color for online mapping: still difficult to choose by beate weninger (g2lab, hcu hamburg)
DESCRIPTION
Presented at the ICC 2013 pre-confernece workshop "mapping in a digital world"TRANSCRIPT
[email protected] @beaweb
Color for Online Mapping:
Still Difficult to Choose
ICC 2013 pre-conference workshop "Mapping in a digital world"
Motivation
Official traffic noise map of the city of Hamburg Color scale according DIN 18005-2
Color and Cartography // Color Advice
Colors of a scale should according to Levkowitz (1996): 1. „Preserve the order of the original values“; 2. “convey uniformity among values they are
representing, and representative distances between them; and
3. create no artificial boundaries that do not exist in the original data.”
Color and Cartography // Guidelines
Color and Cartography // Color Perception
Physical reactions, e.g.
Simultaneous contrast (1) Perception of object size Effect of object size Depth effect (2)
Lübbe 2013
(2)
(1)
Color and Cartography // Color Perception
Psychological reactions, e.g.
Color perception is influenced by the object (shape) Emotional reactions Trust issues
Color and Cartography // Color Perception
Color vision deficiencies
Official color scale according DIN 18005-2 transformed
Color Design Aspects for Webmapping
1. Harmonical hierarchy
Only systematic variation of lightness and saturation Consider spatial distribution for balanced scales (order,
complexity, object size) 2. Nature of the Scale: logarithmic etc. 3. Consistency 4. Qualitative meaning 5. Consider CVDs and situational CVDs
Design Challenges
Variety of screen sizes and use cases
Practitioners‘ wish list Many classes Flexible scale Traffic light system
New Scale // Qualitative Aspects
Different hues in a harmonical order with few lightness steps per hue supports recognition!
Card sorting task showed: users would order greens differently!
New Scale // CVD
Normal Vision deuteranopia (green-blindness) protanopia (red-blindness)
Conclusion // Focusing on Neocartography
How can we abandon rainbow and traffic light schemes? (Why are they still available in software?)
Do screen sizes and use cases effect color perception?
Clear rules are needed that support map-makers from a
non-traditional background ColorBrewer 2.0 extension?
Let`s bring the topic back on the to-do list!
Conclusion // Focusing on Neocartography
How can we abandon rainbow and traffic light schemes? (Why are they still available in software?)
Do screen sizes and use cases effect color perception?
Clear rules are needed that support map-makers from a
non-traditional background ColorBrewer 2.0 extension?
Let`s bring the topic back on the to-do list!
# What’s the map-maker’s aim? (raise awareness, bring forward an argument, aesthetic map…) # What’s most important: discriminability of colors, trust in the map, visualize distribution of values… # Is there a critical value in the scale that should be highlighted? # ….
More on Color
ICC Papers on color: Weninger: The Effects of Colour on the Interpretation of Traffic Noise in
Strategic Noise Maps
Kröger, Schiewe, Weninger: Analysis and Improvement of the OpenStreetMap Street Color Scheme for Users with Color Vision Deficiencies
[email protected] @beaweb
References
Levkowitz, H. (1996). Perceptual Steps along Color Scales. International
Journal of Imaging Systems and Technology 7, 97–101.
Lübbe, E. (2012). Farbempfindung, Farbbeschreibung und Farbmessung: Eine Formel für die Farbsättigung. Springer: Berlin, Heidelberg, New York.