Re: RGB to CMYK
- To: mathgroup at smc.vnet.net
- Subject: [mg25538] Re: RGB to CMYK
- From: "Hans Staugaard" <hans.staugaard at get2net.dk>
- Date: Sat, 7 Oct 2000 03:35:42 -0400 (EDT)
- References: <8rjik5$odn@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hello Just use the "secret" function ToColor: In[1]:= ?ToColor "ToColor[color, form] converts color to form if form is GrayLevel, RGBColor \ or CMYKColor color is converted into it. Otherwise form[color] is evaluated \ and the result is expected to be a valid color directive." In[2]:= ToColor[RGBColor[1, 0, 0], CMYKColor] Out[2]= \!\(CMYKColor[5.46908`*^-6, 0.9958244690799987`, 0.9958244690799987`, 5.46908`*^-6]\) Hans "Bernd Brandt" <bernd at bio.vu.nl> wrote in message news:8rjik5$odn at smc.vnet.net... > Hi Group, > > I am looking for a conversion function between RGB and CMYK. > I thought this would not be a problem but i have not found one good function. > > The Mathematica book (examples) includes: > > CMYKfromRGB[RGBColor[r_, g_, b_]] := > CMYKColor[b, r b, 1 - b, (r + g + b)/3] > > But this is not correct. > RGBColor[1,0,0] really red, is converted to CMYKColor[0, 0, 1, 0.5], > which is clearly not red. > > Does someone have a correct function? > > > Regards, > Bernd > > >