Once the image is scanned, Csubwindow increases the width and
height up to the scale factor s set by the detector in order to detect
various scales of faces in it. This process is repeated until the size
is bigger than that of the image as explained earlier. Other research
works suggest to increase the size of Csubwindow as much as the scale
factor with the image scale maintained same, to increase only the size
of the image as much as the scale factor, and to increase the size of
Csubwindow with the size of the image reducing at the same time.