Kai-Uwe, Any 'final output condition' [such as SWOP] profile can be used in a color managed color conversion for proofing.   For example, perhaps you are suggesting that everyone agree on using a single 'SWOP' profile in the retargeting conversion when proofing for SWOP?  I think that is not a workable idea.  There are valid reasons to want different behaviors in making the first conversion from three component space to 4 component space - e.g., black component. Best regards, Ann McCarthy Lexmark CPD Imaging Systems Engineering ICC Workflow WG Chair <table width=100%> <tr valign=top> <td> <td>Kai-Uwe Behrmann <ku.b@gmx.de> 05/03/2006 05:52 AM <td>                To:        almccart@lexmark.com         cc:        homann@colormanagement.de, OpenICC Liste <openicc@lists.freedesktop.org>         Subject:        Re: [Openicc] new: Proof colour space setting</table> Hello Ann and all, the idea of mine was to define a system wide proofing colour space, a profile, which can be used by applications as a predefined and optional activated profile for poofing on screen and print out. The proofing profile settings set and activate the simulation of a film stock or a intended printing condition (SWOP/ISOcoated). Your idea is more about a single colour space, like PhotoGamut(?), in differenence to a general system setting. Sorry if my head line was missleading you. I changed the head therefore. Of course feel free to continue this interessting toppic. For the "proofing profile setting", hope this makes a difference now, I decided to add it to the Oyranos configuration settings. kind regards Kai-Uwe Behrmann                                + development for color management                                + imaging / panoramas                                + email: ku.b@gmx.de                                + http://www.behrmann.name Am 02.05.06, 14:36 -0400 schrieb almccart@lexmark.com: > Hi Jan-Peter and all, > > I would agree that it needs to be a free choosable color space that is > independent of > scanner, camera, monitor, types of RGB spaces and that is also independent > of any > particular CMYK.  Note that Adobe RGB is a monitor type of RGB even though > it is > wide gamut. > > Yes - I was thinking that a proofing color space would be an intermediate > between the > source color spaces [e.g., Adobe RGB, camera Raw RGB] and particular print > related > output spaces.  One question is how constrained should the gamut be? > Should it be > limited to a SWOP-like gamut? Or be like the ISO reference gamut - which > is a bit larger. > Another way of thinking about it is -- Would you want a proofing color > space to contain > the Pantone colors? Or to be limited to a subset of Pantone colors as many > real print > systems are? > > I think you got the idea I was putting forth.  My question is - is that > what you and Kai-Uwe > had in mind? > > Best regards, > Ann McCarthy > Lexmark CPD > Imaging Systems Engineering > ICC Workflow WG Chair > > > > > > Jan-Peter Homann <homann@colormanagement.de> > 05/02/2006 01:41 PM > Please respond to homann > >   >         To:     almccart@lexmark.com, OpenICC Liste <openicc@lists.freedesktop.org> >         cc: >         Subject:        Re: [Openicc] new: Proof colour space > > > Hello Ann, and all, > Nice to hear, that leading ICC members are reading and posting to the > openICC list :-) > > I think, your answer is two steps ahead, of the mail of Kai-Uwe. > As I understand him, he want the possibility of a free choosable > proofing colorspace independent from the RGB- or CMYK-workingspace in > ICC aware open source applications. > > As I understand your concept of an "proofing colorspace" as an > intermediate colorspace between widegamut colorspaces like > camera-profiles on RAW data or AdobeRGB and printoutput. > > Finetuning of colors and saturation is done in the "proofing > colorspace", if the work is done, gamutmapping from "proofing > colorspace" to print output colorspace needs and can be done either with > relatice colorinteric and blackpoint-comepnesation or with ICCv4 > perceptual gamutmapping, if the gamut of the "proofing colorspace" is > similar of a better "reference medium gamut" for ICCv4 profiles. > > Do I understand your intentions correct ? > > :-) Jan-Peter > > almccart@lexmark.com wrote: > > > > Hello Jan-Peter and all, > > > > So -- if we were to define a 'proofing colorspace' what would the > > requirements be? > > For example: > > 1. RGB encoding > > 2. Encompassing and similar in shape to the ISO printing gamut defined > > in ISO 12640-3 Annex B > > 3. Not significantly larger than the ISO printing gamut defined in ISO > > 12640-3 Annex B > > 4. Unambiguously defined transformations to/from CIE XYZ > > 5. Primaries placed so that if the file is incorrectly assumed to be > > sRGB, severe hue shifts do not occur. > > 6. Primaries placed so that HVS response to tone and hue adjustments are > > > reasonably homogeneous > > throughout the space [i.e., perceptual isometry]. > > 7. Adapted white point, color space white point and black point > > chromaticity = D50 > > 8. Print-referred image state > > 9. Adapted white point and color space white point luminance: 160 cd/m^2 > > >   [=ICC PCS] > > 10. Image surround - 20% of adapted white point > > ...? > > > > Does this represent a good initial list of attributes? > > Is there an existing public domain RGB that meets these criteria? > > > > Best regards, > > Ann McCarthy > > Lexmark CPD > > Imaging Systems Engineering > > ICC Workflow WG Chair > > > > > > > > > >                *Jan-Peter Homann <homann@colormanagement.de>* > > Sent by: openicc-bounces@lists.freedesktop.org > > > > 05/02/2006 07:41 AM > > Please respond to homann > > > > > >         To:        Kai-Uwe Behrmann <ku.b@gmx.de> > >         cc:        OpenICC Liste <openicc@lists.freedesktop.org> > >         Subject:        Re: [Openicc] new: Proof colour space > > > > > > > > > > Hello list, > > A proofing colorspace would be very helpful. > > I know  several photostudios, which are dealing with agencies, prepress > > bureaus and print shops. > > > > They are working in RGB and deliver RGB and CMYK-Files (ISOcoated) to > > their clients. > > > > Before they are converting to CMYK (ISOcoated) with relative > > colorimetric and blackpoint compensation, they do a proof and optimize > > the RGB-file, if colorclipping of saturated colors are occuring. > > > > The goal is to build an archive of RGB-files, where all RGB-files can be > > converted relative colorimetric with blackpoint compensation to the main > >   destination colorspace, without the need to make image by image > > analysis , which rendering intent fits best. > > > > Most uzsers I know prefer to have a special menue for softproofing, > > instead of doing it in the colorsetting file. > > > > Very helpful is also, if the softproof menue is synchronized with the > > menue "convert to profile" > > > > If the softproof is OK, the file can be converted to the destination > > colorspace with one mouseclick. > > > > :-) Jan-Peter > > > > > > Kai-Uwe Behrmann wrote: > >  > Hello list, > >  > > >  > what would you think about a dedicated proof colour space? > >  > > >  > The current situation in CinePaint is: we have RGB/Cmyk image data > > and can > >  > proof them to whatever colour space on screen. If someone wants to > >  > simulate an special output device like a film stock or a print media, > it > >  > seems there is no sense by sticking to the editing colour spaces > >  > (RGB/Cmyk). It is not clear if the user wants a RGB or Cmyk colour > space > >  > to proof against. > >  > > >  > It could as well mean the proofing options should become a separate > >  > advanced configuration group. > >  > > >  > Whats the opinion on the list about this matter? > >  > > >  > regards > >  > Kai-Uwe Behrmann > >  >                                 + development for color management > >  >                                 + imaging / panoramas > >  >                                 + email: ku.b@gmx.de > >  >                                 + http://www.behrmann.name >