Comments on: Font Smoothing in Pages http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/ Fri, 21 Nov 2008 20:02:18 +0000 http://wordpress.org/?v=2.5.1 By: skyfex http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11502 skyfex Fri, 10 Feb 2006 17:24:50 +0000 http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11502 I've bumped into similar problems with sub-pixel anti-aliasing when I've been developing. First of all, it often looks awful on dark background, but the main issue is transparent backgrounds. I've bumped into similar problems with sub-pixel anti-aliasing when I've been developing. First of all, it often looks awful on dark background, but the main issue is transparent backgrounds.

]]> By: Michael http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11498 Michael Wed, 08 Feb 2006 15:33:01 +0000 http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11498 <a href="http://www.michelf.com/weblog/2006/subpixel-antialiasing-achilles-heel/" rel="nofollow">Michel Fortin</a> has the answer: <blockquote cite="http://www.michelf.com/weblog/2006/subpixel-antialiasing-achilles-heel/">The “a” in aRGB stands for alpha — it’s the transparency value for the <em>whole</em> pixel. That’s it, the whole pixel: when aRGB pixels are later composited with other layers, each subpixels is mixed with the same level of transparency. This is incompatible with subpixel antialiasing which require a different transparency level for each of the three subpixels.</blockquote> Michel Fortin has the answer:
The “a” in aRGB stands for alpha — it’s the transparency value for the whole pixel. That’s it, the whole pixel: when aRGB pixels are later composited with other layers, each subpixels is mixed with the same level of transparency. This is incompatible with subpixel antialiasing which require a different transparency level for each of the three subpixels.

]]> By: RvU http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11495 RvU Mon, 06 Feb 2006 17:24:09 +0000 http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11495 It is very well possible to create an offscreen context that uses LCD antialiasing. I'm assuming it has to do with the color space you pass to CGBitmapContextCreate(). If it's the same color space that the display uses, then the context will use the same kind of font antialiasing. Maybe Pages and other apps use a generic RGB color space instead, which is a little easier to code - a single line of code instead of three. It is very well possible to create an offscreen context that uses LCD antialiasing. I'm assuming it has to do with the color space you pass to CGBitmapContextCreate(). If it's the same color space that the display uses, then the context will use the same kind of font antialiasing. Maybe Pages and other apps use a generic RGB color space instead, which is a little easier to code - a single line of code instead of three.

]]> By: Betalogue http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11488 Betalogue Sat, 04 Feb 2006 23:05:45 +0000 http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11488 Obviously my comments about the text rendering engine were pure speculation on my part. I am not a developer and have no idea how Pages works in that respect. All I know is that the end result is unacceptable, and Apple's refusal to fix it leaves the door open to speculation about its reasons/motives. Obviously my comments about the text rendering engine were pure speculation on my part. I am not a developer and have no idea how Pages works in that respect. All I know is that the end result is unacceptable, and Apple's refusal to fix it leaves the door open to speculation about its reasons/motives.

]]> By: Michael http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11487 Michael Sat, 04 Feb 2006 20:48:43 +0000 http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11487 Matt: Right. I'm saying that it would be hard for an application developer to fix this without help from Apple (in the form of an additional CGContext function). Why isn't there such a function already? It's obviously desirable and seems easy to add, so it's either a glaring oversight or a harder problem than it seems. Matt: Right. I'm saying that it would be hard for an application developer to fix this without help from Apple (in the form of an additional CGContext function). Why isn't there such a function already? It's obviously desirable and seems easy to add, so it's either a glaring oversight or a harder problem than it seems.

]]> By: mdeatherage http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11486 mdeatherage Sat, 04 Feb 2006 19:38:48 +0000 http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11486 I don't know why this would be hard to fix at all - add a new API that sets the font smoothing "method" for a given CGContext and you're done, right? Isn't that the benefit of the CGContext being an opaque type? I don't know why this would be hard to fix at all - add a new API that sets the font smoothing "method" for a given CGContext and you're done, right? Isn't that the benefit of the CGContext being an opaque type?

]]> By: Ben Lings http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11485 Ben Lings Sat, 04 Feb 2006 18:27:47 +0000 http://mjtsai.com/blog/2006/02/04/font-smoothing-in-pages/#comment-11485 Another (possibly related) place this happens is with the menu extras - these also don't use the system setting, but use the CRT setting instead. Another (possibly related) place this happens is with the menu extras - these also don't use the system setting, but use the CRT setting instead.

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