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Alternative Views of Overlay Modes

An alternative set of source videos used to provide a different real world view is shown here to help illustrate alpha blending. They use a landscape photo as one and the other is half of a color and half of a black and white gradient photo. First is shown the Aritmetic, Logical, and Graphic-Art views. After that the Porter Duff overlays are shown using the same source videos but with each of the Source videos offset in a different direction so that the generated output is more obvious.

Figure 12.6: Normal and Arithmetic overlays

Figure 12.7: Logical overlays

Figure 12.8: Graphic Art overlays

Figure 12.9: Offset source videos to illustrate Porter Duff overlays

Figure 12.10: Porter Duff overlays