||Alpha blending vs.
multiblending at the example of palette windows over an image
Left: With traditional alpha blending this
overview palette blurs together with the photo in the background.
Users cannot tell anymore which of the bushes are part of the
palette and which are part of the photograph.
Right: With multiblending (here a design
called "glass palettes") palette and background are clearly
distinguishable. All visible edges belong to the palette; all color
information belongs to the background. This glass palette design
involves desaturating and embossing the palette
and blurring the background.
See the entire application with
alpha and multiblending.
Alpha blending allows the simultaneous display of
overlapping windows—such as palette windows in visual workspaces.
Although alpha blending has been used in some applications, such
as games, it has not been widely adopted. One reason for the limited
acceptance is that in many scenarios, alpha blending compromises the
readability of content. We introduce a new blending mechanism called
multiblending that uses a vector of blending weights, one for each
class of features, rather than a single transparency value.
Multiblending can in most cases be automatically optimized to preserve
the most relevant features of both the palette and the background
window. In our user study, multiblended palettes provided higher
recognizability of both the background and the palette than the
best participating version of alpha blending.