1/12/09 @ 09:16 (-0500), thus spake Michael Droettboom:
Subpixel rendering is almost never what you want when producing a
PNG file, since it is likely to be shared on a different machine
requiring different subpixel settings. But it looks like your
mozilla example is not using subpixel rendering either, though it
appears to have very strong hinting.
Yes, it's not a subpixel rendering problem. I can tell that
subpixel rendering is not enabled because I'm not seeing "rainbows",
which I always see when it's enabled. It's definitely a hinting issue.
matplotlib's Agg backends borrows a technique used by Adobe Acrobat
which is to use strong hinting in the vertical direction, but more
subtle hinting in the horizontal. When we did a comprehensive
comparison of various hinting options about two years ago it was the
strong winner. See this:
(Unfortunately, the linked images are no longer available).
If these settings are not to your liking, I would recommend the
Cairo backend (which should pull in the same settings as the rest of
your Gnome desktop, I believe), or one of the vector backends and
then tweaking the rendering.
Confirmed. The GTK backend -haven't tried Cairo yet- honours the
system settings for font rendering. It looks much better now, in my
Alternatively, we could provide this "stretched hinting" as a
configuration option. If you think that's superior to these other
options, please file a feature request so it doesn't get lost (and
it should be a fairly straightforward patch for someone new to the
Ok. I will open a feature request, if you think it's okay.
I think I'll be sticking with the GTK backend for now, anyway.