b1) Facial Features (Cont.9)
3. The aspect ratio of feature region. 4. The ratio of inter-feature distances. 5. The difference in orientation between features. 6. The number of directional edge pixels in a region.
7. The ratio of strengths in a region to edge strengths of facial features.
8. The mean gray level of a region (normalized to intensity distribution).
9. The variance in the gray level distribution of a region.