There are two kinds of scale or stretch modes: Scale
To Fill and Scale to Fit.
The Aspect Ratio is the relationship between the width and
height. If the Aspect Ratios of image file and Flash slide are
same, Scale to Fill and Scale to Fit have same effects.
If the Aspect Ratios are different, for Scale To Fill mode,
the image will stretch and fill the area of the slide, the redundant
image on the edge will be cut off. For Scale To Fit, the image
will stretch and fit into the area of the slide, so there will
be "blank area" in the silde.
Scale To Fit: