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

The CINELERRA-GG Community, 2021
https://www.cinelerra-gg.org