Marti, thanks for the explanation. May I ask for another simpler "theory" example. Meaning, I have the following three profiles; sRGB.icc describes RGB->lab, based on measured data OutputMediaRGB.icc describes RGB->lab, and vendor provided OutputDevice.icc describes lab->CMYK.
My uneducated guess is that there is more to do than just concatenating A2B and B2A tables from three files. If possible, can you please explain conceptually how the concatenation of LUT's will get us the desired RGB->CMYK DeviceLink profile? Pick one intent for the easiest explanation and assume all LUTS are 17^3. Once again I appreciate the education, Andrei -----Original Message----- From: marti.ma...@littlecms.com [mailto:marti.ma...@littlecms.com] Sent: Thursday, March 29, 2012 1:38 PM To: Andrei Szeghy Cc: lcms-user@lists.sourceforge.net Subject: Re: [Lcms-user] Device Link creation info Hi Andrei, A devicelink of several profiles is just the concatenation of the LUTs for each intent. Seems easy in theory but it has its challanges. For example, if the intent is absolute colorimetric, some scaling should be done from LUT to LUT. Same for black point compensation. Also, if the involved profiles are named colors ones, the procedure is completly different and then each spot color has to be evaluated across the composite transform. Finally, ICC file format does not allow an arbitrary number of stages in the LUT, so it is up to the CMM to optimize and reduce the number of stages keeping proper precision. This is the most difficult part. Regards Marti > Hello, > > > > I'm trying to get details on how a device-link profile is created. > Not the syntax to make the LCMS call, but how each profile is > contributing to the final device-link profile. For example, consider > an sRGB printer application and three profiles; One (input) is the > sRGB colorspace, two > (output) RGB profile for target media, and third is the "raw" device > dependent RGB->CMYK provided by the print vendor. All three are > magically melted together using LCMS. > > > > If anyone could provide some insight or point to a reference it > would be greatly appreciated! Thanks, > > Andrei > > ------------------------------------------------------------------------------ This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
