Re: [ft-devel] Subpixel without patents

[David Turner]

Hello Kim,

I do not share SubLCD's author opinion regarding the fact
that his method doesn't infringe on *any* ClearType patent
claim, given that some of them are absurdly general. You
could still find prior art to invalidate them, but this
takes time, and wouldn't prevent Microsoft from suing for
infringement, knowing fully well that small companies will
cave in instead of paying the corresponding legal fees.

Moreover, a simple application of the technique creates
visible color fringes. the author states that we should
just "live with it", something I can't agree with. And
I don't think there is a filtering method that would
not infringe at this point, for the same reason described
previously. I would love to be proven wrong though.

Unless you can come up with arguments or prior art that
are defendable on a trial, I'm not going to jeopardize
the project's legal status.

For now, just consider that the technique is not available
for general usage, like MP3 decoding, and requires a patched
version of FreeType to be used. Nothing really new here.

If we find sufficient prior art, we may find someone willing
to fund a patent claim invalidation request later in the
future though.

Hope this helps,


- David Turner
- The FreeType Project  (www.freetype.org)

PS: By the way, I'm sorry to say that the same reasoning,
in my opinion, applies to the ClearScale image scaling
method.


On Mon, 16 Apr 2007 13:36:38 +0200 (CEST), address@hidden said:
> SubLCD is a non patented subpixel method:
> 
> http://oyhus.no/SubLCD.html
> 
> Perhaps useful for freetype?
> 
> Kim Øyhus
> 
> 
> 
> 
> _______________________________________________
> Freetype-devel mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/freetype-devel