RE: [Freetype] Arial.ttf with no anti-aliasing problem...

[Michael Jansson]

We are using Freetype 2.0.5 as well, without the problem you are seeing so
it looks like you have a few bugs to track down!?

btw - Are you aware of the use of the GASP table in OpenType? It contains
information about at what sizes Mozilla is supposed to use b/w, grayscale
and hints. Turning on hints at all sizes, or grayscale at all sizes is not a
good idea. I do not believe that Freetype uses this table for you (and it
should not), so you need to read this table yourself and use it
appropriately.

Some fonts, e.g. hollow/outlined, very light fonts and script fonts are way
to light to be gray scaled at smaller sizes. You end up with light gray
pixels that are not legible at all (e.g. the strokes of the characters are
less than 1/8 of a pixel, making them almost white). Also, hinting at _very_
small sizes (e.g. below 7px) usually produce bad results, so a GASP table
would typically tell you to do grayscales but no hints below a certain size.
In the mid range (e.g. 8-15px), you usually don't want to do grayscales as
it produces too many gray pixels it relation to black pixels, which makes
the glyph look fuzzy (there are some debates on this). At larger size you
typically want both hinting and gray scaling.

Don't use global thresholds for all fonts. It's doesn't work. Just look at
what Apple did with OS9 (yikes!). These thresholds are set on a per font
basis for a reason.

Anyway, use the 'gasp' table if you are not already using it. More info at:
http://www.microsoft.com/typography/otspec/gasp.htm

Regards,
em2 Solutions
Michael Jansson

> -----Original Message-----
> From: Brian Stell [mailto:address@hidden
> Sent: Thursday, December 13, 2001 12:41 AM
> To: address@hidden
> Subject: Re: [Freetype] Arial.ttf with no anti-aliasing problem...
> 
> 
> oops, I reveresed the image and bug:
> 
> I posted the image here:
> http://bugzilla.mozilla.org/attachment.cgi?id=61480&action=view
> 
> as part of this bug:
> http://bugzilla.mozilla.org/show_bug.cgi?id=114885
> > 
> > Antoine Leca wrote:
> > >
> > > HI Niels,
> > >
> > > Niels Moseley wrote:
> > > >
> > > > I'm having problems with the Arial.ttf font at small 
> sizes.. I am
> > > > currently using Freetype 2.0.5 with the bytecode 
> interpreter enabled
> > > > (compiled using the Borland CBuilder 5.0 compiler).
> > > >
> > > > Even the supplied example programs ftstring and ftview 
> display the font
> > > > rather badly.
> > >
> > > What is the command line you use (or in other words, what 
> is the point
> > > size you ask for)?
> > >
> > > > I've tried a host of things like enabling and disabling 
> hinting [...]
> > >
> > > Does it works? (i.e., does the drawing change?)
> > >
> > > Antoine
> > >
> -- 
> Brian Stell
> 
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