Font rasterization techniques

Posted Sep 25, 2007 1:43 UTC (Tue) by k8to (subscriber, #15413) [Link]

Yes, after having read the entire text, I see his entire thrust is that text, that is characters, need not be pixel-aligned. For a great many applications this type of layout seems superior, although I cannot help but feel the surrounding text provided by my browser is easier to read than any of his examples, though they may be more elegant.

In essence I think crappy pixel aligned text still has its place (such as in this edit box into which I am typing), but when the goal is to have any sort of font and page-layout fidelity, I'm convinced of his arguments.

Posted Sep 27, 2007 21:06 UTC (Thu) by Ross (subscriber, #4065) [Link]

It is actually much easier to do it that way, but it leads to text which looks blurry and lightened (try zooming out of a screenshot in an image viewer and notice how the text turns gray). (This could be accomplished with supersampling or vector-based calculation.) You get less spacial aliasing in exchange for blurriness.

It's a classic sampling theory problem.

Subpixel rendering of course refers to not treating the different LCD pixel elements as if they were at the exact same locaiton. You get better resolution at the cost of color fringing.

Some comination of the approaches is likely to produce the best results, which is why fonts have complex hinting attributes for handing pixel alignment at different sizes.

But this entire area is a patent minefield so Free Software developers don't have all that many options.