Carles Llopis wrote: > To do this conversion we must adapt the spot color Lab to D50 prior to > convert it to the > profile, isn't it ?
Yes. The measurements for a (reflective) ICC profile should be as if they had been measured under D50. Typically instruments do this conversion for you (ie. they use an incandescent or LED light, convert to reflectance then multiply by D50 to give D50 XYZ values). So to best conform to the ICC expectation you should change your instrument to produce D50 measurements (or do it yourself from the spectral data). If you think that a D65 illuminant is actually more representative of your viewing conditions, then alternatively you could chromatically adapt the XYZ from D65 to D50 measurement, and then put this in the chromatic adaptation tag (although this tag will not likely be ever used for anything for a reflective profile). Of course there is nothing to stop you simply feeding in the D65 data as if it was D50 data, as the profiler will convert it to relative colorimetric - it will just have a very blue looking white point, which will only show up if you use absolute colorimetric intent. The standard ICC chromatic adaptation algorithm for this is a poor one though (so called "Wrong Von Kries"). Graeme Gill. ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d _______________________________________________ Lcms-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/lcms-user
