2. what are we
looking at?
Texture: Theory and Data Mapping
Integral and Separable Dimensions: Glyph Design
Representing Quantity
Perceiving Patterns in multi-dimensional Data
6. the gabor function
The gabor function / filter is a
process that is used for edge
detection
We don’t need to understand the
maths, just how it works.
Worth understanding as the
function works in a very similar
way to human perception
7. the gabor function
“A number of electrophysiological and psychophysical experiments show
that V1 and V2 contain large arrays of neurons that filter for orientation
and size information at each point in the visual field. These neurons have
both a preferred orientation and a preferred size (they are said to have
spatial and orientation tuning). They are either weakly color coded or not
color coded, responding to luminance patterns only.”
8. the gabor function
Texture segmentation is the name given to the
process whereby the brain divides the visual
world into regions based on texture.
10. Primary Perceptual Dimensions of
Texture
Orientation O: The orientation of the cosine component
Scale S: The size – 1/(spatial frequency) component
Contrast C: An amplitude or contrast component
20. In order to make a set of nominal coding textures
distinctive, make them differ as much as possible in
terms of dominant spatial frequency and orientation
components.
As a secondary factor, make texture elements vary in
the randomness of their spacing.
33. “Will the color-coding scheme interfere with our
perception of glyph size and therefore distort
perceived population level?”
“What if we use both color and size to represent
a single variable—will this make the information
clearer?”
42. If it is important for people to respond holistically
to a combination of two variables in a set of glyphs,
map the variables to integral glyph properties.
43. If it is important for people to respond analytically
to a combination of variables, making separate
judgments on the basis of one variable or the other,
map the variables to integral glyph properties.
56. When designing a set of glyphs to represent quantity,
mapping to any of the following glyph attributes
will be effective: size, lightness (on a dark
background), darkness (on a light background),
vividness (higher saturation) of color, or vertical
position in the display.
58. Ideally, use glyph length or height, or vertical
position, to represent quantity.
If the range of values is large, consider using glyph
area as an alternative. Never use the volume of a
three-dimensional glyph to represent quantity.
60. Multidimensional Discrete Data: Uniform
Representation versus Multiple Channels
Spatial Position Position in Space (x, y, and z) 3
Colour Defined by colour theory 3
Surface Texture Orientation, Size, and Contrast 3
Motion Coding Movement (more research needed) 2 or 3
Shape Size and Orientation 2+
Blink Coding On / Off 1
61. In general, the use of heterogeneous display
channels is best combined with meaningful mappings
between data attributes and graphical features of a
set of glyphs.
62. Stars and Whiskers
What happens if no natural
mappings exist?
Whisker and Star plots can be
used
79. The sky is the limit
as designers, you should be able to come up with
solutions to visualisation problems
80. RECAp…
Texture: Theory and Data Mapping
Integral and Separable Dimensions: Glyph Design
Representing Quantity
Perceiving Patterns in multi-dimensional Data