<br><br><div class="gmail_quote">On Tue, Dec 20, 2011 at 12:19 PM, john Culleton <span dir="ltr"><<a href="mailto:John@wexfordpress.com">John@wexfordpress.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="HOEnZb"><div class="h5">On Tue, 20 Dec 2011 12:06:11 -0600<br>
Patrick Noffke <<a href="mailto:patrick.noffke@gmail.com">patrick.noffke@gmail.com</a>> wrote:<br>
<br>> ><br>
> Because I want to experiment with different ICC profiles for the same<br>
> sRGB colors (which will include images in addition to these<br>
> rectangles). I want the profile to define the conversion to CMYK for<br>
> all sRGB colors.<br>
><br>
<br>
</div></div>I obtained a profile that seems to do the conversion OK. Why do<br>
you need to create your own? I use the following profile<br>
which also limits the ink density to 240%:<br>
SWOPcoated5_240.icc<br>
Available here:<br>
<a href="http://wexfordpress.com/tex/SWOPcoated5_240.icc" target="_blank">http://wexfordpress.com/tex/SWOPcoated5_240.icc</a><br>
<br></blockquote><div><br></div><div>That doesn't change the problem. Scribus is still converting colors with R=G=B to black only, and nearby colors (e.g. R=0, G=1, B=0) to 4-color CMYK values. With real inks, even with a 240 max TAC, there will be a big color difference in these CMYK values.</div>
<div><br></div><div>Here is the portion of the (uncompressed) PDF that results using the SWOPcoated5_240 profile:</div><div><br></div><div><div>q</div><div> 1 0 0 1 0 0 cm</div><div> q</div><div> 0 0 0 0.25098 k 0 0 0 1 K 1 w [] 0 d 0 J 0 j 1 0 0 1 40.83465 751.49291 cm 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h f*</div>
<div> 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h S</div><div> Q</div><div> q</div><div> 0 0 0 0.50196 k 0 0 0 1 K 1 w [] 0 d 0 J 0 j 1 0 0 1 60 751.49291 cm 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h f*</div>
<div> 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h S</div><div> Q</div><div> q</div><div> 0 0 0 0.74902 k 0 0 0 1 K 1 w [] 0 d 0 J 0 j 1 0 0 1 78.84252 751.49291 cm 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h f*</div>
<div> 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h S</div><div> Q</div><div> q</div><div> 0 0 0 1 k 0 0 0 1 K 1 w [] 0 d 0 J 0 j 1 0 0 1 97.68504 751.49291 cm 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h f*</div>
<div> 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h S</div><div> Q</div><div> q</div><div> 0.43529 0.4 0.51373 0.99608 k 0 0 0 1 K 1 w [] 0 d 0 J 0 j 1 0 0 1 116.52756 751.49291 cm 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h f*</div>
<div> 0 0 m 17.0079 0 l 17.0079 -17.0079 l 0 -17.0079 l 0 0 l h S</div><div> Q</div><div>Q</div></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Any conversion from RGB to CMYK will involve some shift in<br>
colors. Not all RGB colors can be expressed in CMYK.<br>
But you knew that already, right?<br>
<span class="HOEnZb"><font color="#888888"><br></font></span></blockquote><div><br></div><div>Yes, I realize that. I want to convert my document to CMYK using profiles with the same gamut, but other differences that I am enforcing (e.g. different GCR).</div>
<div><br></div><div>You ask why. I design color measurement devices for offset and newspaper printing presses. Lately, I'm researching how to measure TVI from an image. I need to enforce known TVI differences in the color separations from a document I create. I can do this with Matlab using (CMYK) TIFFs, but it is tedious to design my document that way, so I wanted to do it with Scribus. (I can also enforce TVI differences by modifying the ICC profile's output curves.)</div>
<div><br></div><div>Thanks,</div><div>Pat</div><div><br></div></div>