Am 2018-11-14 um 15:36 schrieb Jan U. Hasecke: > Thanks a lot, Peter. > > Am 14.11.18 um 14:58 schrieb Peter Rolf: >> Hi Jan, >> >> I donno if things have changed (ConTeXt is a fast moving target), so >> take my answers with a grain of salt. >> >> (1) >> AFAIK there is no ACTIVE color management in ConTeXt in the sense that >> there is an automatic color conversion from one profiled(!) colorspace >> into another profiled color space. This means that all given colors >> (objects) have to be in the correct (profiled) color space already! >> >> Objects with embedded color profiles (e.g. a PDF bitmap graphic with icc >> profile) will use those. Objects without a profile will use the >> corresponding "default" color space profiles. These default color space >> profiles can be defined via "profile" in \setupbackend. >> This way every color in the PDF is defined properly. > > This would clarify some of the issues. > > When I define rgb colors AND use not-print-modus I get the right rgb > colors in the pdf. > > When I define cmyk colors AND use print modus I get colors that might be > correct (tested next week) > > But obviously it is not possible to define both color spaces in > \definecolor because I don't get the same colors in the pdf as with the > cmyk-only defined file. > > Maybe I misunderstood this, I've got a hint here, that I could define > rgb and cmyk in the same \definecolor and choose the right color space > in \setupcolors. > > The correct method of defining rgb AND cmyk in the same file would be to > put the definecolor command inside a startstopmode-environment. > > Can someone confirm this? >
Should work (the other part is invisible for ConTeXt). >> >> (2) >> >> I think so. Can't test, because my Windows 10 is beyond repair after >> three "upgrades" and Acrobat is not working properly anymore. >> >> (3) >> >> Judging from the size of the final PDF, the icc profile is not embedded. >> The profiles have to be installed in "the right place" (this includes >> ConTeXt but also the PDF viewer software). >> >> See "ICC profiles" section at >> >> https://wiki.contextgarden.net/PDFX >> > > With --mode=print (which uses the color profiles) the pdf get bigger. >> 10.000 compared to 8.000 without the mode. So I would guess that they > are included. > Mh, the file size of "ISOcoated_v2_300_eci.icc" is around 1.7MB. I highly doubt that ConTeXt can compress it into a 10KB PDF. But I'm not so sure if PDF/X-3 needs embedding (there was an exception). Never used it (only PDF/X-4p) and I can't remember the specifications (all those stuff was added over 8 years ago). I just assume you have installed the icc profiles properly (needs a manual installation!) :D > I hope I get this sorted out, because I want to print a series of > folders and other print products with ConTeXt in the near future. > > juh > >> (5) see (1) and (3) >> >> >> >> Hope this helps, >> >> >> Peter >> >> >> Am 2018-11-14 um 11:39 schrieb Jan U. Hasecke: >>> Hi all, >>> >>> attached you find my colormanagement tests and I need your help to >>> understand and debug the situation. >>> >>> I am testing together with a friend of mine, a professional >>> colormanager, who does not know ConTeXt. >>> >>> >>> There are several files in the archive: >>> >>> The differences in the files are the color definition and the color >>> profile used. >>> >>> - rgb-xxx.tex – colors are defined with RGB values only. >>> >>> - rgb-cmyk-xxx.tex – colors are defined with RGB and CMYK values. >>> >>> The cmyk colors are derived from the rgb values using gimp and the >>> color profiles sRGB/ISOCoated >>> >>> - cmyk-xxx.tex – colors are defined with CMYK values only. >>> >>> The xxx stand for two color profiles: iso-coated and swop. >>> >>> What I see is this: >>> >>> Colors in pdfs are the same no matter what color profile I choose. >>> >>> With rgb values and rgb/cmyk values I get the same colors in pdf (the >>> wrong ones). >>> >>> With cmyk values only I get other colors in pdf. Next week my friend >>> will test if these are the right ones. >>> >>> I have many questions: >>> >>> 1. Is colormanagement working in ConTeXt at all? >>> 2. Is my code correct? >>> 3. Why do pdfs with different color profiles show the same colors? >>> 4. Why does ConTeXt not take the cmyk colors from \definecolor when >>> there are rgb values as well? >>> 5. Where can I define a coresponding rgb profile? In Scribus you have to >>> define two profiles (eg. sRGB and ISOCoated) to make colormanagement work. >>> >>> TIA >>> juh >>> ___________________________________________________________________________________ >>> If your question is of interest to others as well, please add an entry to >>> the Wiki! >>> >>> maillist : ntg-context@ntg.nl / >>> http://www.ntg.nl/mailman/listinfo/ntg-context >>> webpage : http://www.pragma-ade.nl / http://context.aanhet.net >>> archive : https://bitbucket.org/phg/context-mirror/commits/ >>> wiki : http://contextgarden.net >>> ___________________________________________________________________________________ >>> >> >> ___________________________________________________________________________________ >> If your question is of interest to others as well, please add an entry to >> the Wiki! >> >> maillist : ntg-context@ntg.nl / >> http://www.ntg.nl/mailman/listinfo/ntg-context >> webpage : http://www.pragma-ade.nl / http://context.aanhet.net >> archive : https://bitbucket.org/phg/context-mirror/commits/ >> wiki : http://contextgarden.net >> ___________________________________________________________________________________ >> > > ___________________________________________________________________________________ > If your question is of interest to others as well, please add an entry to the > Wiki! > > maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context > webpage : http://www.pragma-ade.nl / http://context.aanhet.net > archive : https://bitbucket.org/phg/context-mirror/commits/ > wiki : http://contextgarden.net > ___________________________________________________________________________________ > ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________
