Re: [ft-devel] gamma correction and stem darkening

[Derek B. Noonburg]

On 2016 Jan 16, Werner LEMBERG wrote:
> 
>>> For high-quality output with gamma correction, I think I need both:
>>> (1) native hinting for TrueType fonts -- otherwise tricky CJK fonts
>>>     fail
>>> (2) stem darkening -- otherwise the text is too light after gamma
>>>      correction
> 
> What you want doesn't exist yet, sorry, but I think this will
> eventually come.

Yup, I was pretty sure this full solution didn't exist yet.

But I was wondering if there are any other options -- assuming I'm using
FreeType 2.6.2, and I have proper gamma handling in my code.

I guess I could use stem darkening only for CFF fonts, and then
artificially darken the FreeType output for TrueType fonts.  By
"artificially darken", I mean take the FreeType output and run it
through a lookup table that darkens it.  It's a kludge, but it would be
very similar to the current situation (without correct gamma), I think.

On 2016 Jan 16, Nikolaus Waxweiler wrote:
> Your best bet is probably to find ways to detect tricky fonts somehow or 
> postpone your work to a future release. No idea which one, though...

Unfortunately, I don't think it will be possible to detect the tricky
fonts.  The issue is that PDF generation software is of varying quality
(to put it politely), so there are lots of PDF files out there with font
subsets that have no font names (not to mention other font syntax
problems), and I need to be able to render them.

- Derek