weight vs colour [LWN.net]

weight vs colour

Posted Aug 10, 2012 10:02 UTC (Fri) by pjm (guest, #2080)
In reply to: Adobe ventures into open fonts by alankila
Parent article: Adobe ventures into open fonts

Regarding shearing changing the weight of the font, I think this should be accompanied by noting that the overall typographic colour theoretically won't change: that is to say, the mathematical area that's black won't be affected by shear, any strokes that become thinner will also become longer.

So a shear-italicized large region of text shouldn't become any darker or lighter when glancing at a page or seen from the corner of one's eye, it should only change how thick the strokes look when directly reading the italicized text.

That's a theoretical argument, and assumes that typographic colour can be measured by a simple mathematical expression (proportion of area), and also ignores the effect of ink bleed on paper, or hinting or gamma issues on screen.

Does anyone know of a better objective measure of typographic colour ?

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weight vs colour

Posted Aug 10, 2012 18:09 UTC (Fri) by alankila (guest, #47141) [Link] (1 responses)

That is an enlightened comment.

You are absolutely right that the shear does not actually change the average color of the glyph in its box, even if you would subjectively evaluate the width of the slanted line as thinner than the straight line.

Proper implementation of font blending gets gamma right, even if linux software that does it correctly is very scarce -- in fact nonexistent would be more accurate. As an aside, I was able to get sRGB surface support in the 0.27.2 release of pixman, though, so maybe if I make more noise about this people start to use sRGB surfaces when blending text...

weight vs colour

Posted Aug 16, 2012 22:25 UTC (Thu) by njs (subscriber, #40338) [Link]

How does using sRGB surfaces help? sRGB isn't linear-light... right? Or is it just that when a surface is labeled sRGB then that gives a good excuse to also turn on linear-light alpha composition as well?