Any experience out there in manipulating lab data for profiles? I’d sometimes like to force the profiling software (i1Profiler) to pick a different TAC than it’s default. I THINK it picks its TAC preferring minimum chroma and I want to allow I little more chroma and pick a lower L*. Or sometimes just force yellow under magenta in rich black of resulting profile. thanks -- Dan Bergstrom | Color Technology and Quality | PRIMARY COLOR ORANGE COUNTY http://www.primarycolor.com | T 949 660 7080 C 949 616 4986
Doesn't I1Profiler give you ample control over TAC? / Roger --- Any experience out there in manipulating lab data for profiles? I’d sometimes like to force the profiling software (i1Profiler) to pick a different TAC than it’s default. I THINK it picks its TAC preferring minimum chroma and I want to allow I little more chroma and pick a lower L*. Or sometimes just force yellow under magenta in rich black of resulting profile. thanks -- Dan Bergstrom | Color Technology and Quality | PRIMARY COLOR ORANGE COUNTY http://www.primarycolor.com | T 949 660 7080 C 949 616 4986 _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx@videotron.ca
i1P proofing profiles are great. My grand format files will sometimes have very thin transitions to rich black. The TAC is unacceptably low. In one instance when I asked for 400 TAC i1P returned a TAC of 141. With same data I performed the following: 320 TAC gives me 320. 340 TAC gives me 340. 350 TAC gives me 141. 360 TAC gives me 141. And finally, 380 TAC gives me 380. Xrite observed this behavior with my data and has submitted, in their words, 'bug' to developer. I have since received no timeline for a fix. And my favorite response to repeated inquiries was, ³use monaco if you have to² I then realized profile L* is always lighter than measured data and now want to pick my own separation by manipulating data. DLP or spot color can achieve the black I want but will not fix neutral rendering of raster data, correct? I can force a better separation by manipulating data but what will I break? :) thanks -- Dan Bergstrom | Color Technology and Quality | PRIMARY COLOR ORANGE COUNTY http://www.primarycolor.com | T 949 660 7080 C 949 616 4986 On 2/27/16, 10:30 AM, "Roger Breton" <graxx@videotron.ca> wrote:
Doesn't I1Profiler give you ample control over TAC?
/ Roger ---
Any experience out there in manipulating lab data for profiles? I¹d sometimes like to force the profiling software (i1Profiler) to pick a different TAC than it¹s default. I THINK it picks its TAC preferring minimum chroma and I want to allow I little more chroma and pick a lower L*. Or sometimes just force yellow under magenta in rich black of resulting profile.
thanks
-- Dan Bergstrom | Color Technology and Quality | PRIMARY COLOR ORANGE COUNTY http://www.primarycolor.com | T 949 660 7080 C 949 616 4986
_______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron. ca
This email sent to graxx@videotron.ca
_______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/danbergstrom%40pri marycolor.com
This email sent to danbergstrom@primarycolor.com
On 27 Feb 2016, at 00:38, Dan Bergstrom <DanBergstrom@primarycolor.com> wrote:
Any experience out there in manipulating lab data for profiles? I’d sometimes like to force the profiling software (i1Profiler) to pick a different TAC than it’s default. I THINK it picks its TAC preferring minimum chroma and I want to allow I little more chroma and pick a lower L*. Or sometimes just force yellow under magenta in rich black of resulting profile.
I posted something a coupIe of months ago about overriding GRACoL profiles default behaviour as it is *impossible* to get rich blue blacks in a conventional ICC workflow nowadays. But you don’t need to manipulate the data. Download ArgyllCMS and make a device link profile using collink and its -G gamut mapping feature. Even if you keep the destination profile’s black curve, if your k max is 100 you’ll find that yellow is completely removed from the darkest blacks and from the blue axis too. And the extra chroma really stands out amongst those drab, ink starved, money saving print jobs that are the norm now :-) -- Martin Orpen Idea Digital Imaging Ltd
Thank you for the tip, Martin! Is it a function of Argyllcms to create this "effect"? Could you briefly walk us through what you do? Best / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Martin Orpen Sent: 29 février 2016 10:13 To: ColorSync <colorsync-users@lists.apple.com> Subject: Re: profile data manipulation On 27 Feb 2016, at 00:38, Dan Bergstrom <DanBergstrom@primarycolor.com> wrote:
Any experience out there in manipulating lab data for profiles? I’d sometimes like to force the profiling software (i1Profiler) to pick a different TAC than it’s default. I THINK it picks its TAC preferring minimum chroma and I want to allow I little more chroma and pick a lower L*. Or sometimes just force yellow under magenta in rich black of resulting profile.
I posted something a coupIe of months ago about overriding GRACoL profiles default behaviour as it is *impossible* to get rich blue blacks in a conventional ICC workflow nowadays. But you don’t need to manipulate the data. Download ArgyllCMS and make a device link profile using collink and its -G gamut mapping feature. Even if you keep the destination profile’s black curve, if your k max is 100 you’ll find that yellow is completely removed from the darkest blacks and from the blue axis too. And the extra chroma really stands out amongst those drab, ink starved, money saving print jobs that are the norm now :-) -- Martin Orpen Idea Digital Imaging Ltd
On 29 Feb 2016, at 15:49, Roger Breton <graxx@videotron.ca> wrote:
Is it a function of Argyllcms to create this "effect”?
Yes, because it doesn’t do black width and GCR :-)
Could you briefly walk us through what you do?
Sure. Here’s the lazy version for Terminalphobics who would prefer to drag and drop and not have to properly install ArgyllCMS: 1. Open the Terminal and type “cd” (not the quotes) and a space. Drag the bin folder from your downloaded version of Argyll on the Terminal window and hit return. 2. Type ./collink -v -ke -G -ip Add a space and then drag & drop the AdobeRGB1998 profile on the Terminal window followed by the GRACoL2006_Coated1v2 profile and then type the name that you’d like to call your profile e.g. aRGB_2_GRACoL2006.icc Hit return and collink will build your gamut mapped device link profile and save it into the bin folder. 3. Make a test image — Argyll’s default is good for this test — it will also be saved into the bin folder: ./timage -v -r1200 -s -x myTestImage.tif 4. Convert the test image using your new device link: ./cctiff -v [drag & drop your device link profile] [drag & drop the test image] myCMYK.tif [The converted image is untagged (you can easily tag the images in Argyll, but I wanted to keep the above as stripped down and as simple as possible.] Open the converted image and look at the yellow channel in the right hexagon :-) -- Martin Orpen Idea Digital Imaging Ltd
Roger Breton wrote:
Is it a function of Argyllcms to create this "effect"?
Hi Roger, there is nothing user accessible to change the choice of black point in CMYK profile creation (no-one has ever asked me for such a thing). There are a couple of programmatic choices, my original one being to pick a black that had the same hue as K only, but at some prompting by users, I switched to picking a black that has a consistent hue with white. In either case, there can be a slight compromising of the the hue direction (0.5 DE) against minimum L*, and those values can be changed programmatically. I don't seem to have got Martin Orpen's post you attached. Using collink -G creates a device link from the output profiles A2B table, so it re-generates the profile inversion and black generation. There is a similar (but much less sophisticated and less debugged program) <http://www.argyllcms.com/doc/revfix.html> that re-generates a an ICC profiles B2A colorimetric table, allowing re-setting of the black generation and ink limits. Graeme Gill.
participants (4)
-
Dan Bergstrom
-
Graeme Gill
-
Martin Orpen
-
Roger Breton