Daniel Egger <[EMAIL PROTECTED]> writes:

> Am 06 Sep 2001 12:56:46 +0200 schrieb Sven Neumann:
> > I think Branko is right here. Color-To-Alpha is not suited for
> > chroma-keying since it will remove all shades of blue from all
> > colors in the image. Classic blue-boxing requires to clear only
> > exactly the color defined as the blue-box background. This can
> > easily be achieved using Select-By-Color with a small threshold
> > followed by Clear.  
> I believe a good chroma keying algorithm would have to work a bit
> differently because in real life one has the problem that the blue of
> bluebox might vary slightly because of lighting conditions. So maybe the
> best would be to go over the HSV colorspace to allow a choosable
> variance in the keycolor?

Select_By_Color takes care of that but operates only in the RGB domain.
It might be a good idea to add an option that allows to apply the
threshold to the HSV colorspace. If someone wants to hack this simple
function, please port by_color_select to libgimpcolor and add generic 
color_distance functions to libgimpcolor.

Salut, Sven
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