Fusion of Visual Channels - Scientific Visualization: Uncertainty, Multifield, Biomedical, and Scalable Visualization - page 115

•

Connectivity

•

Partition/completeness

• Intersection/overlap

• Depth ordering/partial or full occlusion

• Hierarchy/level

• Density/distribution

• Convexity

• Continuity

• Homeomorphism/genera

• Similarity

• Translation/scaling/rotation/deformation

Semantic Channels provide means to differentiate visual entities by making use of
pre-defined visual languages that encode different semantic concepts.

• Number

• Tex t

• Symbol/ideogram

• Sign/icon/logo/glyph/pictogram

• Isotype

12.3 Constructive Operations on Visual Channels

Let F 1 , F 2 ,..., F n be a set of fields to be visualized in an amalgamated manner. Let

V ( be a set of corresponding visual mappings. The compo-

sition of these visual mappings is thus a function that combines these visual mappings
into a single visual representation, such that,

F 1 ), V ( F 2 ),...,V ( F n )

Λ : V 1 ( F 1 ), V 2 ( F 2 ), . . . , V n ( F n ) → V

where V is a visual representation that is directly displayable on a 2D or 3D display,
and n are different visual mappings, each of which may utilize one

or several visual channels.
The function

V i , i = 1 , 2 ,...,

is usually designed to serve specific requirements of visualization
tasks, which may be one or several of the followings:

Λ

• Association and Correlation —This is the most basic task in multifield visualiza-

tion, with a goal for users to establish correspondence between features in other
field and those in the other fields. The emphasis is placed on the ability to see the
visual mappings of individual fields,

V i , i = 1 , 2 ,..., n , through the composite

visualization V .

• Comparison or Contrast —The goal of the tasks in this category is for users to

examine the similarity or difference between different fields, and to estimate the
changes qualitatively or quantitatively. While the requirement for the ability to