Hello Marti, Thank you for the quick reply. The Lab-2-Lab conversion with different illuminants is just first step in my conversion. Then I apply an ICC profile and convert to RGB with the relative colorimetric intent. Is possible to create a multi-profile transform with different intents for each transformation? I do not see this as an option in LittleCMS.
Or I should create two transforms: one transform Lab2Lab with these settings and then the new Lab values convert from this custom illuminant Lab space with my ICC profile to RGB values? One other small thing. I tried using cmsWhitePointFromTemp(&White, temp); cmsCreateLab4Profile(&White); and a transformation from Lab to RGB with an ICC profile gave me the same results for every temperature I used. I use relative colorimetric intent. Any ideas what could be an issue here? Thank you. Regards, Martin On 15.11.2013 12:30, marti.ma...@littlecms.com wrote: > > Quoting Martin Florek <mflo...@gmail.com>: > >> Hello, >> I would like to convert a D50 Lab values to Lab values for a different >> color temperature illuminant. Is this possible with Little CMS, and if >> then how? Tahnk you. > > > Hi Martin, > > Yes, it is certainly possible. > > - Create A D50 Lab profile by using > > cmsCreateLab4Profile(NULL) > > - Get the chromaticity of color temperature and use it as black-body > white point > > cmsWhitePointFromTemp(&White, temp); > cmsCreateLab4Profile(&White); > > - Set adaptation state to unadapted > > cmsSetAdaptationState(0); > > - Then create the transform by using absolute colorimetric intent. > > You can check this by using transicc: > > C:\lcms2-2.6\bin>transicc -i*Lab -o*LabD65 -t3 -d0 > LittleCMS ColorSpace conversion calculator - 4.2 [LittleCMS 2.06] > > Enter values, 'q' to quit > L*? 100 > a*? 0 > b*? 0 > > L*=100.1896 a*=3.9640 b*=17.8366 > > Regards > Marti > ------------------------------------------------------------------------------ DreamFactory - Open Source REST & JSON Services for HTML5 & Native Apps OAuth, Users, Roles, SQL, NoSQL, BLOB Storage and External API Access Free app hosting. Or install the open source package on any LAMP server. Sign up and see examples for AngularJS, jQuery, Sencha Touch and Native! http://pubads.g.doubleclick.net/gampad/clk?id=63469471&iu=/4140/ostg.clktrk _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
