Problem with KisAbstractColorspace::difference

[Boudewijn Rempt]

On Thursday 26 January 2006 19:56, Cyrille Berger wrote:
> > It uses deltaE which is an international standard, based (to a degree) on
> > perceptual input from actual persons.
> >
> > However, it is most accurate when colors are close, so the extremes you
> > describe are not handled very well.
> >
> > If we can find a way to provide better long distance accuracy while
> > retaining close accuracy too - it would be great.
>
> And I found a page where they seem to prove that deltaE is a bad measure
> anyway (I don't know if they are right or no, I don't know enought about
> color ;) ) :
> http://www.aim-dtp.net/aim/evaluation/cie_lab/index.htm
>
> And lcms use an outdated DeltaE function :
> http://www.brucelindbloom.com/index.html?Math.html
> New version might be more accurate, but they ask more calculation and I am
> not sure they answer correctly to our problem.
>
> And for RGB, I think (abs(r1-r2) + abs(g1-g2) + abs(b1-b2))/3 might work,
> but equivalent function for CMYK will be wrong.

Maybe something to ask on the lcms mailing list, too?

-- 
Boudewijn Rempt 
http://www.valdyas.org/fading/index.cgi
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