Radeon Contrast Changes
Changing Native LVDS Contrast on Thinkpads
The xvattr program can be used to change the contrast of videos being played with programs like wxvlc and mplayer.
Native LVDS Contrast on Radeon
On many thinkpad models, the LVDS panel contrast cannot be changed using standard tools. In Microsoft Windows, this is done with the proprietary ATI configuration program. However, neither fglrx nor the radeon driver can do this.
The best options to try is the ddccontrol program, which is quite old and probably will not work.
It seems the i2c interface could be used to do this, and that's what ddccontrol uses, could be used directly with programs like i2cset, but this seems not to work.