Enabling sub-pixel rendering for LCD display

Problem

When using the digital output (DVI port) on the LCD monitor, the texts might exhibit a ghosting or blurring effect.

Solution

This may be due to an incorrectly configured font subsystem. In particular, the subpixel hinting may be disabled or misconfigured. The following thread on the redhat-list describes the problem in some detail:

https://www.redhat.com/archives/redhat-list/2004-January/msg00588.html

To enable sub-pixel hinting under KDE:

  1. Open the Control Center
  2. Click on Appearence and Themes
  3. Check Use anti-aliasing for fonts
  4. Click on Configure
  5. Check Use sub-pixel hinting
  6. Select the correct pixel ordering for your LCD (usually RGB or BGR)
  7. Select Full hinting
  8. Close the Control Center and restart the X Server

To enable sub-pixel hinting under GNOME:

  1. Select Preference from the application menu
  2. Open the font panel
  3. Select Sub-pixel smoothing
  4. Click on Details
  5. Select Full hinting
  6. Select the correct pixel ordering for your LCD (usually RGB or BGR)
  7. Close the font panel and restart the X Server

It may be necessary to try several sub-pixel settings to find the optimal settings for a particular display.