Re: [css-gcpm][css-color] device-cmyk() interaction with RGB-space colors.

On Thu, Sep 26, 2013 at 4:35 AM, Henrik Andersson <henke@henke37.cjb.net>wrote:

> Rik Cabanier skriver:
> >
> > 5. How to handle content that has an RGB only operation (such as a
> > colormatrix filter) during export to CMYK
>
> Wouldn't that particular filter make just as much sense as per channel
> blend modes? After all, it is a per channel operation. Kinda.
>

not really. Color matrix [1] uses a 4x5 matrix.
To do the same thing in CMYK, you'd need a 5x6 one.

PDF/Adobe allows you to see a colorspace for a blending operation but in
almost all cases it's the same colorspace as the document.


>
> It would obviously need a dedicated configuration for other color
> spaces, but the operation itself should make sense.
>
> Question is, has anyone actually tried using a color matrix on anything
> besides RGB? Not counting shenanigans to setup the matrix to convert to
> rgb before the main effect...
>

I'm not sure. I could ask our PhotoShop people.