[EMAIL PROTECTED] wrote: > 1) In your reply you specified it is generally possible to recreate > object measurement data from LUTs in ICC profile. Could you give me some > pointers on how we can do this?
The base information in an ICC profile is the relative colorimetric transformation. Given that and the white point, the absolute colorimetric response of the device is available. In most situations this exactly corresponds to instrument readings (one case where it does not, is ICC V4 display profiles, but this issue was discussed on this list some time ago - check the archives). The schema for all the WCS profiles and a fair amount of explanatory detail has been published by Microsoft - <http://blogs.msdn.com/color_blog/> is a good place to start to find this stuff. Simply put the two together :-) > 2) You said ICC do not create "transforms on the fly". But in ICM 2.0, > where WCS was not present at all, we could see the API > "CreateColorTransform". As per my understanding (and your comments) this > API links the two color transforms and creates one color transform out > of it which can be used by user application to do the color management > in one shot. Yes. But the gamut mapping and inversion of the device behaviour is all pre-computed in the ICC profile, so the CMM isn't doing anything interesting. > 3) Will WCS profiles in any way contain transforms in their LUTs? For > example let me sight the following tags from WCS cdmp schema. > > <xs:complexType name="OneDimensionLutType"> <xs:sequence> <xs:element > name="Input" type="cdm:FloatList"/> <xs:element name="Output" > type="cdm:FloatList"/> </xs:sequence> </xs:complexType> > > <xs:complexType name="HDRToneResponseCurvesType"> <xs:sequence> > <xs:element name="RedTRC" type="cdm:OneDimensionLutType"/> <xs:element > name="GreenTRC" type="cdm:OneDimensionLutType"/> <xs:element > name="BlueTRC" type="cdm:OneDimensionLutType"/> </xs:sequence> > > Like other tags in WCS do these tags contain only object measurement > data? So it is claimed. In practice this might be massaged measurement data. Graeme Gill. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
