cmyk fractions

[Gethin_Coles@adobeforums.com]

Can anyone tell me why in a CMYK document, when I use the colour picker tool
on a CMYK photo, or sometimes when I shift-drag the colour slider on a CMYK
colour my CMYK values will end up decimalised (like C:21.23% Y:55.12% etc)
There are no RGB images in the document. Is it a problem if they are like
this and is there a way to force illustrator to use whole numbers (or is it
an indicator that something is wrong with the doc)?

Getho

[Jacob_Bugge@adobeforums.com]

Gethin,

As opposed to RGB values, CMYK values come in fractions too. No need to worry. When you define CMYK colours in integers they will remain so, unless you are in RGB mode.

[Scott_Falkner@adobeforums.com]

I believe that colour values in raster images are 8-bits. That gives 256 values from white to black, white to 100% cyan, etc. Illustrator's display is in percentages, so the 8-bit value, converted to a percentage, is not an integer.

[Gethin_Coles@adobeforums.com]

Doh! of course - 256 bits per chanel so 50% is 128/256. And 129/256 is
50.39%. Gotcha!

Geth


<Scott_Falkner@adobeforums.com> wrote in message
news:3bb5577d.1@webx.la2eafNXanI...

> I believe that colour values in raster images are 8-bits. That gives 256

values from white to black, white to 100% cyan, etc. Illustrator's display
is in percentages, so the 8-bit value, converted to a percentage, is not an
integer.