A presentation may display one source image at a time, or it may display several source images arranged in a checkerboard pattern, for instance. The RealPlayer window in which your presentation plays back. Source rectangle The portion of a source image you want to display. You might want to display only the top half of a source image in the display window, for example. You can think of the source rectangle as a cropped version of your source image.
Destination rectangle The area of the display window where the source rectangle appears.
Think of the destination rectangle as a separate window within the RealPlayer display window. The source and destination rectangles do not have to be the same size. In the example below, both the source image and destination window are 256 pixels high by 256 pixels wide. The source tags make the top, left quadrant of the source image display in the destination window, effectively magnifying the source rectangle by a factor of 2. Because the destination rectangle defaults to the destination window size, no destination rectangle coordinates are needed.