How to convert RGB to CMYK color?

[Young Ha]

Thanks for reading my trash...

If you know how to convert RGB color to CMYK color, please let me know that precious how-to.

[Sean]

I hope this table makes sense..........

............R..........G...........B
C..........0.........255.........255
M........255.........0..........255
Y.........255.......255...........0
K...........0...........0............0

[Young Ha]

Thanks a lot Sean.

Your advice is correct in theory.
What I need is practical conversion formula in printing using CMYK Inks. For example, commercial graphic softwares like photoshop are using very complex conversion math, which I wanna know.

Anyway, thanks for your kind advice and I truely appreciate it.

I hope I can help you in the future shortly.


Young... :-)

[leehall2000uk]

Does this mean
Cyan = Green + Blue, no Red
Magenta = Reg + Blue, no Green
Yellow = Red + Green, noBlue
And whatever K is is nothing...
Im confused?

[Paul Ch]

Yes and K is nothing as it is black

Hope this helps

[lorba]

Cyan = 255 - Red
Magenta = 255 - Green
Yellow = 255 - Blue
Black = Min (Red, Green, Blue)

Converting back to displayable colour (unlike Photoshop which after conversion,
still looks very much the same, this part i am not quite sure, rem read from
some where)

new Red = ((Cyan-Black) * 255) / ( 255 - Black )
repeat for the other two channel

hope this helps