Hinting: M left vertical stroke anti-aliasing

[Wynand Winterbach]

24pt Regular M

I'm using Chrome 6 on Ubuntu 10.4 with Gnome. The text is being displayed on a 1280x1024 Dell 1908FP. My anti-aliasing settings are set to "Best shapes" in Gnome.

The capital "M" displays unpleasant anti-aliasing artefacts on its sides. This is no show-stopper, but it would be good if it can be modified to interact better with anti-aliasing.

Mozilla/5.0 (X11; U; Linux x86_64; en-US) AppleWebKit/534.3 (KHTML, like Gecko) Chrome/6.0.472.63 Safari/534.3

[Paul Sladen (sladen)]

It feels like we've had quite a few reports now about the M. The screenshot on this bug makes it look as though the 'M' has a definite "shoulder" on the left-hand side (note that this screenshot is taken with the manual hinting in-use).

The capital 'M' to me is one of the most stylised and important glyphs in the Ubuntu Font Family that give it its look and feel, to the point that it's the one picked to represent the font in the browser favicon:

  http://font.ubuntu.com/favicon.ico

Zooming into this screenshot we can see that on the right-hand outer stroke, the hinting snaps it to the pixel boundary on the *inside* edge, and allows a tiny bit of grey into the third pixel on the outside, whereas on the left-hand side the snap is occuring on the outside, rather than the inside.

Perhaps the solution is to move the snap to the inside on other side and allow a tiny bit of antialising past the outer pixel boundaries on bother sides.

[Matthew Paul Thomas (mpt)]

The original report says nothing about the left and right stems being different, and if you hadn't zoomed in I doubt you'd have noticed. :-) The "unpleasant anti-aliasing artefacts" on both sides are as I described in bug 651657: you expect the stem to be straight rather than a subtle curve, so with the limited information your eye gets you assume that the change in angle is caused by the anti-aliasing messing up. As I explained there, it can't really be fixed without fundamentally changing the shape of the M.