texture and glyph design
TRANSCRIPT
digital-media@rgutexture and glyph design
what are we looking at?
Texture: Theory and Data Mapping
Integral and Separable Dimensions: Glyph Design
Representing Quantity
Perceiving Patterns in multi-dimensional Data
Texture: Theory and Data Mapping
WHAT IS TEXTURE?
the gabor function
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
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.”
the gabor functionTexture segmentation is the name given to the process whereby the brain divides the visual world into regions based on texture.
the gabor function
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
Texture Contract Effects
Texture Contract Effects
Texture Contract Effects
Texture Contract Effects
Other Dimensions of Visual Texture
Other Dimensions of Visual Texture
Nominal Texture Codes
Nominal Texture Codes
Nominal Texture Codes
1 2 3 4 5 6
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.
Using Texture for Univariate and Multivariate Map Displays
Use simple texture parameters, such as element size or element density, only when fewer than five ordinal steps must be reliably distinguished.
To display a bivariate scalar field, consider mapping one variable to colour and a second variable to variations in texture.
Quantitative Texture Sequences
TemperaturePressureWind Speed
Integral and Separable Dimensions: Glyph Design
a glyph is a graphical representation of something else
nominal ordinal interval ratio
MikeMarkJohn
Strongly AgreeAgree
Disagree
47
15Kelvin
“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?”
SEPERABLE
Integral
The distinction between integral and separable dimensions
Restricted Classification Tasks
Task is created with layout similar to this
Restricted Classification Tasks
Restricted Classification Tasks
Speeded Classification Tasks
Speeded Classification Tasks
Interference
Interference
Redundant Size
Redundant
Colour & Size
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.
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.
Integral-Separable Dimension Pairs
Experiment TimeYou will be shown a dimension pair and an image. Your
task is to determine how many are in each category
Group Location
Colour
black and red
left and right
easy?lets try a few…
Motion
Colour
Shape Type
Colour
Size
Orientation
x-Size
y-Size
Red-Green
Yellow-Blue
That last one was mean(sorry)
Representing Quantity
Size
BrightnessHeight
Orientation
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.
1D 2D 3D
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.
Representing Absolute Quantities
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
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.
Stars and Whiskers
What happens if no natural mappings exist?
Whisker and Star plots can be used
Perceiving Patterns in multi-dimensional Data
1d and 2D
3D
Size Colour Shape
Size
Colour
Shape
4D and 5D
The Joy of Stats
6D and more!
The sky is the limitas designers, you should be able to come up with
solutions to visualisation problems
RECAp…
Texture: Theory and Data Mapping
Integral and Separable Dimensions: Glyph Design
Representing Quantity
Perceiving Patterns in multi-dimensional Data