Yale face detection Rule for recognition

<font size=3><font color=#00004D>The database method </font></font>for storing face images we use the Yale face database method. The cropped Yale B database used a 4 gray scale face images in raw PGM format of 4 individuals. The image size is 14(width) x 5 (height) centimetres.
All the faces used here are vertical and have frontal view; second, they are under almost the same illuminate condition. They are in a simpler form to avoid the occlusion and pose missing errors. The acquired images are 8-bit (gray scale) captured with a zebronics web camera (with a linear response function) and stored in PGM raw format.
The file names of the images in this database have been named in a special order mentioning the pose and illumination detail. The first part of the filename begins with the base name 'yaleB' and is followed by the two digit number signifying the subject number and then by the two digit number signifying the pose.
The rest of the filename deals with the azimuth and elevation of the single light source direction. An example image yaleB03 P06A+035E+40.pgm belongs to subject 3 seen in pose 6, and the light source direction with respect to the camera axis is at 35 degrees azimuth (A+035) and 40 degrees elevation (E+40).
Here a positive azimuth implies that the light source was to the right of the subject while negative means it was to the left. Positive elevation implies above the horizon, while negative implies below the horizon. The Fig. 3.2 shows the Yale face database used in this project.