Ubuntu Manpage: d.colors - Allows the user to interactively change the color table of a raster map layer

NAME

       d.colors   - Allows the user to interactively change the color table of a raster map layer
       displayed on the graphics monitor.

KEYWORDS

       display, raster

SYNOPSIS

       d.colors
       d.colors help
       d.colors map=string  [--verbose]  [--quiet]

   Parameters:
       map=string
           Name of raster map

DESCRIPTION

A color table file associates specific colors with the categories of a raster map layer.
The user can change these map category color assignments (i.e., change the map's color
table) interactively, by first displaying the raster map to the graphics monitor and then
running the program d.colors.

Any color changes made using d.colors will not immediately be shown on the graphics
display; however, any color changes saved will still alter the map's color table and will
appear next time the raster map layer is redisplayed (see d.colortable).

The user must first display the relevant raster map layer to the active frame on the
graphics monitor (e.g., using d.rast) before running d.colors. The user can then either
enter the name of the raster map layer whose color table is to be changed on the command
line (e.g., by typing: d.colors map=soils), or type d.colors without program arguments. If
the user simply types d.colors without program arguments on the command line, d.colors
will ask the user to enter the name of an existing raster map layer using the standard
GRASS interface.

In either case, the user is then presented with the d.colors command menu, shown below.
The d.colors commands are listed beneath the Category Pointer Movement, Color
Modification, Replotting Screen, and Quitting sections below. Commands are invoked by
typing in the single-key response shown to the left below. (Longer descriptions of these
commands appear to the right.) Results from invoking these commands will be reflected in
the Category and Category Number sections of the d.colors screen. On the d.colors screen
menu, commands appear in the right half of the screen, and the current status of
categories appears in the left half of the screen.
CATEGORIES
0 No Data
1 (Category 1 description)
2 (Category 2 description)
. ....
. ....
CATEGORY NUMBER:
RED 0 0%
GREEN 0 0%
BLUE 0 0%
Shift Incr: 10 3%
CATEGORY POINTER MOVEMENT
D/d down (cats) Move pointer to next category
U/u up (cats) Move pointer to previous category
COLOR MODIFICATIONS
R/r RED Increase/decrease RED intensity
G/g GREEN Increase/decrease GREEN intensity
B/b BLUE Increase/decrease BLUE intensity
I/i increment Increase/decrease increment
(of intensity shift)
h highlight Highlight current color
+/- shift colors Shift entire color table (up/down)
c save color Save color table
t toggle table Toggle to different color table
REPLOTTING SCREEN
* Replot screen Replots the screen
QUITTING
Q quit Quits program
Changing categories - The keys "d, D, u," and "U" are used to move to a different
category. The lower case letters move up, u, and down, d, the category list one category
at a time. The upper case letters move 10 categories at a time for fast movement. The
cursor does wrap between the first and last categories. The current category is noted on
the text screen with an arrow, and is indicated on the graphics screen by a box around the
current color.

Changing colors - The color associated with the current category can be changed with the
"R, r, G, g, B," and b keys. The upper case letters increase the intensities of red R,
green G, and blue B for the current category; the lower case letters decrease the
intensities of these same colors for the current category. Video devices make all the
colors of the spectrum by mixing red, green, and blue. For those accustomed to red,
yellow, and blue being the primary colors, this can be confusing. For starters, yellow is
made by mixing red and green. The intensities are listed on the text screen in as
percentages.

Keys I and i increase and decrease the percentage change that each keystroke of one of the
color keys (R, r, G, g, B, b) causes in its respective color. The increase increment is
initially set to 10%. Thus, pressing the R key would will increase the red component of
the current category by 10%.

Highlight - The h key toggles between the current category color and the current highlight
color. This color is initially black but can be modified as above while in highlight mode.
Blinking can be accomplished by repeatedly striking the h key. When changing to different
categories using the movement keys as described above, while in highlight mode the
category colors will be always left showing their actual colors. Only one category is
highlighted at any one time.

Saving the current color table - Pressing the c key will save the current color table as
you have modified it. This table will then be used next time you display or paint this
raster map layer.

Color table toggle - Different types of color tables are suitable for different raster map
layers. The key t flips between the following color tables: red, green, blue color ramp;
gray scale; smooth changing color wave; random colors; and the saved color table.

Color table shift - The entire table is shifted up and down using the + and - keys.

Quitting the d.colors program - Pressing the Q key will cause you to quit the d.colors
program. If colors have been modified but not saved, d.colors will ask:
Colors changed
Save the changes? (y/n)
The user should type in y to save changes, or n to not save changes, before quitting the
program. If the user types n, the program will ask:
Quit anyway? (y/n)

NOTES

       The map whose color table is to be altered with d.colors must already be on display in the
       active  display  frame  on  the  graphics monitor before d.colors is run. This can be done
       using the command d.rast map=name (where name is a raster map layer whose color table  the
       user wishes to alter).

       Some  color  monitors  may not support the full range of colors required to display all of
       the map's categories listed in the map's color table.  However, regardless of whether  the
       user  can  see  the color changes he is effecting to a map's color table, any changes to a
       map's color table made with d.colors that are saved will appear in the map's color table.

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