you are looking for any tutorials you can check out opencv's tutorial page, too.