Colour Management notes for Windows XP SP2

Colour Management notes for Windows XP SP2

This article describes programs and settings under Windows XP SP2 used in colour management. Other versions of Windows will probably behave differently. Please note that this article is based on testing with my own equipment, other hardware may behave differently.

Computer monitor settings affect projectors

When you connect a projector to computer and have the same display on both (cloned view) then settings made for your computer monitor affect the projector.

If you have installed Photoshop and/or colour management software, then two aspects of your computer system will probably have been changed:

Both of these changes are specific to the computer monitor and will not be appropriate for the projector. [Unless you have computer monitor that can internally calibrate to sRGB]

Assuming the projector is internally calibrated to the sRGB standard:

[When Photoshop is installed, it also installs Adobe Gamma which is a basic colour management calibration utility.]

What colour management software does

Colour management software for a computer monitor does two main jobs:

A profile for your monitor is created by the software and contains both:

Monitor profiles are used at two different times

Generally, the profile used for these tasks is identified by the Default Monitor Profile setting in Windows (Display Properties / Settings / Advanced / Color Management).

Other settings that affect the display

Aside from changes made to the LUT, the video card driver usually has global colour adjustment settings for people to play with that make their screen more pleasing. Unfortunately these settings come at the cost of reduced display quality when using colour managed software. These driver settings are usually accessed through the contol panel applet for the card - they should be at default values - values that don't modify the display.

LUT Loaders

The LUT loader program loads values from the monitor profile that was created last time you profiled your monitor. It is installed when you installed your colour management software. Adobe Gamma installed with Photoshop is also a LUT loader.

You should only have a single LUT loader run at startup. Check your All Users startup programs folder for shortcuts to the LUT loader(s).

Microsoft Color Control Panel Applet

The applet has some useful features:

Colour behaviour of application software

As mentioned above, colour managed programs like Adobe Bridge will gamut map colours suitable for the display device. However, this only happens accurately if the images displayed have been tagged with image's colour space. Programs that are not written using colour management do no conversion and send the pixel colours directly through the display system.

Consider these scenarios assuming the system is set up as described above and the software is Adobe Bridge:

Now compare with these scenarios assuming the display system is set up as described above and the display software is IrfanView version 4 (not colour space aware):

Summary

For colour accurate display with an sRGB projector:

See also

Color management and color science: Introduction