Re: [ft] rendering changes 2.1.10 -> 2.2.1

[David Turner]

Hello Gordon,

thanks for the clarification; it seems that you're saying that:

A) "light" hinting now produces fuzzy glyphs
B) "medium" hinting used to provide better output that previously

well, first of all, A) is purely intentional since we modified the
algorithm to get results that are consistently closer to the original
shapes than previously. The result is indeed fuzzier, though this is
minimized when using proper LCD filtering. This is also more or less
equivalent to what you get on Mac OS X

for B), I'm quite surprised because the algorithm for medium hinting
in FreeType didn't really change between these two versions. Besides,
I'm more interested in knowing what you think about the current CVS
hinting changes

Hope this helps,

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


On Thu, 16 Nov 2006 08:33:27 -0800, "Gordon Messmer" <address@hidden> said:
> David Turner wrote:
> > There are indeed differences in the auto-hinter between various
> > FreeType releases, since we try to enhance it incrementally (and
> > this will be true for the next release, by the way, which should
> > treat serif fonts much better, try the CVS if you want).
> 
> I'll give that a shot soon.
> 
> > I fail to see exactly what the problem is; you're not even providing
> > screenshots nor telling what is wrong, only that things are "different".
> 
> OK, I didn't describe the problem, as I perceive it, until the end. 
> "where Medium hinting used to provide very pleasing results, it
> now seems to squish characters vertically, and they're fuzzy"
> 
> I've included a set of screenshot selections showing the Gnome terminal 
> using Courier and Luxi Mono.  In each shot, the upper terminal is using 
> freetype 2.2.1, and the lower one is using 2.1.10.  In the "best 
> contrast" shots, both appear identical.
> 
> In Courier-12-BestShapes, the fonts in the upper terminal look fuzzy. 
> Magnify the word "Monospace" in the image.  You can see clearly in the 
> 'M', 'n' and 'p' characters in the lower terminal have good, solid 
> vertical stems.  They're one pixel wide and relatively solid in color. 
> In the upper terminal, those characters have two-pixel wide stems that 
> fade into the black background.  This difference makes them appear very 
> fuzzy.  All of the characters in the upper terminal appear fuzzy, 
> regardless of whether or not they have vertical lines.  The old 
> rendering model did a better job, here, with medium hinting.
> 
> In LuxiMono-10-BestShapes, the fonts in the upper terminal appear fuzzy, 
> again.  Vertical stems tend to be more faded in color, where they used 
> to be bright.  The 'g' character also looks vertically squished where it 
> used to have a well rounded shape.
> 
> I can provide more shots, with different fonts, if you'd like.  In 
> general, though, all of the fonts that I look at appear to look better 
> with medium hinting in 2.1.10.
> 
> Is there an easier way to test various hinting levels?  I don't see 
> options within ftview to do anything other than turn hinting on or off...
> 
> Thanks for looking at this.
>