Re: coverage to alpha

[Alexei Podtelezhnikov]

> > Coverage == opacity (aka alpha). It is more than plausible, it
> > is justifiable.
>
> And the justification is?

Let there be background light shining through the uncovered part or
the pixel! In whatever the wavelength is there in the background, may
I add.
Let the covered part shine with its own spectrum. :) We shall mix them
proportionally without altering the spectrums! Ta-da-da-dam!

> That is going to involve some kind of
> processing/interpretation by the visual system since the stimulus is
> different.

I know, the color perception is mysterious, but I am only concerned
with passing the correct signal to the monitor pixels, not beyond. :)
There are so many colorblind people too. What helps them is
appropriate color palette -- *not* opacity, *not* alpha, *not*
coverage.

> It is also well known that using the same alpha map, white text on black
> background does not create the same perception as black text on white
> background.

I beg to differ again. This is not about opacity, or alpha, or
coverage. It is actually about gamma correction and the choice of
colors. I bet you would love to play with our ftstring tool of
freetype-demos. It lets you play with gamma and offers a set of
different color combinations. You'll be amazed how much gamma matters.