Table of Contents
Advertisement
Setting the Defaults for White Point, Gray Point,
Black Point, and Auto Contrast
The Advanced Color Tab
Using the Advanced Color tab, you can specify output colors
for the black, white, and gray points and change the size of the
area sampled when the eyedropper tools in the Curves palette
are used. You can also adjust the portion of the tone range
excluded in autocontrast operations.
Reference: Preferences
White-Point, Gray-Point, and Black-Point Calculations
Using the RGB, CMYK, and Grayscale sheets, you can specify
default output values for white, gray, and black points in the
Curves palette for each of the RGB, CMYK, and grayscale color
spaces. The factory default settings for the white point in RGB
and grayscale are 255 for each channel, which displays as white
on most computer monitors. The factory defaults for the gray
point are 128 for each channel, which displays as a neutral gray,
while the defaults for the black point are zero for each channel,
which displays as black. In the case of CMYK, the factory de-
faults for the white point are 0% for each channel, which means
that true whites will be the same color as the paper when printed
on a four-color printer. The gray point for CMYK defaults to
50% for each channel, the black point to 100% for each channel.
To restore factory defaults for the color model in the selected
sheet, click the Reset button.
Although values for RGB and grayscale range from zero to 255
(with larger values representing brighter shades), calculations
are performed at a precision of sixteen bits. Values for CMYK
range from 0%–100%, with smaller percentages representing
brighter shades.
134
Advertisement
Table of Contents
