[cairo] Subtractive API, part 0

[Chris Murphy]

On Jan 28, 2010, at 9:03 AM, ecir hana wrote:

> On Thu, Jan 28, 2010 at 5:00 PM, ecir hana <ecir.hana at gmail.com> wrote:
>> because cmyk (0, 0, 0, 0) is most probably rgb(0, 0, 0)
> 
> Sorry, I meant:
> because cmyk (0, 0, 1, 1) is most probably rgb(0, 0, 0)

Definitely not. It's a yellow black, and black only is not nearly as dark as RGB black. If I define CMYK 0,0,1,1 with SWOP 2006 Coated 5 I get:

sRGB = 43, 42, 25 (8bpc encoding 0-255)

If I define the same values with a profile for an Epson 7900 on their proofing paper driven by a RIP:

sRGB = 52, 49, 31



Chris Murphy
Color Remedies (TM)
New York, NY
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Co-author "Real World Color Management, 2nd Ed"