OpenWindows Advanced User's Guide

10.5.1.1 Calibrated Profiles and Visuals

When Calibrator Tool calibrates your monitor it produces one calibrated profile for each frame buffer's visual. When images are displayed on a monitor, two conditions may exist that affect whether the resultant color appears the same on two different devices: the slow shifting of color and the use of X visuals.

Recalibrating corrects the slow shifting of color. Your frame buffer's hardware gamma lookup table (LUT) corrects X visuals. A visual is a data structure describing the display format a display device supports. The visual describes the display characteristics for each pixel in the window. In other words, a window's visual instructs the display device's hardware gamma LUT how to interpret the value of the window's pixels. When the visual goes through the gamma LUT, it is then corrected.

If the KCMS software calibrates a corrected X visual, the resultant color will not appear the same on two different devices because the visual will be gamma corrected twice. The KCMS software determines if the X visual has been corrected with a hardware gamma LUT to ensure color consistency. For more information on X visuals and hardware gamma LUTs, see the xgetvisualinfo(3) and xsolarisgetvisualgamma(3) man pages.

The calibrated profile that describes your monitor is copied to the /etc/openwin/devdata/profiles directory. Read-only nominal profiles are in /usr/openwin/etc/devdata/profiles.

A copy of the profile you select with Calibrator Tool (see "10.5.4.2 To Select a Monitor") is made for each type of color visual supported by your frame buffer. GrayScale or StaticGray visuals are not considered because they are not color visuals. If your frame buffer supports both PseudoColor and TrueColor visuals, two or more sets of measurements will be taken by Calibrator Tool.