rule states that an image can be divided into nine equal parts
by dividing the image two equally-spaced horizontal lines and
two equally-spaced vertical lines.
The idea is that the four points formed by the intersections of
these lines can be used to align dominant features of the scene in the photograph. Proponents
of this technique claim that aligning a photograph with these
points creates more tension, energy and interest in the photo
than simply centering the feature would.