Using Help
|
Contents
|
Index
Back
100
Adobe Photoshop Help
Working with Color
Using Help
|
Contents
|
Index
Back
100
Customizing indexed color tables (Photoshop)
The Color Table command lets you make changes to the color table of an indexed-color
image. These customization features are particularly useful with
pseudocolor images
—
images displaying variations in gray levels with color rather than shades of gray, often
used in scientific and medical applications. However, customizing the color table can also
produce special effects with indexed-color images that have a limited number of colors.
Note:
To shift colors simply in a pseudocolor image, choose Image > Adjust, and use the
color adjustment commands in the submenu. For a summary description of these
commands, see
“Basic steps for correcting images” on page 129
.
Using the color table to edit colors and assign transparency
You can edit colors in the color table to produce special effects, or assign transparency in
the image to a single color in the table.
To edit colors in the color table:
1
Open the indexed-color image.
2
Choose Image > Mode > Color Table.
3
Click or drag in the table to choose the color or range of colors you want to change.
4
Choose a color, as explained in
“Using the Adobe Color Picker” on page 261
, and
click OK.
If you are changing a range of colors, Photoshop creates a gradient in the color table
between the starting and ending colors. The first color you choose in the Color Picker is
the beginning color for the range. When you click OK, the Color Picker reappears so that
you can choose the last color in the range.
The colors you selected in the Color Picker are placed in the range you selected in the
Color Table dialog box.
5
Click OK in the Color Table dialog box to apply the new colors to the indexed-color
image.
To assign transparency to a single color:
1
Choose Image > Mode > Color Table.
2
Select the eyedropper, and click the desired color in the table or in the image. The
sampled color is replaced with transparency in the image.
Using predefined color tables
Your indexed color table can be modeled after predefined color tables, which you select
from the Table menu in the Color Table dialog box.
Custom
Creates a palette you specify.
Black Body
Displays a palette based on the different colors a blackbody radiator emits as
it is heated—from black to red, orange, yellow, and white.
Grayscale
Displays a palette based on 256 levels of gray—from black to white.
Spectrum
Displays a palette based on the colors produced as white light passes through
a prism— from violet, blue, and green to yellow, orange, and red.
