Figure 3. Alignment of face features.

This figure illustrates the alignment procedure with a face image (note that this procedure is actually used for aligning response maps, cf. previous figure). Four subregions are extracted from each face image as shown, such that the corresponding feature of interest (left eye, right eye, nose, or mouth) is in the image center. Feature coordinates are indicated by crosshairs in the big ( = original) image, and were obtained through manual marking.