On Wed 06 Oct, Henrik Gedenryd wrote:
> The TrueType font rendering and antialiasing in Squeak is very cool. I 
> realized it would be quite easy to implement sub-pixel rendering, at least
> in a simple form.
Tres cool Henrik. Looks pretty good on my Apple LCD Studio Display...
> 
> If you haven't heard of it, sub-pixel rendering is when you manipulate the
> individual R, G and B cells of an LCD screen's pixels to achieve a 3x
> increase in horizontal antialiasing resolution, which makes especially text
> much sharper. In effect, you use the three cells of each pixel as
> independent pixels, and balance their colors so you don't notice that they
> are of different colors (like you don't notice that a white pixel is made of
> one red, one green, and one blue cell).
I don't think this is strictly true; or rather it's true but only part of the
story. Sub-pixel anti-aliasing doesn't have anything particularly to do with
LCDs and can be done on any display with a reasonably wide range of
colours/shades available. For example, it has been used on Acorn RISC OS since
'89 for everything from 640 at 480 4bpp screens up to 1600 at 1200 32bpp.
You _can_ actually improve the vertical resolution in just the same way as the
horizontal, but as you said, the micro-manipulation that colour LCDs need
doesn't help vertically. On CRTs and LCDs you can still do 'regular' anti-
aliasing in both axes. You can do it quite well on decent printers as well.


tim
-- 
Useful random insult:- Has the mental agility of a soap dish.
Tim Rowledge:  rowledge at interval.com (w)  +1 (650) 842-6110 (w)
 tim at sumeru.stanford.edu (h)  <http://sumeru.stanford.edu/tim>