Re: [Groff] cmyk -> gray conversion

[Werner LEMBERG]

> > Does somebody know a conversion algorithm CMYK -> gray?  For RGB, I
> > use
> > 
> >   0.299r + 0.587g + 0.114b
> 
> Plugging the CMYK -> RGB algorithm into that gives:
> 
>       (1 - 0.299c - 0.587m - 0.114y)(1 - k)

Thanks, I'll use that -- my only concern is that, due to the various
RGB->CMYK algorithms, another (probably better) conversion routine
should be used.


    Werner