On 13 Nov 2002, Jason L Tibbitts III wrote: >Date: 13 Nov 2002 10:10:22 -0600 >From: Jason L Tibbitts III <tibbs@math.uh.edu> >To: xfree86-list@redhat.com >Content-Type: text/plain; charset=us-ascii >List-Id: Red Hat XFree86 list <xfree86-list.redhat.com> >Subject: Antialiasing blurs vertical font elements > >I'm finding that my RH8 machines have a peculiar issue with font >antialiasing. In previous releases, vertical font elements were >always rendered sharply, while antialiasing was used to smooth out >curves and diagonals. But in RH8, antialiasing is used to position >vertical font elements on the subpixel grid, and this results in >extremely blurry text. On an LCD panel with subpixel-AA turned on, >characters acquire colored shadows. For an example, see: >http://www.math.uh.edu/~tibbs/rh8-poor-fonts.gif I just looked at the picture above and it looks like straight antialiased fonts. I do not see any subpixel rendering effects or artifacts present in the image. This could be because you used xmag to magnify it possibly, if there are in fact artifacts. Magnification occurs at the pixel level, where a pixel is simply scaled in the x and y axes by some factor. It does not take into account the subpixelation of the display it is running on, and in fact has no idea how the physical display is generating the pixels on screen. It could be a CRT, or an LCD for all xmag knows. All magnification will do, is make the visible to the eye color of the entire pixel magnified. It will not separate the color components and magnify them out, keeping the subpixelation visible in the magnified view. If the above sounds confusing, there is a great article on this at: http://grc.com/cleartype.htm >Can anyone suggest a way to revert to previous behavior? My only >alternative seems to be turning AA off completely. Gnome seems to >have a tool, gnome-font-properties, that shows (under the "details" >panel) four levels of hinting, with "full" being the only one that >doesn't have the bothersome effect. But this tool has no effect on >non-Gnome applications. This suggests that there might be a way to >tweak /etc/fonts.conf somehow, but documentation of that file seems to >be missing. Not sure, as the gif above doesn't really show much IMHO. It looks like some of the stems are being antialiased on the sides, which looks just plain wrong in every way, but other than that, I see no subpixel rendering artifacts. -- Mike A. Harris ftp://people.redhat.com/mharris OS Systems Engineer XFree86 maintainer Red Hat Inc. _______________________________________________ xfree86-list mailing list xfree86-list@redhat.com https://listman.redhat.com/mailman/listinfo/xfree86-list IRC: #xfree86 on irc.redhat.com
