On 2014-12-02 03:22, Graeme Gill wrote: > Michal Soltys wrote: > >> ICC faq: There is and should be no chromatic adaptation relationship between >> ICC >> media relative colorimetric and ICC absolute colorimetric - it should >> just be a scaling relationship so the data is either scaled to the media >> white == max PCS value or scaled to the illuminant white == max PCS value. > > Saying something is "merely scaling" doesn't make it so. That it is > not so, is easy to refute - you just have to examine what's happening > for tinted media. With tinted media, there is no doubt at all that > the viewer chromatically adapts to the color of the it, which is > why the whites of images printed on it, look white. Yet ICC applies > "Wrong" Von Kries in accounting for the difference between the D50 > illuminant and the media color. >
But the example you gave assumes that user is adapted to media white one is looking at (e.g. book's white) - not to illuminant used (to illuminate the book) ? From what I understand - the latter is what ICC assumes - in their "model" user is always adapted to illuminant. If we assumed that we were adapted to media white point - then it's obviously "Wrong" Von Kries with expected side effects. But if we assume adaptation to illuminant (which would imply tint), then it's not really "Wrong" Von Kries (even if math remains the same) ? Just trying to make some sense of what ICC tried to do here. ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
