Thread: [Lcms-user] Converting from LAB to RGB
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From: Alexander W. R. <a....@gm...> - 2013-12-12 02:59:00
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I'm trying to convert PANTONE colors to RGB. I have decoded the Adobe ASE Pantone swatch, and the output colors are in LAB format. I'm trying to convert to RGB using LittleCMS's transicc tool using the following command: echo 0.5019608 0 -2 | transicc -i *Lab -o sRGB_IEC61966-2-1_black_scaled.icc -t 1 -b output: 0.1012 1.9455 6.7276 In Illustrator this color is computed as: 119 119 121 Where am I going wrong with the input params? Thanks in advance for the help -- Alexander W. Rolek |
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From: Marti M. <mar...@li...> - 2013-12-12 08:54:07
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Hello, 0.5019608 0 -2 If this is Lab, then it is an extraordinarily dark black. No printer that I know can render such density, chances are that the decoding is not proper and the Lab value is wrong. When you fix that, you also need to use absolute colorimetric intent (yes, that is one of those rare cases where abs.col. is needed). Remove black point compensation, it does not work in abs. col. Please also note PANTONE does not distribute the Lab values, only the CMYK and in this case, the values are for the intended device/standard only . Another option would be to locate a named color profile and use the PANTONE name directly, but those color profiles are not free and most of times difficult to find. Good luck Marti El 12/12/2013 3:58, Alexander W. Rolek escribió: > I'm trying to convert PANTONE colors to RGB. I have decoded the Adobe > ASE Pantone swatch, and the output colors are in LAB format. I'm > trying to convert to RGB using LittleCMS's transicc tool using the > following command: > > echo 0.5019608 0 -2 | transicc -i *Lab -o > sRGB_IEC61966-2-1_black_scaled.icc -t 1 -b > > output: 0.1012 1.9455 6.7276 > > In Illustrator this color is computed as: 119 119 121 > > Where am I going wrong with the input params? > > Thanks in advance for the help > > -- > Alexander W. Rolek > > > > ------------------------------------------------------------------------------ > Rapidly troubleshoot problems before they affect your business. Most IT > organizations don't have a clear picture of how application performance > affects their revenue. With AppDynamics, you get 100% visibility into your > Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! > http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk > > > _______________________________________________ > Lcms-user mailing list > Lcm...@li... > https://lists.sourceforge.net/lists/listinfo/lcms-user |
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From: Richard H. <hug...@gm...> - 2013-12-12 09:07:00
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On 12 December 2013 08:54, Marti Maria <mar...@li...> wrote: > Another option would be to locate a named color profile and use the PANTONE > name directly, but those color profiles are not free and most of times > difficult to find. If you do stumble on the .icc named color icc files from Pantone, the cd-iccdump utility dumps the actual Lab values to the screen, tab separated. Richard. |
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From: Alexander W. R. <a....@gm...> - 2013-12-12 19:21:54
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Thanks for the quick response. I found the issue. It appears the first
value that the ASE color entry is returning is between 0 and 1, rather than
0 and 100. I'm decoding the PANTONE ASE swatches from Illustrator, and I'm
getting LAB based output. For example:
{
"NameLen": 22,
"Name": "PANTONE Cool Gray 9 C",
"Model": "LAB",
"Values": [
0.5019608,
0,
-2
],
"Type": "Spot"
},
New command line:
echo 50.19608 0 -2 | transicc -i *Lab -o sRGB_IEC61966-2-1_black_scaled.icc
-t 3
I removed black point compensation and changed the rendering intent to
absolute colorimetric. New output:
R=118.1790 G=119.4981 B=122.7821
In Illustrator, the values for this color entry are:
R=119 G=119 B=121
Any idea what I can do to fine tune the transicc output to match
Illustrator?
Thanks for the help.
Alex
On Thu, Dec 12, 2013 at 1:06 AM, Richard Hughes <hug...@gm...> wrote:
> On 12 December 2013 08:54, Marti Maria <mar...@li...> wrote:
> > Another option would be to locate a named color profile and use the
> PANTONE
> > name directly, but those color profiles are not free and most of times
> > difficult to find.
>
> If you do stumble on the .icc named color icc files from Pantone, the
> cd-iccdump utility dumps the actual Lab values to the screen, tab
> separated.
>
> Richard.
>
--
Alexander W. Rolek
303-829-9989
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From: <jc...@gm...> - 2013-12-14 10:09:26
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On 12 December 2013 19:21, Alexander W. Rolek <a....@gm...> wrote: > absolute colorimetric. New output: > > R=118.1790 G=119.4981 B=122.7821 > > In Illustrator, the values for this color entry are: > R=119 G=119 B=121 > > Any idea what I can do to fine tune the transicc output to match > Illustrator? Could it be partly a D65 / D50 thing? sRGB is supposed to be D65 but I bet that's D50 LAB in illustrator. If I take your 50.196,0,-2 coordinate to XYZ, then adjust the white point, then go to sRGB I get 118, 120, 122, which is a bit closer. John |
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From: <mar...@li...> - 2013-12-14 14:30:08
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Hello, > In Illustrator, the values for this color entry are: > R=119 G=119 B=121 Photoshop CS6 gives me (118, 119, 123) for Cool Gray 9C, which is exactly what you get from lcms after rounding. Bruce Lindbloom site http://www.brucelindbloom.com/ColorCalculator.html also reports same ... I wonder why Illustrator is giving you such values. Regards Marti Quoting "Alexander W. Rolek" <a....@gm...>: > Thanks for the quick response. I found the issue. It appears the first > value that the ASE color entry is returning is between 0 and 1, rather than > 0 and 100. I'm decoding the PANTONE ASE swatches from Illustrator, and I'm > getting LAB based output. For example: > { > "NameLen": 22, > "Name": "PANTONE Cool Gray 9 C", > "Model": "LAB", > "Values": [ > 0.5019608, > 0, > -2 > ], > "Type": "Spot" > }, > > New command line: > > echo 50.19608 0 -2 | transicc -i *Lab -o sRGB_IEC61966-2-1_black_scaled.icc > -t 3 > > I removed black point compensation and changed the rendering intent to > absolute colorimetric. New output: > > R=118.1790 G=119.4981 B=122.7821 > > In Illustrator, the values for this color entry are: > R=119 G=119 B=121 > > Any idea what I can do to fine tune the transicc output to match > Illustrator? > > Thanks for the help. > > Alex > > > > On Thu, Dec 12, 2013 at 1:06 AM, Richard Hughes <hug...@gm...> wrote: > >> On 12 December 2013 08:54, Marti Maria <mar...@li...> wrote: >> > Another option would be to locate a named color profile and use the >> PANTONE >> > name directly, but those color profiles are not free and most of times >> > difficult to find. >> >> If you do stumble on the .icc named color icc files from Pantone, the >> cd-iccdump utility dumps the actual Lab values to the screen, tab >> separated. >> >> Richard. >> > > > > -- > Alexander W. Rolek > 303-829-9989 |
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From: Alexander W. R. <a....@gm...> - 2013-12-17 18:20:37
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Marti - Very interesting. I just cross referenced Adobe Photoshop CS6 and Adobe Illustrator CC, and they are different. Baffles me that two Adobe products will have different color conversion values for the same Pantone Color... Alex On Sat, Dec 14, 2013 at 6:29 AM, <mar...@li...> wrote: > > Hello, > > > In Illustrator, the values for this color entry are: >> R=119 G=119 B=121 >> > > Photoshop CS6 gives me (118, 119, 123) for Cool Gray 9C, which > is exactly what you get from lcms after rounding. Bruce Lindbloom > site http://www.brucelindbloom.com/ColorCalculator.html > also reports same ... I wonder why Illustrator is giving you such > values. > > Regards > Marti > > > Quoting "Alexander W. Rolek" <a....@gm...>: > > Thanks for the quick response. I found the issue. It appears the first >> value that the ASE color entry is returning is between 0 and 1, rather >> than >> 0 and 100. I'm decoding the PANTONE ASE swatches from Illustrator, and I'm >> getting LAB based output. For example: >> { >> "NameLen": 22, >> "Name": "PANTONE Cool Gray 9 C", >> "Model": "LAB", >> "Values": [ >> 0.5019608, >> 0, >> -2 >> ], >> "Type": "Spot" >> }, >> >> New command line: >> >> echo 50.19608 0 -2 | transicc -i *Lab -o sRGB_IEC61966-2-1_black_ >> scaled.icc >> -t 3 >> >> I removed black point compensation and changed the rendering intent to >> absolute colorimetric. New output: >> >> R=118.1790 G=119.4981 B=122.7821 >> >> In Illustrator, the values for this color entry are: >> R=119 G=119 B=121 >> >> Any idea what I can do to fine tune the transicc output to match >> Illustrator? >> >> Thanks for the help. >> >> Alex >> >> >> >> On Thu, Dec 12, 2013 at 1:06 AM, Richard Hughes <hug...@gm...> >> wrote: >> >> On 12 December 2013 08:54, Marti Maria <mar...@li...> >>> wrote: >>> > Another option would be to locate a named color profile and use the >>> PANTONE >>> > name directly, but those color profiles are not free and most of times >>> > difficult to find. >>> >>> If you do stumble on the .icc named color icc files from Pantone, the >>> cd-iccdump utility dumps the actual Lab values to the screen, tab >>> separated. >>> >>> Richard. >>> >>> >> >> >> -- >> Alexander W. Rolek >> 303-829-9989 >> > > > -- Alexander W. Rolek 303-829-9989 |
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From: Martin F. <mf...@gm...> - 2013-12-17 20:28:04
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Could it be that you have different working color spaces set in them? Martin On 17. 12. 2013 19:20, Alexander W. Rolek wrote: > Marti - > > Very interesting. I just cross referenced Adobe Photoshop CS6 and Adobe > Illustrator CC, and they are different. Baffles me that two Adobe > products will have different color conversion values for the same > Pantone Color... > > Alex > > > On Sat, Dec 14, 2013 at 6:29 AM, <mar...@li... > <mailto:mar...@li...>> wrote: > > > Hello, > > > In Illustrator, the values for this color entry are: > R=119 G=119 B=121 > > > Photoshop CS6 gives me (118, 119, 123) for Cool Gray 9C, which > is exactly what you get from lcms after rounding. Bruce Lindbloom > site http://www.brucelindbloom.com/__ColorCalculator.html > <http://www.brucelindbloom.com/ColorCalculator.html> > also reports same ... I wonder why Illustrator is giving you such > values. > > Regards > Marti > > > Quoting "Alexander W. Rolek" <a....@gm... > <mailto:a....@gm...>>: > > Thanks for the quick response. I found the issue. It appears the > first > value that the ASE color entry is returning is between 0 and 1, > rather than > 0 and 100. I'm decoding the PANTONE ASE swatches from > Illustrator, and I'm > getting LAB based output. For example: > { > "NameLen": 22, > "Name": "PANTONE Cool Gray 9 C", > "Model": "LAB", > "Values": [ > 0.5019608, > 0, > -2 > ], > "Type": "Spot" > }, > > New command line: > > echo 50.19608 0 -2 | transicc -i *Lab -o > sRGB_IEC61966-2-1_black___scaled.icc > -t 3 > > I removed black point compensation and changed the rendering > intent to > absolute colorimetric. New output: > > R=118.1790 G=119.4981 B=122.7821 > > In Illustrator, the values for this color entry are: > R=119 G=119 B=121 > > Any idea what I can do to fine tune the transicc output to match > Illustrator? > > Thanks for the help. > > Alex > > > > On Thu, Dec 12, 2013 at 1:06 AM, Richard Hughes > <hug...@gm... <mailto:hug...@gm...>> wrote: > > On 12 December 2013 08:54, Marti Maria > <mar...@li... > <mailto:mar...@li...>> wrote: > > Another option would be to locate a named color profile > and use the > PANTONE > > name directly, but those color profiles are not free and > most of times > > difficult to find. > > If you do stumble on the .icc named color icc files from > Pantone, the > cd-iccdump utility dumps the actual Lab values to the > screen, tab > separated. > > Richard. > > > > > -- > Alexander W. Rolek > 303-829-9989 <tel:303-829-9989> > > > > > > > -- > Alexander W. Rolek > 303-829-9989 > > > ------------------------------------------------------------------------------ > Rapidly troubleshoot problems before they affect your business. Most IT > organizations don't have a clear picture of how application performance > affects their revenue. With AppDynamics, you get 100% visibility into your > Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! > http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk > > > > _______________________________________________ > Lcms-user mailing list > Lcm...@li... > https://lists.sourceforge.net/lists/listinfo/lcms-user > |
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From: Graeme G. <gr...@ar...> - 2013-12-13 00:20:36
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Marti Maria wrote: > Please also note PANTONE does not distribute the Lab values, only the CMYK and in this > case, the values are for the intended device/standard only . Actually you can export Lab .cxf files from their Pantone Color Manager application. [ It's sad that there is no spectral information exported though - their older product ColorDrive exported spectral as well. ] Graeme Gill. |
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From: <mar...@li...> - 2013-12-13 09:35:02
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Quoting Graeme Gill <gr...@ar...>: > Actually you can export Lab .cxf files from their Pantone Color > Manager application. Sure, and there are many other sources... the issue is with the license, AFAIK PANTONE sells those lists. See for example this answer related with GOE colors: http://pantone.custhelp.com/app/answers/detail/a_id/1679/kw/lab%20values/session/L3RpbWUvMTM4NjkyNjk1MC9zaWQvNEF6cWtJSGw%3D Regards Marti |
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From: Graeme G. <gr...@ar...> - 2013-12-14 07:00:12
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mar...@li... wrote: > Sure, and there are many other sources... the issue is with > the license, AFAIK PANTONE sells those lists. > See for example this answer related with GOE colors: Right, but buying Pantone Color Manager gives you a legally purchased copy of the Lab values. If you couldn't use them, what would be the point of buying it ? Graeme Gill. |
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From: Martin F. <mf...@gm...> - 2013-12-19 09:57:36
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If it is not the working color space, then it could be a different chromatic adaptation method. try the Bruce Lindbloom's online calculator here http://www.brucelindbloom.com/ At the bottom, there is an "Adaptation" field, try different values there. Martin On 17.12.2013 22:01, Alexander W. Rolek wrote: > Thanks for the quick response. Here is a compiled group of screen shots > between Illustrator and Photoshop's color settings and the color values > in the color picker. I have used PANTONE Cool Gray 9 C for both > programs. I'm using the same color profiles in both of them, but the > color values are different. It's so strange. I would love to figure out > where the discrepancy is. Inline image 1 > > > On Tue, Dec 17, 2013 at 12:28 PM, Martin Florek <mf...@gm... > <mailto:mf...@gm...>> wrote: > > Could it be that you have different working color spaces set in them? > > Martin > > > > On 17. 12. 2013 19:20, Alexander W. Rolek wrote: > > Marti - > > Very interesting. I just cross referenced Adobe Photoshop CS6 > and Adobe > Illustrator CC, and they are different. Baffles me that two Adobe > products will have different color conversion values for the same > Pantone Color... > > Alex > > > On Sat, Dec 14, 2013 at 6:29 AM, <mar...@li... > <mailto:mar...@li...> > <mailto:marti.maria@littlecms.__com > <mailto:mar...@li...>>> wrote: > > > Hello, > > > In Illustrator, the values for this color entry are: > R=119 G=119 B=121 > > > Photoshop CS6 gives me (118, 119, 123) for Cool Gray 9C, which > is exactly what you get from lcms after rounding. Bruce > Lindbloom > site http://www.brucelindbloom.com/____ColorCalculator.html > <http://www.brucelindbloom.com/__ColorCalculator.html> > > <http://www.brucelindbloom.__com/ColorCalculator.html > <http://www.brucelindbloom.com/ColorCalculator.html>> > also reports same ... I wonder why Illustrator is giving > you such > values. > > Regards > Marti > > > Quoting "Alexander W. Rolek" <a....@gm... > <mailto:a....@gm...> > <mailto:a....@gm... <mailto:a....@gm...>>>: > > > Thanks for the quick response. I found the issue. It > appears the > first > value that the ASE color entry is returning is between > 0 and 1, > rather than > 0 and 100. I'm decoding the PANTONE ASE swatches from > Illustrator, and I'm > getting LAB based output. For example: > { > "NameLen": 22, > "Name": "PANTONE Cool Gray 9 C", > "Model": "LAB", > "Values": [ > 0.5019608, > 0, > -2 > ], > "Type": "Spot" > }, > > New command line: > > echo 50.19608 0 -2 | transicc -i *Lab -o > sRGB_IEC61966-2-1_black_____scaled.icc > > -t 3 > > I removed black point compensation and changed the > rendering > intent to > absolute colorimetric. New output: > > R=118.1790 G=119.4981 B=122.7821 > > In Illustrator, the values for this color entry are: > R=119 G=119 B=121 > > Any idea what I can do to fine tune the transicc output > to match > Illustrator? > > Thanks for the help. > > Alex > > > > On Thu, Dec 12, 2013 at 1:06 AM, Richard Hughes > <hug...@gm... <mailto:hug...@gm...> > <mailto:hug...@gm... <mailto:hug...@gm...>>> wrote: > > On 12 December 2013 08:54, Marti Maria > <mar...@li... > <mailto:mar...@li...> > <mailto:marti.maria@littlecms.__com > <mailto:mar...@li...>>> wrote: > > Another option would be to locate a named color > profile > and use the > PANTONE > > name directly, but those color profiles are not > free and > most of times > > difficult to find. > > If you do stumble on the .icc named color icc files > from > Pantone, the > cd-iccdump utility dumps the actual Lab values to the > screen, tab > separated. > > Richard. > > > > > -- > Alexander W. Rolek > 303-829-9989 <tel:303-829-9989> <tel:303-829-9989 > <tel:303-829-9989>> > > > > > > > > -- > Alexander W. Rolek > 303-829-9989 <tel:303-829-9989> > > > ------------------------------__------------------------------__------------------ > Rapidly troubleshoot problems before they affect your business. > Most IT > organizations don't have a clear picture of how application > performance > affects their revenue. With AppDynamics, you get 100% visibility > into your > Java,.NET, & PHP application. Start your 15-day FREE TRIAL of > AppDynamics Pro! > http://pubads.g.doubleclick.__net/gampad/clk?id=84349831&iu=__/4140/ostg.clktrk > <http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk> > > > > _________________________________________________ > Lcms-user mailing list > Lcm...@li....__net > <mailto:Lcm...@li...> > https://lists.sourceforge.net/__lists/listinfo/lcms-user > <https://lists.sourceforge.net/lists/listinfo/lcms-user> > > > > > -- > Alexander W. Rolek > 303-829-9989 |
