Sub-pixel positioning

Sven Langkamp longamp at
Wed Mar 17 19:19:33 CET 2004

Am Tuesday 16 March 2004 20:08 schrieb Boudewijn Rempt:
> > It's quite a simple change, especially if we're going to turn CMYK into
> > RGBA before compositing, as mentioned in the alpha plan. Exactly how
> > alpha interacts with non-RGB colour spaces and compositing is a bit
> > unclear, or at least, requires some thought.
> It was meant to elicit some discussion. The advantages of rendering each
> layer to rgba before layer compositing are clear: it means you can
> basically combine anything with anything, if needs be even, eventually,
> karbon layers or whatever. The disadvantage is that I'm not sure what
> combining, say, cmyk, in rgba space is going to compared to combining as
> cmyk.
I think the problem would be that every conversion would cause a loss of 
quality. If the error of the conversion algorithm is very small this wouldn't 
be a problem. The error also gets bigger if there are many layers.
Did anybody try out how big the error is?

btw: This is also a reason why we can't use KoColor for the paint color. It 
simply has no real CMYK-to-RGB conversion (I discovered this when I tried out 
a CYMK color chooser)

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