Re: Uniform Perceptual Lab space v2
Re: Uniform Perceptual Lab space v2
- Subject: Re: Uniform Perceptual Lab space v2
- From: Roger Breton <email@hidden>
- Date: Tue, 24 Feb 2004 23:07:13 -0500
>
I discovered an adaptation of CIE Lab color space some time ago on Bruce
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Lindbloom's website. The discussion on its use describes the problems
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that I have been having with printer output. Saturated blues go purple,
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saturated reds go orange and images with little more than shades of
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yellow are under saturated.
I'd be interested to learn more about your experience with this phenomenon?
Care to elaborate some more, quote some figures?
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According to Lindbloom's Munsell Display
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Calculator, all of these problems are due to non-uniformities in the CIE
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Lab color space, which are made manifest during gamut correction. He
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created a Uniform Lab space which straightened the constant hue radials
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and makes spheres out of constant chroma rings. If I could just use it...
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I have been trying to find a way of applying this UPLab space after
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Device>Lab (A2B*), so that the gamut corrections will be uniform when
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the Lab>Device (B2A*) conversion occurs. Clearly this is beyond my
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abilities, but I was wondering if anyone knows of a tool to manipulate
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profiles in this way. Could it be as simple as adding another tag, such
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as an B2B and copying the text from the Lindbloom UPLab profile to the
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output profile -- see how much I don't know.
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Lindbloom suggests that only developers could use his Lab-Lab profile. I
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believe him because I can't find anything, outside of the OS 10
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ColorSync Utility, that will open his L-L profile.
Didn't ColorBlind Edit used to be able to load Abstract (Lab to Lab)
profiles? I seem to remember that the user could save all edits in such an
way for later recalling.
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Is any developer considering making use of this Lab-Lab conversion
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process? If they did, they would solve most of the problems which force
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me to proof and reproof, over and over, depending on how many of the
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issue noted above the particular image contains.
But are you getting improved results each time you reproof over and over?
>
Tim Vitale
Regards,
Roger Breton | Laval, Canada | email@hidden
http://pages.infinit.net/graxx
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