[Openicc] new: Proof colour space setting
Kai-Uwe Behrmann
ku.b at gmx.de
Wed May 3 09:35:37 PDT 2006
Ann,
the proofing profile is just a suggestion to show up in the first place.
It can easily been changed in the application itself, like for different
black generation.
regards
Kai-Uwe Behrmann
+ development for color management
+ imaging / panoramas
+ email: ku.b at gmx.de
+ http://www.behrmann.name
Am 03.05.06, 11:44 -0400 schrieb almccart at lexmark.com:
> 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
>
>
>
>
>
> Kai-Uwe Behrmann <ku.b at gmx.de>
> 05/03/2006 05:52 AM
>
>
> To: almccart at lexmark.com
> cc: homann at colormanagement.de, OpenICC Liste <openicc at lists.freedesktop.org>
> Subject: Re: [Openicc] new: Proof colour space setting
>
>
> 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 at gmx.de
> + http://www.behrmann.name
>
>
> Am 02.05.06, 14:36 -0400 schrieb almccart at 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 at colormanagement.de>
> > 05/02/2006 01:41 PM
> > Please respond to homann
> >
> >
> > To: almccart at lexmark.com, OpenICC Liste
> <openicc at 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 at 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 at colormanagement.de>*
> > > Sent by: openicc-bounces at lists.freedesktop.org
> > >
> > > 05/02/2006 07:41 AM
> > > Please respond to homann
> > >
> > >
> > > To: Kai-Uwe Behrmann <ku.b at gmx.de>
> > > cc: OpenICC Liste <openicc at 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 at gmx.de
> > > > + http://www.behrmann.name
> >
>
>
>
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