Thanks, Kai-Uwe, I'll do that. I'm afraid, though, that visualizing the internals of the profiles doesn't help.
I have generated several profiles. - CLUT with 17, 33 and 65 nodes - CLUT plus prelinearization curves (17, or 33 or 65 steps, shifted to center them around the nodes) - CLUT, plus prelinearization curves, plus postlinearization curves (to clamp c,m,y,k values) The profiles look perfect, as I expected them to be when I designed them. Is its application wat puzzles me. My test consists in applying icctrans to an IT8 file with 7 256-step ramps of RGB values (sRGB),as in icctrans -o <profile> test_rgb.it8 test_cmyk.it8 Most of the time, the result is the expected one. But in all the different profiles I have built, the tests show glitches, and I can find RGB values that do not map to the desired output. It is weird, for instance, that clamping does not produce a clean, rounded number. And the presence of mis-behaving values here and there, not only in the border of the regions. Maybe the rounding and interpolation is a limitation I can't avoid,and with deeper effects than I expected. You can find sources in http://docs.google.com/Doc?id=dfscpqm8_45t4q5ffst It is a ZIP, but with a .txt extension, so that GoogleDocs allows me to upload it (other suggestions?) It contains several profiles, the source program (with an explanation of the goal to achieve) and the test file. There is also an spreadsheet with the results of the tests (see below), highlighted to show my concerns. Best regards, Ignacio Kai-Uwe Behrmann wrote: > Possibly posting a link to your profile(s) would help. > For most OSes exist profile inspection tools to see a nLUT, at least > for version 2.x. For the ICC version 4.x it may differ. > > kind regards > Kai-Uwe Behrmann -- ______________________________________________________________ Ignacio Ruiz de Conejo Senior Imaging Researcher Tel. : +61 28875 9682 e-mail: ignacio.ruizdecon...@silverbrookresearch.com ______________________________________________________________ ------------------------------------------------------------------------------ Stay on top of everything new and different, both inside and around Java (TM) technology - register by April 22, and save $200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco. 300 plus technical and hands-on sessions. Register today. Use priority code J9JMT32. http://p.sf.net/sfu/p _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
