[External] RGB -> CYMK, with consistent colors
I had a long discussion on this topic with the Springer production group when my book was in production. Statistical Analysis and Data Display: An Intermediate Course with Examples in R, second edition Richard M. Heiberger and Burt Holland. https://www.springer.com/gp/book/9781493921218 As I now understand it, the physical inks used in printing cannot produce the same range of colors as the computer screens. The issue is not the notation, but rather the underlying technology. I chose to let the publisher make the conversion. I looked at the set of pdfs for your book, and to anyone else but you, I think they would look fine in slightly different colors. Rich
On Sun, Nov 29, 2020 at 8:26 AM Derek Jones <gmane at knosof.co.uk> wrote:
All, I used the very useful colorspace package for the plots in my book (pdf available here): http://knosof.co.uk/ESEUR/ The color makes the plots look great, on screen. To get lots printed, the printer requires converting the images to use cmyk (a common requirement for larger printers, I'm told). See page 11 here: https://www.ingramspark.com/hubfs/downloads/file-creation-guide.pdf No problem, the script below uses ghostscript to achieve this: gs -o ESEUR-cmyk.pdf \ -sDEVICE=pdfwrite \ -sProcessColorModel=DeviceCMYK \ -sColorConversionStrategy=CMYK \ -sColorConversionStrategyForImages=CMYK \ ESEUR.pdf the problem is that the converted colors don't look nearly as good. For instance the cyan now looks blue, and prints as pure blue. I can regenerate the images, and explicitly specify cmyk. But using: pdf.options(colormodel="cymk") does not change anything. The colors look remarkably similar to those produced via the ghostview route. I have been looking at color profiles and trying to find a way of modifying an ICC profile (yes, it looks difficult). Does anybody have any ideas for producing cmyk images that have the same (or close enough) look as the RGB?
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