Previous PageNext Page

4.2. Color tables

A colour table contains six tab-delimited fields. The first line describes the fields.

Here is an example:

From To Red Green Blue Files
0 5 255 255 255 Clouds
6 92 255 226 201 Bare Soil
93 110 255 211 150  
111 118 255 255 176  
119 127 211 255 125 Sparse Veg
128 137 201 255 201  
138 147 176 230 176  
148 158 140 211 140 Light Veg
159 168 100 176 100  
169 181 75 150 75 Medium Veg
182 195 50 125 50  
196 210 25 100 25  
211 254 0 75 0 Heavy Veg
255 255 128 128 128 Water

FROM and TO are the range of image values to be assigned to a color or data ranges for a map. For an image, these values must be in the range of 0-255 and correspond to the actual digital counts, not the derived values such as NDVI. The values should not overlap between colors. Also, the FROM value in a color should be one greater than the TO value in the previous color.

RED, GREEN and BLUE are the intensities of the respective primary colors in the range of 0-255.

LEGEND is an optional text field that will be displayed along-side the colors in the legend.

For further information concerning colortables, see § 2.4.5.


Previous PageTop Of PageNext Page
This manual was prepared by the Global Information and Early Warning System of the United Nations Food and Agriculture Organization
© FAO/GIEWS - 1999
E-mail: Giews1@fao.org