Learn how easy it is to sync an existing GitHub or Google Code repo to a SourceForge project!

## lcms-user

 [Lcms-user] Conversion Lab to RGB issue From: Robert V Canning - 2009-10-02 18:02:31 Attachments: Message as HTML ```I am trying to verify that I am doing L*a*b* conversion to sRGB correctly. The issue I find is that when I do the transformation the results are always the same for each colorspace. I am trying to compare the converted Lab in D50 2 degrees to sRGB to that of Labs in D65 2 degrees to sRGB. I have taken the following steps: 1) I get a White Point for D50 2 degrees using {96.422, 100.0, 82.521} xyY = {0.3456, 0.3585, 100.0} 2) I get a White Point for D65 2 degrees using {95.047, 100.0, 108.883} xyY = { 0.3127, 0.329, 100.0 } 3) Create input profiles using white points above (cmsCreateLabProfile) 4) Create output profile using cmsCreate_sRGBProfile 5) Create transforms one for Lab D50 to sRGB and other for Lab D65 to sRGB 6) Call cmsDoTransform - 7) Also use cmsLab2XYZ to view the XYZs L*a*b* 50, 20, 30 D50 2 deg XYZ = 21.7748, 18.4187, 6.06875 D50 2 deg RGB = 161, 105, 69 D65 2 deg XYZ = 21.46429, 18.41865, 8.007 D65 2 deg RGB = 161, 105, 69 Each set of Labs I use produces the same RGBs for both D50 and D65 which is not what I would think it would do. I have compared my results with the BruceLindbloom.com site and the values for D50s are different than D65s. The XYZs are different for the two and agree with the Lindbloom calculation. Am I missing a step. It seems to me that the conversion always produces D50 2 degree results. Thanks, Bob This communication is for use by the intended recipient and contains information that may be Privileged, confidential or copyrighted under applicable law. If you are not the intended recipient, you are hereby formally notified that any use, copying or distribution of this e-mail, in whole or in part, is strictly prohibited. Please notify the sender by return e-mail and delete this e-mail from your system. Unless explicitly and conspicuously designated as "E-Contract Intended", this e-mail does not constitute a contract offer, a contract amendment, or an acceptance of a contract offer. This e-mail does not constitute a consent to the use of sender's contact information for direct marketing purposes or for transfers of data to third parties. Francais Deutsch Italiano Espanol Portugues Japanese Chinese Korean http://www.DuPont.com/corp/email_disclaimer.html ```