Bob Ebert wrote in message <12886@palm-dev-forum>...
>
>At 1:43 AM +0200 05/27/00, Eric Snider wrote:
>>Have any of you been working on sub-pixel rendering on the Palm IIIc?
>
>We looked at it. And decided it wasn't worth the trouble.
>
>Sub-pixel font rendering works fairly well for relatively large point sizes
>of italics text on a relatively high dot pitch (100dpi+) LCD display.
>You'll notice all the demos emphasize this. :-)
>
>Palm devices use relatively small point sizes of text, don't use italics at
>all, and have a lower dot pitch display. So it's not exactly appropriate
>technology.
>
>Sub-pixel rendering also increases the complexity of drawing text and
>requires larger font data. This means more CPU cycles and larger ROMs,
>which untimately means shorter battery life and slower devices. Text
>drawing is already one of the slowest blitting operations on the Palm
>devices...
>
>And, finally, the visual effect isn't actually very good on a IIIc! Take a
>sub-pixel rendered image off one of the websites and load it into an image
>viewer and you'll see what I mean. The relatively large pixel size of the
>IIIc display means you can actually see the color banding, which is not
>attractive.
>
You would be better off w/ an older technology, called "anti-aliasing".
That technology used shades of gray in addition to black and white,
which blended quite nicely producing the illusion of smoother lines.
Perhaps sub-pixel rendering works when the color elements are too
small to percieve individually, but anti-aliasing works even w/ larger
display elements.
The downside is that designing an anti-aliased font is somewhat
counter-intuitive, and is almost an art form. They have an example
on the page discussing sub-pixel rendering (http://grc.com/ctwhat.htm),
take a look and you will see what I mean. Its hard to believe that
that mess looks better than the starkly defined black&white glyph,
but it really does, honest.
--
-Richard M. Hartman
[EMAIL PROTECTED]
186,000 mi/sec: not just a good idea, it's the LAW!
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