<graphics> To show a smaller area of an image at a higher
magnification ("zoom in") or a larger area at a lower
magnification ("zoom out"), as though using a zoom lense on a
camera.
Unlike in an optical system, zooming in on a computer image
does not necessarily increase the amount of detail displayed
since this is limited by what is actually stored in the image.
Similarly, you cannot zoom out beyond the full size of the
image.
