In order to get more images, you can use GENKI-4k Face, Expression, and Pose Dataset [1]
The GENKI-4K dataset contains 4,000 face images spanning a wide range of subjects, facial appearance, illumination, geographical locations, imaging conditions, and camera models. All images are labeled for both Smile content (1=smile, 0=non-smile) and Head Pose (yaw, pitch, and roll parameters, in radians).
I have used this database to train a smile classifier using LBP + SVM approach (some years ago) and results were quite satisfactory. Steps:
- (1) Face detection
- (2) Get Local Binary Pattern from the face
- (3) SVM classification
Step (2) can be decomposed in:
- crop face region
- normalize face region based on eye coordinates
- histogram equalization or something similar
- Apply LBP to a NxM non-overlapping region
The public GENKI-4K dataset is available for download here [2].
[1] http://mplab.ucsd.edu/wordpress/?page...
[2] http://mplab.ucsd.edu/wordpress/wp-co...
Two sample images:
have you seen opencv's smile-cascade detector ?
what is your plan ?
att_faces might not be the best database for this, you'd have to annotate/label your data manually, and it's probably too small (on its own)