Abstract
In this paper, we first present a procedure derived from related vision and perception literature to calculate the colour metric ΔE00, as our previous empirical research let us believe that this is a reliable metric that can be useful in cartographic design decisions (Brychtová and Çöltekin, 2015; 2016). In earlier work, we demonstrated that increasing ΔE00 values consistently improves the human judgement of whether two colours are the same or different both with sequential and qualitative schemes. Furthermore, we observed that colour distance ΔE00 = 10 ‘works’ in terms of same/different judgements for two colours, even if the compared colours are (spatially) far apart. Using this knowledge from previous work of others as well as our previous own work, we evaluate a subset of colours used in the well-known online colour recommender ColorBrewer 2.0 against ΔE00 = 10 threshold as a minimum perceptually safe colour distance. The results of the evaluation showed that overall, majority of the evaluated colours are equal to or larger than the perceptually safe ΔE00 = 10, however, there are also colour distances that are considerably lower. These findings suggest that some widely adopted colour schemes might not be ideal under some circumstances, and call for more research.
Zusammenfassung
In diesem Beitrag wird eine Vorgehensweise zur Berechnung der Farbmetrik ΔE00 vorgestellt, die aus benachbarter Fachliteratur der Blick- und Wahrnehmungsforschung abgeleitet ist. Bereits vorausgehende empirische Studien deuten darauf hin, doss hinter dieser Metrik ein zuverlässiges Verfahren steht, das kartographische Gestaltungsüberlegungen unterstützen kann (Brychtová und Çöltekin 2015; 2016). In diesen vorausgehenden Studien wurde gezeigt, doss die Erhöhung von ΔE00-Werten das Unterscheiden von zwei Farben in sequenziellen und qualitativen Farbschemen verbessert. Dabei wurde ouch beobachtet, doss Farbdistanz (ΔE00 = 10) hinsichtlich gleicher und unterschiedlicher Bewertung zweier Farben funktioniert, ouch wenn die verglichenen Farben (räumlich) weit auseinander liegen. Aufder Grund loge dieser Erkenntnisse wird in dieser Studie eine Auswahl an Farben untersucht, die den we it verbreiteten Farbempfehlungen des Online-Tools ColorBrewer 2.0 entnommen sind. Diese Untersuchung berücksichtigt den Schwellwert ΔE00 = 10 als minimal sicher wahrnehmbare Farbdistanz. Die Resultate zeigen, doss die meisten untersuchten Farben dem Farbdistanzschwellwert entsprechen oder über ihm liegen. Es gibtjedoch ouch Farbdistanzen, die beachtlich unter dem Schwellwert liegen. Daraus ist abzuleiten, doss manche weit verbreiteten Farbschemen zu optimieren sind, was weitere empirische Studien erfordert.
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Literature
Asano, Y., Fairchild, M. D., Blondé, L., and Morvan, P. (2016): Color Matching Experiment for Highlighting Interobserver Variability. In: Color Research & Application, 41 (5), pp. 530–539
Bertin, J. (1983): Semiology of Graphics: Diagrams, Networks, Maps. Madison
Borland, D., and Taylor, M. R. (2007): Rainbow Colour Map (Still) Considered Harmful. In: IEEE Computer Graphics and Applications, 27 (2), pp. 14–17
Brewer, C. A. (1989a): Colour Chart Use in Map Design. In: Cartographic Perspectives, (4), pp. 3–10
Brewer, C. A. (1989b): The development of process-printed Munsell charts for selecting map colours. In: The American Cartographer, 16 (4), pp. 269–278
Brewer, C. A. (1994): Colour Use Guidelines for Mapping and Visualization. In: MacEachren, A. M. (ed.), Visualization in Modem Cartography, Tarrytown, NY, pp. 123–147
Brewer, C. A. (1996): Guidelines for Selecting Colours for Diverging Schemes on Maps. In: The Cartographic Journal, 33 (2), pp. 79–86
Brewer, C. A. (1997): Spectral Schemes: Controversial Colour Use on Maps. In: Cartography and Geographic Information Science, 24 (4), pp. 203–220
Brewer, C. A. (1999): Brewer-Colour Use Guidelines for Data Representation. In: Annual Meeting of the American Statistical Association, Proceedings of the Section on Statistical Graphic, Maryland, Baltimore, pp. 55–60
Brewer, C. A.; Hatchard, G. W., and Harrower, M.A. (2003): ColorBrewer in Print: A Catalog of Colour Schemes for Maps. In: Cartography and Geographic Information Science, 30 (1), pp. 5–32
Brewer, C. and Harrower, M. (2012): ColorBrewer 2.0. Retrieved from http://colourbrewer2.org/
Brychtová, A. (2015): Exploring the Influence of Colour Distance and Legend Position on Choropleth Maps Readability. In Brus, J., Vondráková, A., and Voženílek, V. (eds.), Modem Trends in Cartography: Selected Papers of CARTOCON 2014, Heidelberg, pp. 315–326
Brychtová, A., and Doležalová, J. (2015): Designing Usable Sequential Colour Schemes for Geovisualizations. In Gartner, G., and Hu ang, H. (eds.), Proceedings of the 1st ICA European Symposium on Cartography, pp. 31–32.
Brychtová, A., and Çöoltekin, A. (2015): Discriminating Classes of Sequential and Qualitative Colour Schemes. In: International Journal of Cartography, 1 (1), pp. 62–78
Brychtová, A., and Çöoltekin, A. (2016): An Empirical User Study for Measuring the Influence of Colour Distance and Font Size in Map Reading Using Eye Tracking. In: The Cartographic Journal, 1–11
Brychtová, A., and Çöoltekin, A. (2016): The Effect of Spatial Distance on the Discriminability of Colours in Maps. In: Cartography and Geographic Information Science, 1–17
Brychtová, A., and Vondráková, A. (2014): Green vs. Red: Eye-tracking evaluation of sequential colour schemes. In SGEM 2014 Informatics, Geoinformatics and Remote Sensing Proceedings Volume III. Sofia, p. 8
Carter, R., and Huertas, R. (2009): Ultra-large Colour Difference and Small Subtense. Colour Research and Application, 35 (1), pp. 4–17
CIE. (2012): Termlist of international Commission on Illumination. Retrieved from http://eilv.cie.co.at/
Çöoltekin, A., Brychtová, A., Griffin, A. L., Robinson, A. C., Imhof, M., and Pettit, C. (2016): Perceptual Complexity of Soil-landscape Maps: a User Evaluation of Color Organization in Legend Designs Using Eye Tracking. In: International Journal of Digital Earth, pp. 1–22
Derefeldt, G.; Swartling, T.; Berggrund, U., and Bodrogi, P. (2004): Cognitive Colour. Colour Research and Application, 29 (1), pp. 7–19
Fairchild, M. D. (2005): Colour Appearance Models. 2nd ed., Chichester
Foster, D. H. (2011): Colour Constancy. In: Vision Research, 51 (7), pp. 674–700
Gegenfurtner, K. R., and Sharpe, L. T. (2001): Colour Vision: From Genes to Perception. Cambridge. Retrieved from http://books.google.com/books?id=4zQMQLLVkFYCandpgis=I
Gegenfurtner, K. R., Bloj, M., and Toscani, M. (2015): The Many Colours of “the dress.” In: Current Biology, 25 (13), pp. pR543–R544
Google Ngram Viewer (2017): Retrieved from https://books.google.com/ngrams/graph?content=colour+perceptionandyear_start=1800andyear_end=2000andcorpus=15andsmoothing=3andshare=anddirect_url=t1%3B%2Ccolour%20perceptionOfo3BOfo2CcO
Jenny, B., and Kelso, N. V. (2007): Colour Design for the Colour Vision Impaired. In: Cartographic Perspectives, (58), 61–67
Kuehni, R. G. (2001): Colour Space and Its Divisions: Colour Order from Antiquity to the Present. In: Colour Research and Application, 26 (3), pp. 209–222
Lafer-Sousa, R.; Hermann, K. L., and Conway, B. R. (2015): Striking Individual Differences in Colour Perception Uncovered by ‘The Dress’ Photograph. In: Current Biology, 25 (13), pp. R545–R546
Landa, E. R., and Fairchild, M. D. (2005): Charting Colour from the Eye of the Beholder. In: American Scientist, 93, pp. 436–443
Levkowitz, H. (1997): Colour Theory and Modelling for Computer Graphics, Visualization and Multimedia Applications. Boston
Lindbloom, B. J. (2012): Useful Colour Equations. Retrieved November 12, 2012, from http://www.brucelindbloom.com/
Luo, M. R.; Cui, G., and Rigg, B. (2001): The Development of the CIE 2000 Colour-difference Formula: CIEDE2000. In: Colour Research and Application, 26, pp. 340–350
May, M. (2009): Sensation and Perception. New York.
Pascale, D. (2003): A Review of RGB Colour Spaces: from xyYto R’G’B. Retrieved from http://www.babelcolor.com/download/A review of RGB colour spaces.pdf
Pele, O., and Werman, M. (2012): Improving Perceptual Colour Difference using Basic Colour Terms. Computer Research Repository, abs/1211.5 (November), 1–14
Robertson, A. R. (1990). Historical development of CIE-recommended colour difference equations. In: Colour Research and Application, 15 (3), pp. 167–170
Robinson, A. H.; Morrison, J. L.; Muehrcke, P. C.; Kimerling, A. J., and Guptill, S.C. (1995): Elements of Cartography. 6th ed., New York
Roy, M.S.; Podgor, M. J.; Collier, B., and Gunkel, R. D. (1991): Colour Vision and Age in a Normal North American Population. Graefe’s Archive for Clinical and Experimental Ophthalmology = Albrecht von Graefes Archiv für Klinische und Experimentelle Ophthalmologie, 229 (2), pp. 139–144
Sharma, G.; Wu, W., and Dalal, E. N. (2005): The CIEDE2000 Colour-difference Formula: Implementation Notes, Supplementary Test Data, and Mathematical Observations. In: Colour Research and Application, 30 (1), pp. 21–30
Slocum, T. A.; McMaster, R. B.; Kessler, F. C., and Howard, H. H. (2008): Thematic Cartography and Geovisualization. 3rd ed., Prentice Hall
Stokes, M.; Anderson, M.; Chandrasekar, S., and Motta, R. (1996): Proposal for a Standard Default Colour Space for the Internet: sRGB. In Fourth Colour Imaging Conference: Colour Science, Systems, and Applications, pp. 238–245
X-Rite. (20 12): How Colour Notation Works. Retrieved February 13, 2012, from http://munsell.com/about-munsell-colour/how-colour-notation-works/
Xiao, F.; Cai, G., and Zhang, H. (2016): Segregation Analysis Suggests That a Genetic Reason May Contribute to “The Dress” Colour Perception. In: PloS One, 11 (10), e0165095
Yang, Y., Ming, J., and Yu, N. (2012): Colour Image Quality Assessment Based on CIEDE2000. In: Advances in Multimedia, 2012, pp. 1–6
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Alžběta Brychtová (alzbeta.brychtova@gmail.com) is an UX designer and cartographic visualization expert in Lufthansa Systems since 2016. Before, she was a postdoctoral researcher with the Geographic Information Visualization and Analysis group of the GIScience Center of the University of Zurich. She completed her PhD in Geoinformatics and Cartography at the Department of Geoinformatics, Faculty of Science, Palacký University Olomouc in the Czech Republic. During her PhD studies she was a visiting researcher at the ETH Zurich, University of Zurich and University of St Andrews (UK). Her primary resea rch interests are in cognitive and usability issues in geovisualizations.
Dr. Arzu Çötekin (arzu.coltekin@geo.uzh.ch) is a Research Group Leader and a Senior Lecturer at the GIScience Center of the University of Zurich and a research affiliate at the Seamless Astronomy group (which specializes in data science and scientific visualization) at Harvard University. Her interdisciplinary work covers topics related to GIScience, visualization, vision (perception and cognition), eye tracking, virtual environments, and human-computer interaction. She is an active member of several international commissions and working groups, specifically with the ICA and ISPRS, and chairs the ISPRS working group Geovisualization and Virtual Reality.
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Brychtová, A., Çötekin, A. Calculating Colour Distance on Choropleth Maps with Sequential Colours — A Case Study with ColorBrewer 2.0. j. Cartogr. Geogr. inf. 67, 53–60 (2017). https://doi.org/10.1007/BF03545377
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DOI: https://doi.org/10.1007/BF03545377