Map color design for red-green color blindness
ISBN 978-85-88783-11-9
Authors
1Zhu, H.; 2Li, L.
1SCHOOL OF RESOURCES AND ENVIRONMENT SCIENCE WUHAN UNIVERSITY Email: hhzhu@whu.edu.cn
2SCHOOL OF RESOURCES AND ENVIRONMENT SCIENCE WUHAN UNIVERSITY Email: lilin@whu.edu.cn
Abstract
Maps, which are the carriers and transmission mediums of geospatial information, are important in our daily life. The technology of map-making has been changed revolutionarily with the development of science technology, especially that of the computer technology applied to the cartography. The varieties of maps have been enriched from the two-dimensional maps to the three-dimensional ones and from the static maps to the dynamic ones. In this development, one thing that should to be paid attention to is the feelings of different map users, especially to those who have the obstacle in reading a map. The color-blindness who is one part of these groups are unable to differentiate colors very well . They can hardly distinguish some colors, and may be confused by the colors and misunderstand the information expressed in the map. According to document that color-blindness takes up eight percent of total global population. Therefore, it is significantly that thinking about the characteristic of color-blindness in distinguishing between colors to design the map color. This paper aims to discuss the principle and the methodologies of designing chromatelopsia maps based on the features that how the most color-blindness distinguish colors. And it is also on purpose to design the maps which information can be easily read. In order to do these, two types of map were conducted experiments. Firstly, a tourist map was selected to study how represent the quality characters of the cartographic features in the map for the red-green color blindness. Analysis of the way of representing a tourist map, its characteristics and the color confusing ranges to red-green color blindness, we studied systematically on color design method of point symbols, line symbols and area symbols, and proposed a color expression methods based on the semantic categorization of the cartographic targets. Then we designed a tourist map for red-green color blindness. To valuate this tourist map effect, we took the questionnaire test. Subjects’ test result showed that it is more easy to read, and less misunderstand when red-green color blindness read this tourist map. Secondly, We select the Choropleth map to study on expressing the quantity characters of the cartographic features in the map for red-green color blindness. The experiment has been divided into several parts, including different grading levels, coloring with three-primary colors and coloring with confusing colors. Different choropleth map have been made. Test results showed that in the choropleth map ,which grade colored with three-primary colors, the red-green color blindness can easily get the correct information when they read the map, while in which grade colored with confusing colors, they can hardly distinguishing the grade level. and made more misunderstand. Base on the grade coloring experiment, we give some grade coloring suggest. Finally, the basic principles and the methods of coloring map are concluded based on the experiments of the tourist map and the choropleth map.
Keywords
Map color design; Red-green Color blindness; Tourist map