Re: CGATS text file from a profile
Re: CGATS text file from a profile
- Subject: Re: CGATS text file from a profile
- From: Steve Upton <email@hidden>
- Date: Thu, 03 Mar 2011 10:22:42 -0800
At 11:12 AM -0600 3/3/11, Steve Miller wrote:
>Matt,
>
>Wouldn't editing the paper value in the file "Beta Offset Uncoated 2009.txt" only affect the white point value and not distribute the affects of the changed white throughout the entire color space? This is why I created a profile and edited the white point in the profile. This way the affects of the changed white point are distributed throughout all colors of the color space.
Hi Steve,
A couple of answers:
- Yes, the method you used in ColorThink Pro is a great way to "manufacture" color from a profile. I might have used a full IT8 for the data file but for the use you have in mind in Curve2 a P2P should be sufficient (and a little faster for loading, etc). Just remember to choose abs col for the intent and it'll work great. We've supplied some simple device-space files with ColorThink for this purpose but if you have ProfileMaker you can use any of the included reference files.
- Your question about white point editing is understandable. The reason it works is due to the nature of how ICC profiles are calculated. When profiling software generates the LUTs in a profile it "removes" the paper white from all the colors in the measurements file. As a result each tag (colorimetric, perceptual and saturation) has values that are all relative to "ideal white" (Lab = 100,0,0) and the only remaining evidence of the paper's original white value is in the profile's wtpt tag. This makes "normal" conversions easier as some of the heavy lifting has already been done. When you do an abs col transform (somewhat abnormal I guess), then the CMM reinserts the original white point from the wtpt tag. It's a bit of a messy affair and doesn't always work perfectly but it does leave us with the ability to simply edit a profile's white point in order to change all the colors in abs cols transforms!
Regards,
Steve
________________________________________________________________________
o Steve Upton CHROMiX www.chromix.com
o (hueman) 866.CHROMiX
________________________________________________________________________
--
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden